| /* Expands front end tree to back end RTL for GNU C-Compiler |
| Copyright (C) 1987, 88, 89, 92-6, 1997 Free Software Foundation, Inc. |
| |
| This file is part of GNU CC. |
| |
| GNU CC is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU CC is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU CC; see the file COPYING. If not, write to |
| the Free Software Foundation, 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| |
| /* This file handles the generation of rtl code from tree structure |
| above the level of expressions, using subroutines in exp*.c and emit-rtl.c. |
| It also creates the rtl expressions for parameters and auto variables |
| and has full responsibility for allocating stack slots. |
| |
| The functions whose names start with `expand_' are called by the |
| parser to generate RTL instructions for various kinds of constructs. |
| |
| Some control and binding constructs require calling several such |
| functions at different times. For example, a simple if-then |
| is expanded by calling `expand_start_cond' (with the condition-expression |
| as argument) before parsing the then-clause and calling `expand_end_cond' |
| after parsing the then-clause. */ |
| |
| #include "config.h" |
| |
| #include <stdio.h> |
| #include <ctype.h> |
| |
| #include "rtl.h" |
| #include "tree.h" |
| #include "flags.h" |
| #include "except.h" |
| #include "function.h" |
| #include "insn-flags.h" |
| #include "insn-config.h" |
| #include "insn-codes.h" |
| #include "expr.h" |
| #include "hard-reg-set.h" |
| #include "obstack.h" |
| #include "loop.h" |
| #include "recog.h" |
| #include "machmode.h" |
| |
| #include "bytecode.h" |
| #include "bc-typecd.h" |
| #include "bc-opcode.h" |
| #include "bc-optab.h" |
| #include "bc-emit.h" |
| |
| #define obstack_chunk_alloc xmalloc |
| #define obstack_chunk_free free |
| struct obstack stmt_obstack; |
| |
| /* Filename and line number of last line-number note, |
| whether we actually emitted it or not. */ |
| char *emit_filename; |
| int emit_lineno; |
| |
| /* Nonzero if within a ({...}) grouping, in which case we must |
| always compute a value for each expr-stmt in case it is the last one. */ |
| |
| int expr_stmts_for_value; |
| |
| /* Each time we expand an expression-statement, |
| record the expr's type and its RTL value here. */ |
| |
| static tree last_expr_type; |
| static rtx last_expr_value; |
| |
| /* Each time we expand the end of a binding contour (in `expand_end_bindings') |
| and we emit a new NOTE_INSN_BLOCK_END note, we save a pointer to it here. |
| This is used by the `remember_end_note' function to record the endpoint |
| of each generated block in its associated BLOCK node. */ |
| |
| static rtx last_block_end_note; |
| |
| /* Number of binding contours started so far in this function. */ |
| |
| int block_start_count; |
| |
| /* Nonzero if function being compiled needs to |
| return the address of where it has put a structure value. */ |
| |
| extern int current_function_returns_pcc_struct; |
| |
| /* Label that will go on parm cleanup code, if any. |
| Jumping to this label runs cleanup code for parameters, if |
| such code must be run. Following this code is the logical return label. */ |
| |
| extern rtx cleanup_label; |
| |
| /* Label that will go on function epilogue. |
| Jumping to this label serves as a "return" instruction |
| on machines which require execution of the epilogue on all returns. */ |
| |
| extern rtx return_label; |
| |
| /* Offset to end of allocated area of stack frame. |
| If stack grows down, this is the address of the last stack slot allocated. |
| If stack grows up, this is the address for the next slot. */ |
| extern int frame_offset; |
| |
| /* Label to jump back to for tail recursion, or 0 if we have |
| not yet needed one for this function. */ |
| extern rtx tail_recursion_label; |
| |
| /* Place after which to insert the tail_recursion_label if we need one. */ |
| extern rtx tail_recursion_reentry; |
| |
| /* Location at which to save the argument pointer if it will need to be |
| referenced. There are two cases where this is done: if nonlocal gotos |
| exist, or if vars whose is an offset from the argument pointer will be |
| needed by inner routines. */ |
| |
| extern rtx arg_pointer_save_area; |
| |
| /* Chain of all RTL_EXPRs that have insns in them. */ |
| extern tree rtl_expr_chain; |
| |
| /* Stack allocation level in which temporaries for TARGET_EXPRs live. */ |
| extern int target_temp_slot_level; |
| |
| extern int temp_slot_level; |
| |
| /* Functions and data structures for expanding case statements. */ |
| |
| /* Case label structure, used to hold info on labels within case |
| statements. We handle "range" labels; for a single-value label |
| as in C, the high and low limits are the same. |
| |
| An AVL tree of case nodes is initially created, and later transformed |
| to a list linked via the RIGHT fields in the nodes. Nodes with |
| higher case values are later in the list. |
| |
| Switch statements can be output in one of two forms. A branch table |
| is used if there are more than a few labels and the labels are dense |
| within the range between the smallest and largest case value. If a |
| branch table is used, no further manipulations are done with the case |
| node chain. |
| |
| The alternative to the use of a branch table is to generate a series |
| of compare and jump insns. When that is done, we use the LEFT, RIGHT, |
| and PARENT fields to hold a binary tree. Initially the tree is |
| totally unbalanced, with everything on the right. We balance the tree |
| with nodes on the left having lower case values than the parent |
| and nodes on the right having higher values. We then output the tree |
| in order. */ |
| |
| struct case_node |
| { |
| struct case_node *left; /* Left son in binary tree */ |
| struct case_node *right; /* Right son in binary tree; also node chain */ |
| struct case_node *parent; /* Parent of node in binary tree */ |
| tree low; /* Lowest index value for this label */ |
| tree high; /* Highest index value for this label */ |
| tree code_label; /* Label to jump to when node matches */ |
| int balance; |
| }; |
| |
| typedef struct case_node case_node; |
| typedef struct case_node *case_node_ptr; |
| |
| /* These are used by estimate_case_costs and balance_case_nodes. */ |
| |
| /* This must be a signed type, and non-ANSI compilers lack signed char. */ |
| static short *cost_table; |
| static int use_cost_table; |
| |
| /* Stack of control and binding constructs we are currently inside. |
| |
| These constructs begin when you call `expand_start_WHATEVER' |
| and end when you call `expand_end_WHATEVER'. This stack records |
| info about how the construct began that tells the end-function |
| what to do. It also may provide information about the construct |
| to alter the behavior of other constructs within the body. |
| For example, they may affect the behavior of C `break' and `continue'. |
| |
| Each construct gets one `struct nesting' object. |
| All of these objects are chained through the `all' field. |
| `nesting_stack' points to the first object (innermost construct). |
| The position of an entry on `nesting_stack' is in its `depth' field. |
| |
| Each type of construct has its own individual stack. |
| For example, loops have `loop_stack'. Each object points to the |
| next object of the same type through the `next' field. |
| |
| Some constructs are visible to `break' exit-statements and others |
| are not. Which constructs are visible depends on the language. |
| Therefore, the data structure allows each construct to be visible |
| or not, according to the args given when the construct is started. |
| The construct is visible if the `exit_label' field is non-null. |
| In that case, the value should be a CODE_LABEL rtx. */ |
| |
| struct nesting |
| { |
| struct nesting *all; |
| struct nesting *next; |
| int depth; |
| rtx exit_label; |
| union |
| { |
| /* For conds (if-then and if-then-else statements). */ |
| struct |
| { |
| /* Label for the end of the if construct. |
| There is none if EXITFLAG was not set |
| and no `else' has been seen yet. */ |
| rtx endif_label; |
| /* Label for the end of this alternative. |
| This may be the end of the if or the next else/elseif. */ |
| rtx next_label; |
| } cond; |
| /* For loops. */ |
| struct |
| { |
| /* Label at the top of the loop; place to loop back to. */ |
| rtx start_label; |
| /* Label at the end of the whole construct. */ |
| rtx end_label; |
| /* Label before a jump that branches to the end of the whole |
| construct. This is where destructors go if any. */ |
| rtx alt_end_label; |
| /* Label for `continue' statement to jump to; |
| this is in front of the stepper of the loop. */ |
| rtx continue_label; |
| } loop; |
| /* For variable binding contours. */ |
| struct |
| { |
| /* Sequence number of this binding contour within the function, |
| in order of entry. */ |
| int block_start_count; |
| /* Nonzero => value to restore stack to on exit. Complemented by |
| bc_stack_level (see below) when generating bytecodes. */ |
| rtx stack_level; |
| /* The NOTE that starts this contour. |
| Used by expand_goto to check whether the destination |
| is within each contour or not. */ |
| rtx first_insn; |
| /* Innermost containing binding contour that has a stack level. */ |
| struct nesting *innermost_stack_block; |
| /* List of cleanups to be run on exit from this contour. |
| This is a list of expressions to be evaluated. |
| The TREE_PURPOSE of each link is the ..._DECL node |
| which the cleanup pertains to. */ |
| tree cleanups; |
| /* List of cleanup-lists of blocks containing this block, |
| as they were at the locus where this block appears. |
| There is an element for each containing block, |
| ordered innermost containing block first. |
| The tail of this list can be 0, |
| if all remaining elements would be empty lists. |
| The element's TREE_VALUE is the cleanup-list of that block, |
| which may be null. */ |
| tree outer_cleanups; |
| /* Chain of labels defined inside this binding contour. |
| For contours that have stack levels or cleanups. */ |
| struct label_chain *label_chain; |
| /* Number of function calls seen, as of start of this block. */ |
| int function_call_count; |
| /* Bytecode specific: stack level to restore stack to on exit. */ |
| int bc_stack_level; |
| /* Nonzero if this is associated with a EH region. */ |
| int exception_region; |
| /* The saved target_temp_slot_level from our outer block. |
| We may reset target_temp_slot_level to be the level of |
| this block, if that is done, target_temp_slot_level |
| reverts to the saved target_temp_slot_level at the very |
| end of the block. */ |
| int target_temp_slot_level; |
| /* True if we are currently emitting insns in an area of |
| output code that is controlled by a conditional |
| expression. This is used by the cleanup handling code to |
| generate conditional cleanup actions. */ |
| int conditional_code; |
| /* A place to move the start of the exception region for any |
| of the conditional cleanups, must be at the end or after |
| the start of the last unconditional cleanup, and before any |
| conditional branch points. */ |
| rtx last_unconditional_cleanup; |
| /* When in a conditional context, this is the specific |
| cleanup list associated with last_unconditional_cleanup, |
| where we place the conditionalized cleanups. */ |
| tree *cleanup_ptr; |
| } block; |
| /* For switch (C) or case (Pascal) statements, |
| and also for dummies (see `expand_start_case_dummy'). */ |
| struct |
| { |
| /* The insn after which the case dispatch should finally |
| be emitted. Zero for a dummy. */ |
| rtx start; |
| /* For bytecodes, the case table is in-lined right in the code. |
| A label is needed for skipping over this block. It is only |
| used when generating bytecodes. */ |
| rtx skip_label; |
| /* A list of case labels; it is first built as an AVL tree. |
| During expand_end_case, this is converted to a list, and may be |
| rearranged into a nearly balanced binary tree. */ |
| struct case_node *case_list; |
| /* Label to jump to if no case matches. */ |
| tree default_label; |
| /* The expression to be dispatched on. */ |
| tree index_expr; |
| /* Type that INDEX_EXPR should be converted to. */ |
| tree nominal_type; |
| /* Number of range exprs in case statement. */ |
| int num_ranges; |
| /* Name of this kind of statement, for warnings. */ |
| char *printname; |
| /* Nonzero if a case label has been seen in this case stmt. */ |
| char seenlabel; |
| } case_stmt; |
| } data; |
| }; |
| |
| /* Chain of all pending binding contours. */ |
| struct nesting *block_stack; |
| |
| /* If any new stacks are added here, add them to POPSTACKS too. */ |
| |
| /* Chain of all pending binding contours that restore stack levels |
| or have cleanups. */ |
| struct nesting *stack_block_stack; |
| |
| /* Chain of all pending conditional statements. */ |
| struct nesting *cond_stack; |
| |
| /* Chain of all pending loops. */ |
| struct nesting *loop_stack; |
| |
| /* Chain of all pending case or switch statements. */ |
| struct nesting *case_stack; |
| |
| /* Separate chain including all of the above, |
| chained through the `all' field. */ |
| struct nesting *nesting_stack; |
| |
| /* Number of entries on nesting_stack now. */ |
| int nesting_depth; |
| |
| /* Allocate and return a new `struct nesting'. */ |
| |
| #define ALLOC_NESTING() \ |
| (struct nesting *) obstack_alloc (&stmt_obstack, sizeof (struct nesting)) |
| |
| /* Pop the nesting stack element by element until we pop off |
| the element which is at the top of STACK. |
| Update all the other stacks, popping off elements from them |
| as we pop them from nesting_stack. */ |
| |
| #define POPSTACK(STACK) \ |
| do { struct nesting *target = STACK; \ |
| struct nesting *this; \ |
| do { this = nesting_stack; \ |
| if (loop_stack == this) \ |
| loop_stack = loop_stack->next; \ |
| if (cond_stack == this) \ |
| cond_stack = cond_stack->next; \ |
| if (block_stack == this) \ |
| block_stack = block_stack->next; \ |
| if (stack_block_stack == this) \ |
| stack_block_stack = stack_block_stack->next; \ |
| if (case_stack == this) \ |
| case_stack = case_stack->next; \ |
| nesting_depth = nesting_stack->depth - 1; \ |
| nesting_stack = this->all; \ |
| obstack_free (&stmt_obstack, this); } \ |
| while (this != target); } while (0) |
| |
| /* In some cases it is impossible to generate code for a forward goto |
| until the label definition is seen. This happens when it may be necessary |
| for the goto to reset the stack pointer: we don't yet know how to do that. |
| So expand_goto puts an entry on this fixup list. |
| Each time a binding contour that resets the stack is exited, |
| we check each fixup. |
| If the target label has now been defined, we can insert the proper code. */ |
| |
| struct goto_fixup |
| { |
| /* Points to following fixup. */ |
| struct goto_fixup *next; |
| /* Points to the insn before the jump insn. |
| If more code must be inserted, it goes after this insn. */ |
| rtx before_jump; |
| /* The LABEL_DECL that this jump is jumping to, or 0 |
| for break, continue or return. */ |
| tree target; |
| /* The BLOCK for the place where this goto was found. */ |
| tree context; |
| /* The CODE_LABEL rtx that this is jumping to. */ |
| rtx target_rtl; |
| /* Number of binding contours started in current function |
| before the label reference. */ |
| int block_start_count; |
| /* The outermost stack level that should be restored for this jump. |
| Each time a binding contour that resets the stack is exited, |
| if the target label is *not* yet defined, this slot is updated. */ |
| rtx stack_level; |
| /* List of lists of cleanup expressions to be run by this goto. |
| There is one element for each block that this goto is within. |
| The tail of this list can be 0, |
| if all remaining elements would be empty. |
| The TREE_VALUE contains the cleanup list of that block as of the |
| time this goto was seen. |
| The TREE_ADDRESSABLE flag is 1 for a block that has been exited. */ |
| tree cleanup_list_list; |
| |
| /* Bytecode specific members follow */ |
| |
| /* The label that this jump is jumping to, or 0 for break, continue |
| or return. */ |
| struct bc_label *bc_target; |
| |
| /* The label we use for the fixup patch */ |
| struct bc_label *label; |
| |
| /* True (non-0) if fixup has been handled */ |
| int bc_handled:1; |
| |
| /* Like stack_level above, except refers to the interpreter stack */ |
| int bc_stack_level; |
| }; |
| |
| static struct goto_fixup *goto_fixup_chain; |
| |
| /* Within any binding contour that must restore a stack level, |
| all labels are recorded with a chain of these structures. */ |
| |
| struct label_chain |
| { |
| /* Points to following fixup. */ |
| struct label_chain *next; |
| tree label; |
| }; |
| |
| |
| /* Non-zero if we are using EH to handle cleanus. */ |
| static int using_eh_for_cleanups_p = 0; |
| |
| |
| static void expand_goto_internal PROTO((tree, rtx, rtx)); |
| static void bc_expand_goto_internal PROTO((enum bytecode_opcode, |
| struct bc_label *, tree)); |
| static int expand_fixup PROTO((tree, rtx, rtx)); |
| static void bc_expand_fixup PROTO((enum bytecode_opcode, |
| struct bc_label *, int)); |
| static void fixup_gotos PROTO((struct nesting *, rtx, tree, |
| rtx, int)); |
| static void bc_fixup_gotos PROTO((struct nesting *, int, tree, |
| rtx, int)); |
| static void bc_expand_start_cond PROTO((tree, int)); |
| static void bc_expand_end_cond PROTO((void)); |
| static void bc_expand_start_else PROTO((void)); |
| static void bc_expand_end_loop PROTO((void)); |
| static void bc_expand_end_bindings PROTO((tree, int, int)); |
| static void bc_expand_decl PROTO((tree, tree)); |
| static void bc_expand_variable_local_init PROTO((tree)); |
| static void bc_expand_decl_init PROTO((tree)); |
| static void expand_null_return_1 PROTO((rtx, int)); |
| static void expand_value_return PROTO((rtx)); |
| static int tail_recursion_args PROTO((tree, tree)); |
| static void expand_cleanups PROTO((tree, tree, int, int)); |
| static void bc_expand_start_case PROTO((struct nesting *, tree, |
| tree, char *)); |
| static int bc_pushcase PROTO((tree, tree)); |
| static void bc_check_for_full_enumeration_handling PROTO((tree)); |
| static void bc_expand_end_case PROTO((tree)); |
| static void do_jump_if_equal PROTO((rtx, rtx, rtx, int)); |
| static int estimate_case_costs PROTO((case_node_ptr)); |
| static void group_case_nodes PROTO((case_node_ptr)); |
| static void balance_case_nodes PROTO((case_node_ptr *, |
| case_node_ptr)); |
| static int node_has_low_bound PROTO((case_node_ptr, tree)); |
| static int node_has_high_bound PROTO((case_node_ptr, tree)); |
| static int node_is_bounded PROTO((case_node_ptr, tree)); |
| static void emit_jump_if_reachable PROTO((rtx)); |
| static void emit_case_nodes PROTO((rtx, case_node_ptr, rtx, tree)); |
| static int add_case_node PROTO((tree, tree, tree, tree *)); |
| static struct case_node *case_tree2list PROTO((case_node *, case_node *)); |
| |
| extern rtx bc_allocate_local (); |
| extern rtx bc_allocate_variable_array (); |
| |
| void |
| using_eh_for_cleanups () |
| { |
| using_eh_for_cleanups_p = 1; |
| } |
| |
| void |
| init_stmt () |
| { |
| gcc_obstack_init (&stmt_obstack); |
| init_eh (); |
| } |
| |
| void |
| init_stmt_for_function () |
| { |
| /* We are not currently within any block, conditional, loop or case. */ |
| block_stack = 0; |
| stack_block_stack = 0; |
| loop_stack = 0; |
| case_stack = 0; |
| cond_stack = 0; |
| nesting_stack = 0; |
| nesting_depth = 0; |
| |
| block_start_count = 0; |
| |
| /* No gotos have been expanded yet. */ |
| goto_fixup_chain = 0; |
| |
| /* We are not processing a ({...}) grouping. */ |
| expr_stmts_for_value = 0; |
| last_expr_type = 0; |
| |
| init_eh_for_function (); |
| } |
| |
| void |
| save_stmt_status (p) |
| struct function *p; |
| { |
| p->block_stack = block_stack; |
| p->stack_block_stack = stack_block_stack; |
| p->cond_stack = cond_stack; |
| p->loop_stack = loop_stack; |
| p->case_stack = case_stack; |
| p->nesting_stack = nesting_stack; |
| p->nesting_depth = nesting_depth; |
| p->block_start_count = block_start_count; |
| p->last_expr_type = last_expr_type; |
| p->last_expr_value = last_expr_value; |
| p->expr_stmts_for_value = expr_stmts_for_value; |
| p->emit_filename = emit_filename; |
| p->emit_lineno = emit_lineno; |
| p->goto_fixup_chain = goto_fixup_chain; |
| save_eh_status (p); |
| } |
| |
| void |
| restore_stmt_status (p) |
| struct function *p; |
| { |
| block_stack = p->block_stack; |
| stack_block_stack = p->stack_block_stack; |
| cond_stack = p->cond_stack; |
| loop_stack = p->loop_stack; |
| case_stack = p->case_stack; |
| nesting_stack = p->nesting_stack; |
| nesting_depth = p->nesting_depth; |
| block_start_count = p->block_start_count; |
| last_expr_type = p->last_expr_type; |
| last_expr_value = p->last_expr_value; |
| expr_stmts_for_value = p->expr_stmts_for_value; |
| emit_filename = p->emit_filename; |
| emit_lineno = p->emit_lineno; |
| goto_fixup_chain = p->goto_fixup_chain; |
| restore_eh_status (p); |
| } |
| |
| /* Emit a no-op instruction. */ |
| |
| void |
| emit_nop () |
| { |
| rtx last_insn; |
| |
| if (!output_bytecode) |
| { |
| last_insn = get_last_insn (); |
| if (!optimize |
| && (GET_CODE (last_insn) == CODE_LABEL |
| || (GET_CODE (last_insn) == NOTE |
| && prev_real_insn (last_insn) == 0))) |
| emit_insn (gen_nop ()); |
| } |
| } |
| |
| /* Return the rtx-label that corresponds to a LABEL_DECL, |
| creating it if necessary. */ |
| |
| rtx |
| label_rtx (label) |
| tree label; |
| { |
| if (TREE_CODE (label) != LABEL_DECL) |
| abort (); |
| |
| if (DECL_RTL (label)) |
| return DECL_RTL (label); |
| |
| return DECL_RTL (label) = gen_label_rtx (); |
| } |
| |
| /* Add an unconditional jump to LABEL as the next sequential instruction. */ |
| |
| void |
| emit_jump (label) |
| rtx label; |
| { |
| do_pending_stack_adjust (); |
| emit_jump_insn (gen_jump (label)); |
| emit_barrier (); |
| } |
| |
| /* Emit code to jump to the address |
| specified by the pointer expression EXP. */ |
| |
| void |
| expand_computed_goto (exp) |
| tree exp; |
| { |
| if (output_bytecode) |
| { |
| bc_expand_expr (exp); |
| bc_emit_instruction (jumpP); |
| } |
| else |
| { |
| rtx x = expand_expr (exp, NULL_RTX, VOIDmode, 0); |
| |
| #ifdef POINTERS_EXTEND_UNSIGNED |
| x = convert_memory_address (Pmode, x); |
| #endif |
| |
| emit_queue (); |
| /* Be sure the function is executable. */ |
| if (flag_check_memory_usage) |
| emit_library_call (chkr_check_exec_libfunc, 1, |
| VOIDmode, 1, x, ptr_mode); |
| |
| do_pending_stack_adjust (); |
| emit_indirect_jump (x); |
| } |
| } |
| |
| /* Handle goto statements and the labels that they can go to. */ |
| |
| /* Specify the location in the RTL code of a label LABEL, |
| which is a LABEL_DECL tree node. |
| |
| This is used for the kind of label that the user can jump to with a |
| goto statement, and for alternatives of a switch or case statement. |
| RTL labels generated for loops and conditionals don't go through here; |
| they are generated directly at the RTL level, by other functions below. |
| |
| Note that this has nothing to do with defining label *names*. |
| Languages vary in how they do that and what that even means. */ |
| |
| void |
| expand_label (label) |
| tree label; |
| { |
| struct label_chain *p; |
| |
| if (output_bytecode) |
| { |
| if (! DECL_RTL (label)) |
| DECL_RTL (label) = bc_gen_rtx ((char *) 0, 0, bc_get_bytecode_label ()); |
| if (! bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (DECL_RTL (label)))) |
| error ("multiply defined label"); |
| return; |
| } |
| |
| do_pending_stack_adjust (); |
| emit_label (label_rtx (label)); |
| if (DECL_NAME (label)) |
| LABEL_NAME (DECL_RTL (label)) = IDENTIFIER_POINTER (DECL_NAME (label)); |
| |
| if (stack_block_stack != 0) |
| { |
| p = (struct label_chain *) oballoc (sizeof (struct label_chain)); |
| p->next = stack_block_stack->data.block.label_chain; |
| stack_block_stack->data.block.label_chain = p; |
| p->label = label; |
| } |
| } |
| |
| /* Declare that LABEL (a LABEL_DECL) may be used for nonlocal gotos |
| from nested functions. */ |
| |
| void |
| declare_nonlocal_label (label) |
| tree label; |
| { |
| nonlocal_labels = tree_cons (NULL_TREE, label, nonlocal_labels); |
| LABEL_PRESERVE_P (label_rtx (label)) = 1; |
| if (nonlocal_goto_handler_slot == 0) |
| { |
| nonlocal_goto_handler_slot |
| = assign_stack_local (Pmode, GET_MODE_SIZE (Pmode), 0); |
| emit_stack_save (SAVE_NONLOCAL, |
| &nonlocal_goto_stack_level, |
| PREV_INSN (tail_recursion_reentry)); |
| } |
| } |
| |
| /* Generate RTL code for a `goto' statement with target label LABEL. |
| LABEL should be a LABEL_DECL tree node that was or will later be |
| defined with `expand_label'. */ |
| |
| void |
| expand_goto (label) |
| tree label; |
| { |
| tree context; |
| |
| if (output_bytecode) |
| { |
| expand_goto_internal (label, label_rtx (label), NULL_RTX); |
| return; |
| } |
| |
| /* Check for a nonlocal goto to a containing function. */ |
| context = decl_function_context (label); |
| if (context != 0 && context != current_function_decl) |
| { |
| struct function *p = find_function_data (context); |
| rtx label_ref = gen_rtx (LABEL_REF, Pmode, label_rtx (label)); |
| rtx temp; |
| |
| p->has_nonlocal_label = 1; |
| current_function_has_nonlocal_goto = 1; |
| LABEL_REF_NONLOCAL_P (label_ref) = 1; |
| |
| /* Copy the rtl for the slots so that they won't be shared in |
| case the virtual stack vars register gets instantiated differently |
| in the parent than in the child. */ |
| |
| #if HAVE_nonlocal_goto |
| if (HAVE_nonlocal_goto) |
| emit_insn (gen_nonlocal_goto (lookup_static_chain (label), |
| copy_rtx (p->nonlocal_goto_handler_slot), |
| copy_rtx (p->nonlocal_goto_stack_level), |
| label_ref)); |
| else |
| #endif |
| { |
| rtx addr; |
| |
| /* Restore frame pointer for containing function. |
| This sets the actual hard register used for the frame pointer |
| to the location of the function's incoming static chain info. |
| The non-local goto handler will then adjust it to contain the |
| proper value and reload the argument pointer, if needed. */ |
| emit_move_insn (hard_frame_pointer_rtx, lookup_static_chain (label)); |
| |
| /* We have now loaded the frame pointer hardware register with |
| the address of that corresponds to the start of the virtual |
| stack vars. So replace virtual_stack_vars_rtx in all |
| addresses we use with stack_pointer_rtx. */ |
| |
| /* Get addr of containing function's current nonlocal goto handler, |
| which will do any cleanups and then jump to the label. */ |
| addr = copy_rtx (p->nonlocal_goto_handler_slot); |
| temp = copy_to_reg (replace_rtx (addr, virtual_stack_vars_rtx, |
| hard_frame_pointer_rtx)); |
| |
| /* Restore the stack pointer. Note this uses fp just restored. */ |
| addr = p->nonlocal_goto_stack_level; |
| if (addr) |
| addr = replace_rtx (copy_rtx (addr), |
| virtual_stack_vars_rtx, |
| hard_frame_pointer_rtx); |
| |
| emit_stack_restore (SAVE_NONLOCAL, addr, NULL_RTX); |
| |
| /* Put in the static chain register the nonlocal label address. */ |
| emit_move_insn (static_chain_rtx, label_ref); |
| /* USE of hard_frame_pointer_rtx added for consistency; not clear if |
| really needed. */ |
| emit_insn (gen_rtx (USE, VOIDmode, hard_frame_pointer_rtx)); |
| emit_insn (gen_rtx (USE, VOIDmode, stack_pointer_rtx)); |
| emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx)); |
| emit_indirect_jump (temp); |
| } |
| } |
| else |
| expand_goto_internal (label, label_rtx (label), NULL_RTX); |
| } |
| |
| /* Generate RTL code for a `goto' statement with target label BODY. |
| LABEL should be a LABEL_REF. |
| LAST_INSN, if non-0, is the rtx we should consider as the last |
| insn emitted (for the purposes of cleaning up a return). */ |
| |
| static void |
| expand_goto_internal (body, label, last_insn) |
| tree body; |
| rtx label; |
| rtx last_insn; |
| { |
| struct nesting *block; |
| rtx stack_level = 0; |
| |
| /* NOTICE! If a bytecode instruction other than `jump' is needed, |
| then the caller has to call bc_expand_goto_internal() |
| directly. This is rather an exceptional case, and there aren't |
| that many places where this is necessary. */ |
| if (output_bytecode) |
| { |
| expand_goto_internal (body, label, last_insn); |
| return; |
| } |
| |
| if (GET_CODE (label) != CODE_LABEL) |
| abort (); |
| |
| /* If label has already been defined, we can tell now |
| whether and how we must alter the stack level. */ |
| |
| if (PREV_INSN (label) != 0) |
| { |
| /* Find the innermost pending block that contains the label. |
| (Check containment by comparing insn-uids.) |
| Then restore the outermost stack level within that block, |
| and do cleanups of all blocks contained in it. */ |
| for (block = block_stack; block; block = block->next) |
| { |
| if (INSN_UID (block->data.block.first_insn) < INSN_UID (label)) |
| break; |
| if (block->data.block.stack_level != 0) |
| stack_level = block->data.block.stack_level; |
| /* Execute the cleanups for blocks we are exiting. */ |
| if (block->data.block.cleanups != 0) |
| { |
| expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1); |
| do_pending_stack_adjust (); |
| } |
| } |
| |
| if (stack_level) |
| { |
| /* Ensure stack adjust isn't done by emit_jump, as this |
| would clobber the stack pointer. This one should be |
| deleted as dead by flow. */ |
| clear_pending_stack_adjust (); |
| do_pending_stack_adjust (); |
| emit_stack_restore (SAVE_BLOCK, stack_level, NULL_RTX); |
| } |
| |
| if (body != 0 && DECL_TOO_LATE (body)) |
| error ("jump to `%s' invalidly jumps into binding contour", |
| IDENTIFIER_POINTER (DECL_NAME (body))); |
| } |
| /* Label not yet defined: may need to put this goto |
| on the fixup list. */ |
| else if (! expand_fixup (body, label, last_insn)) |
| { |
| /* No fixup needed. Record that the label is the target |
| of at least one goto that has no fixup. */ |
| if (body != 0) |
| TREE_ADDRESSABLE (body) = 1; |
| } |
| |
| emit_jump (label); |
| } |
| |
| /* Generate a jump with OPCODE to the given bytecode LABEL which is |
| found within BODY. */ |
| |
| static void |
| bc_expand_goto_internal (opcode, label, body) |
| enum bytecode_opcode opcode; |
| struct bc_label *label; |
| tree body; |
| { |
| struct nesting *block; |
| int stack_level = -1; |
| |
| /* If the label is defined, adjust the stack as necessary. |
| If it's not defined, we have to push the reference on the |
| fixup list. */ |
| |
| if (label->defined) |
| { |
| |
| /* Find the innermost pending block that contains the label. |
| (Check containment by comparing bytecode uids.) Then restore the |
| outermost stack level within that block. */ |
| |
| for (block = block_stack; block; block = block->next) |
| { |
| if (BYTECODE_BC_LABEL (block->data.block.first_insn)->uid < label->uid) |
| break; |
| if (block->data.block.bc_stack_level) |
| stack_level = block->data.block.bc_stack_level; |
| |
| /* Execute the cleanups for blocks we are exiting. */ |
| if (block->data.block.cleanups != 0) |
| { |
| expand_cleanups (block->data.block.cleanups, NULL_TREE, 1, 1); |
| do_pending_stack_adjust (); |
| } |
| } |
| |
| /* Restore the stack level. If we need to adjust the stack, we |
| must do so after the jump, since the jump may depend on |
| what's on the stack. Thus, any stack-modifying conditional |
| jumps (these are the only ones that rely on what's on the |
| stack) go into the fixup list. */ |
| |
| if (stack_level >= 0 |
| && stack_depth != stack_level |
| && opcode != jump) |
| |
| bc_expand_fixup (opcode, label, stack_level); |
| else |
| { |
| if (stack_level >= 0) |
| bc_adjust_stack (stack_depth - stack_level); |
| |
| if (body && DECL_BIT_FIELD (body)) |
| error ("jump to `%s' invalidly jumps into binding contour", |
| IDENTIFIER_POINTER (DECL_NAME (body))); |
| |
| /* Emit immediate jump */ |
| bc_emit_bytecode (opcode); |
| bc_emit_bytecode_labelref (label); |
| |
| #ifdef DEBUG_PRINT_CODE |
| fputc ('\n', stderr); |
| #endif |
| } |
| } |
| else |
| /* Put goto in the fixup list */ |
| bc_expand_fixup (opcode, label, stack_level); |
| } |
| |
| /* Generate if necessary a fixup for a goto |
| whose target label in tree structure (if any) is TREE_LABEL |
| and whose target in rtl is RTL_LABEL. |
| |
| If LAST_INSN is nonzero, we pretend that the jump appears |
| after insn LAST_INSN instead of at the current point in the insn stream. |
| |
| The fixup will be used later to insert insns just before the goto. |
| Those insns will restore the stack level as appropriate for the |
| target label, and will (in the case of C++) also invoke any object |
| destructors which have to be invoked when we exit the scopes which |
| are exited by the goto. |
| |
| Value is nonzero if a fixup is made. */ |
| |
| static int |
| expand_fixup (tree_label, rtl_label, last_insn) |
| tree tree_label; |
| rtx rtl_label; |
| rtx last_insn; |
| { |
| struct nesting *block, *end_block; |
| |
| /* See if we can recognize which block the label will be output in. |
| This is possible in some very common cases. |
| If we succeed, set END_BLOCK to that block. |
| Otherwise, set it to 0. */ |
| |
| if (cond_stack |
| && (rtl_label == cond_stack->data.cond.endif_label |
| || rtl_label == cond_stack->data.cond.next_label)) |
| end_block = cond_stack; |
| /* If we are in a loop, recognize certain labels which |
| are likely targets. This reduces the number of fixups |
| we need to create. */ |
| else if (loop_stack |
| && (rtl_label == loop_stack->data.loop.start_label |
| || rtl_label == loop_stack->data.loop.end_label |
| || rtl_label == loop_stack->data.loop.continue_label)) |
| end_block = loop_stack; |
| else |
| end_block = 0; |
| |
| /* Now set END_BLOCK to the binding level to which we will return. */ |
| |
| if (end_block) |
| { |
| struct nesting *next_block = end_block->all; |
| block = block_stack; |
| |
| /* First see if the END_BLOCK is inside the innermost binding level. |
| If so, then no cleanups or stack levels are relevant. */ |
| while (next_block && next_block != block) |
| next_block = next_block->all; |
| |
| if (next_block) |
| return 0; |
| |
| /* Otherwise, set END_BLOCK to the innermost binding level |
| which is outside the relevant control-structure nesting. */ |
| next_block = block_stack->next; |
| for (block = block_stack; block != end_block; block = block->all) |
| if (block == next_block) |
| next_block = next_block->next; |
| end_block = next_block; |
| } |
| |
| /* Does any containing block have a stack level or cleanups? |
| If not, no fixup is needed, and that is the normal case |
| (the only case, for standard C). */ |
| for (block = block_stack; block != end_block; block = block->next) |
| if (block->data.block.stack_level != 0 |
| || block->data.block.cleanups != 0) |
| break; |
| |
| if (block != end_block) |
| { |
| /* Ok, a fixup is needed. Add a fixup to the list of such. */ |
| struct goto_fixup *fixup |
| = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup)); |
| /* In case an old stack level is restored, make sure that comes |
| after any pending stack adjust. */ |
| /* ?? If the fixup isn't to come at the present position, |
| doing the stack adjust here isn't useful. Doing it with our |
| settings at that location isn't useful either. Let's hope |
| someone does it! */ |
| if (last_insn == 0) |
| do_pending_stack_adjust (); |
| fixup->target = tree_label; |
| fixup->target_rtl = rtl_label; |
| |
| /* Create a BLOCK node and a corresponding matched set of |
| NOTE_INSN_BEGIN_BLOCK and NOTE_INSN_END_BLOCK notes at |
| this point. The notes will encapsulate any and all fixup |
| code which we might later insert at this point in the insn |
| stream. Also, the BLOCK node will be the parent (i.e. the |
| `SUPERBLOCK') of any other BLOCK nodes which we might create |
| later on when we are expanding the fixup code. */ |
| |
| { |
| register rtx original_before_jump |
| = last_insn ? last_insn : get_last_insn (); |
| |
| start_sequence (); |
| pushlevel (0); |
| fixup->before_jump = emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); |
| last_block_end_note = emit_note (NULL_PTR, NOTE_INSN_BLOCK_END); |
| fixup->context = poplevel (1, 0, 0); /* Create the BLOCK node now! */ |
| end_sequence (); |
| emit_insns_after (fixup->before_jump, original_before_jump); |
| } |
| |
| fixup->block_start_count = block_start_count; |
| fixup->stack_level = 0; |
| fixup->cleanup_list_list |
| = ((block->data.block.outer_cleanups |
| || block->data.block.cleanups) |
| ? tree_cons (NULL_TREE, block->data.block.cleanups, |
| block->data.block.outer_cleanups) |
| : 0); |
| fixup->next = goto_fixup_chain; |
| goto_fixup_chain = fixup; |
| } |
| |
| return block != 0; |
| } |
| |
| |
| /* Generate bytecode jump with OPCODE to a fixup routine that links to LABEL. |
| Make the fixup restore the stack level to STACK_LEVEL. */ |
| |
| static void |
| bc_expand_fixup (opcode, label, stack_level) |
| enum bytecode_opcode opcode; |
| struct bc_label *label; |
| int stack_level; |
| { |
| struct goto_fixup *fixup |
| = (struct goto_fixup *) oballoc (sizeof (struct goto_fixup)); |
| |
| fixup->label = bc_get_bytecode_label (); |
| fixup->bc_target = label; |
| fixup->bc_stack_level = stack_level; |
| fixup->bc_handled = FALSE; |
| |
| fixup->next = goto_fixup_chain; |
| goto_fixup_chain = fixup; |
| |
| /* Insert a jump to the fixup code */ |
| bc_emit_bytecode (opcode); |
| bc_emit_bytecode_labelref (fixup->label); |
| |
| #ifdef DEBUG_PRINT_CODE |
| fputc ('\n', stderr); |
| #endif |
| } |
| |
| /* Expand any needed fixups in the outputmost binding level of the |
| function. FIRST_INSN is the first insn in the function. */ |
| |
| void |
| expand_fixups (first_insn) |
| rtx first_insn; |
| { |
| fixup_gotos (NULL_PTR, NULL_RTX, NULL_TREE, first_insn, 0); |
| } |
| |
| /* When exiting a binding contour, process all pending gotos requiring fixups. |
| THISBLOCK is the structure that describes the block being exited. |
| STACK_LEVEL is the rtx for the stack level to restore exiting this contour. |
| CLEANUP_LIST is a list of expressions to evaluate on exiting this contour. |
| FIRST_INSN is the insn that began this contour. |
| |
| Gotos that jump out of this contour must restore the |
| stack level and do the cleanups before actually jumping. |
| |
| DONT_JUMP_IN nonzero means report error there is a jump into this |
| contour from before the beginning of the contour. |
| This is also done if STACK_LEVEL is nonzero. */ |
| |
| static void |
| fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in) |
| struct nesting *thisblock; |
| rtx stack_level; |
| tree cleanup_list; |
| rtx first_insn; |
| int dont_jump_in; |
| { |
| register struct goto_fixup *f, *prev; |
| |
| if (output_bytecode) |
| { |
| /* ??? The second arg is the bc stack level, which is not the same |
| as STACK_LEVEL. I have no idea what should go here, so I'll |
| just pass 0. */ |
| bc_fixup_gotos (thisblock, 0, cleanup_list, first_insn, dont_jump_in); |
| return; |
| } |
| |
| /* F is the fixup we are considering; PREV is the previous one. */ |
| /* We run this loop in two passes so that cleanups of exited blocks |
| are run first, and blocks that are exited are marked so |
| afterwards. */ |
| |
| for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) |
| { |
| /* Test for a fixup that is inactive because it is already handled. */ |
| if (f->before_jump == 0) |
| { |
| /* Delete inactive fixup from the chain, if that is easy to do. */ |
| if (prev != 0) |
| prev->next = f->next; |
| } |
| /* Has this fixup's target label been defined? |
| If so, we can finalize it. */ |
| else if (PREV_INSN (f->target_rtl) != 0) |
| { |
| register rtx cleanup_insns; |
| |
| /* Get the first non-label after the label |
| this goto jumps to. If that's before this scope begins, |
| we don't have a jump into the scope. */ |
| rtx after_label = f->target_rtl; |
| while (after_label != 0 && GET_CODE (after_label) == CODE_LABEL) |
| after_label = NEXT_INSN (after_label); |
| |
| /* If this fixup jumped into this contour from before the beginning |
| of this contour, report an error. */ |
| /* ??? Bug: this does not detect jumping in through intermediate |
| blocks that have stack levels or cleanups. |
| It detects only a problem with the innermost block |
| around the label. */ |
| if (f->target != 0 |
| && (dont_jump_in || stack_level || cleanup_list) |
| /* If AFTER_LABEL is 0, it means the jump goes to the end |
| of the rtl, which means it jumps into this scope. */ |
| && (after_label == 0 |
| || INSN_UID (first_insn) < INSN_UID (after_label)) |
| && INSN_UID (first_insn) > INSN_UID (f->before_jump) |
| && ! DECL_ERROR_ISSUED (f->target)) |
| { |
| error_with_decl (f->target, |
| "label `%s' used before containing binding contour"); |
| /* Prevent multiple errors for one label. */ |
| DECL_ERROR_ISSUED (f->target) = 1; |
| } |
| |
| /* We will expand the cleanups into a sequence of their own and |
| then later on we will attach this new sequence to the insn |
| stream just ahead of the actual jump insn. */ |
| |
| start_sequence (); |
| |
| /* Temporarily restore the lexical context where we will |
| logically be inserting the fixup code. We do this for the |
| sake of getting the debugging information right. */ |
| |
| pushlevel (0); |
| set_block (f->context); |
| |
| /* Expand the cleanups for blocks this jump exits. */ |
| if (f->cleanup_list_list) |
| { |
| tree lists; |
| for (lists = f->cleanup_list_list; lists; lists = TREE_CHAIN (lists)) |
| /* Marked elements correspond to blocks that have been closed. |
| Do their cleanups. */ |
| if (TREE_ADDRESSABLE (lists) |
| && TREE_VALUE (lists) != 0) |
| { |
| expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1); |
| /* Pop any pushes done in the cleanups, |
| in case function is about to return. */ |
| do_pending_stack_adjust (); |
| } |
| } |
| |
| /* Restore stack level for the biggest contour that this |
| jump jumps out of. */ |
| if (f->stack_level) |
| emit_stack_restore (SAVE_BLOCK, f->stack_level, f->before_jump); |
| |
| /* Finish up the sequence containing the insns which implement the |
| necessary cleanups, and then attach that whole sequence to the |
| insn stream just ahead of the actual jump insn. Attaching it |
| at that point insures that any cleanups which are in fact |
| implicit C++ object destructions (which must be executed upon |
| leaving the block) appear (to the debugger) to be taking place |
| in an area of the generated code where the object(s) being |
| destructed are still "in scope". */ |
| |
| cleanup_insns = get_insns (); |
| poplevel (1, 0, 0); |
| |
| end_sequence (); |
| emit_insns_after (cleanup_insns, f->before_jump); |
| |
| |
| f->before_jump = 0; |
| } |
| } |
| |
| /* For any still-undefined labels, do the cleanups for this block now. |
| We must do this now since items in the cleanup list may go out |
| of scope when the block ends. */ |
| for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) |
| if (f->before_jump != 0 |
| && PREV_INSN (f->target_rtl) == 0 |
| /* Label has still not appeared. If we are exiting a block with |
| a stack level to restore, that started before the fixup, |
| mark this stack level as needing restoration |
| when the fixup is later finalized. */ |
| && thisblock != 0 |
| /* Note: if THISBLOCK == 0 and we have a label that hasn't appeared, it |
| means the label is undefined. That's erroneous, but possible. */ |
| && (thisblock->data.block.block_start_count |
| <= f->block_start_count)) |
| { |
| tree lists = f->cleanup_list_list; |
| rtx cleanup_insns; |
| |
| for (; lists; lists = TREE_CHAIN (lists)) |
| /* If the following elt. corresponds to our containing block |
| then the elt. must be for this block. */ |
| if (TREE_CHAIN (lists) == thisblock->data.block.outer_cleanups) |
| { |
| start_sequence (); |
| pushlevel (0); |
| set_block (f->context); |
| expand_cleanups (TREE_VALUE (lists), NULL_TREE, 1, 1); |
| do_pending_stack_adjust (); |
| cleanup_insns = get_insns (); |
| poplevel (1, 0, 0); |
| end_sequence (); |
| if (cleanup_insns != 0) |
| f->before_jump |
| = emit_insns_after (cleanup_insns, f->before_jump); |
| |
| f->cleanup_list_list = TREE_CHAIN (lists); |
| } |
| |
| if (stack_level) |
| f->stack_level = stack_level; |
| } |
| } |
| |
| |
| /* When exiting a binding contour, process all pending gotos requiring fixups. |
| Note: STACK_DEPTH is not altered. |
| |
| The arguments are currently not used in the bytecode compiler, but we may |
| need them one day for languages other than C. |
| |
| THISBLOCK is the structure that describes the block being exited. |
| STACK_LEVEL is the rtx for the stack level to restore exiting this contour. |
| CLEANUP_LIST is a list of expressions to evaluate on exiting this contour. |
| FIRST_INSN is the insn that began this contour. |
| |
| Gotos that jump out of this contour must restore the |
| stack level and do the cleanups before actually jumping. |
| |
| DONT_JUMP_IN nonzero means report error there is a jump into this |
| contour from before the beginning of the contour. |
| This is also done if STACK_LEVEL is nonzero. */ |
| |
| static void |
| bc_fixup_gotos (thisblock, stack_level, cleanup_list, first_insn, dont_jump_in) |
| struct nesting *thisblock; |
| int stack_level; |
| tree cleanup_list; |
| rtx first_insn; |
| int dont_jump_in; |
| { |
| register struct goto_fixup *f, *prev; |
| int saved_stack_depth; |
| |
| /* F is the fixup we are considering; PREV is the previous one. */ |
| |
| for (prev = 0, f = goto_fixup_chain; f; prev = f, f = f->next) |
| { |
| /* Test for a fixup that is inactive because it is already handled. */ |
| if (f->before_jump == 0) |
| { |
| /* Delete inactive fixup from the chain, if that is easy to do. */ |
| if (prev) |
| prev->next = f->next; |
| } |
| |
| /* Emit code to restore the stack and continue */ |
| bc_emit_bytecode_labeldef (f->label); |
| |
| /* Save stack_depth across call, since bc_adjust_stack will alter |
| the perceived stack depth via the instructions generated. */ |
| |
| if (f->bc_stack_level >= 0) |
| { |
| saved_stack_depth = stack_depth; |
| bc_adjust_stack (stack_depth - f->bc_stack_level); |
| stack_depth = saved_stack_depth; |
| } |
| |
| bc_emit_bytecode (jump); |
| bc_emit_bytecode_labelref (f->bc_target); |
| |
| #ifdef DEBUG_PRINT_CODE |
| fputc ('\n', stderr); |
| #endif |
| } |
| |
| goto_fixup_chain = NULL; |
| } |
| |
| /* Generate RTL for an asm statement (explicit assembler code). |
| BODY is a STRING_CST node containing the assembler code text, |
| or an ADDR_EXPR containing a STRING_CST. */ |
| |
| void |
| expand_asm (body) |
| tree body; |
| { |
| if (output_bytecode) |
| { |
| error ("`asm' is invalid when generating bytecode"); |
| return; |
| } |
| |
| if (flag_check_memory_usage) |
| { |
| error ("`asm' cannot be used with `-fcheck-memory-usage'"); |
| return; |
| } |
| |
| if (TREE_CODE (body) == ADDR_EXPR) |
| body = TREE_OPERAND (body, 0); |
| |
| emit_insn (gen_rtx (ASM_INPUT, VOIDmode, |
| TREE_STRING_POINTER (body))); |
| last_expr_type = 0; |
| } |
| |
| /* Generate RTL for an asm statement with arguments. |
| STRING is the instruction template. |
| OUTPUTS is a list of output arguments (lvalues); INPUTS a list of inputs. |
| Each output or input has an expression in the TREE_VALUE and |
| a constraint-string in the TREE_PURPOSE. |
| CLOBBERS is a list of STRING_CST nodes each naming a hard register |
| that is clobbered by this insn. |
| |
| Not all kinds of lvalue that may appear in OUTPUTS can be stored directly. |
| Some elements of OUTPUTS may be replaced with trees representing temporary |
| values. The caller should copy those temporary values to the originally |
| specified lvalues. |
| |
| VOL nonzero means the insn is volatile; don't optimize it. */ |
| |
| void |
| expand_asm_operands (string, outputs, inputs, clobbers, vol, filename, line) |
| tree string, outputs, inputs, clobbers; |
| int vol; |
| char *filename; |
| int line; |
| { |
| rtvec argvec, constraints; |
| rtx body; |
| int ninputs = list_length (inputs); |
| int noutputs = list_length (outputs); |
| int ninout = 0; |
| int nclobbers; |
| tree tail; |
| register int i; |
| /* Vector of RTX's of evaluated output operands. */ |
| rtx *output_rtx = (rtx *) alloca (noutputs * sizeof (rtx)); |
| int *inout_opnum = (int *) alloca (noutputs * sizeof (int)); |
| enum machine_mode *inout_mode |
| = (enum machine_mode *) alloca (noutputs * sizeof (enum machine_mode)); |
| /* The insn we have emitted. */ |
| rtx insn; |
| |
| /* An ASM with no outputs needs to be treated as volatile. */ |
| if (noutputs == 0) |
| vol = 1; |
| |
| if (output_bytecode) |
| { |
| error ("`asm' is invalid when generating bytecode"); |
| return; |
| } |
| |
| if (flag_check_memory_usage) |
| { |
| error ("`asm' cannot be used with `-fcheck-memory-usage'"); |
| return; |
| } |
| |
| /* Count the number of meaningful clobbered registers, ignoring what |
| we would ignore later. */ |
| nclobbers = 0; |
| for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
| { |
| char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); |
| i = decode_reg_name (regname); |
| if (i >= 0 || i == -4) |
| ++nclobbers; |
| else if (i == -2) |
| error ("unknown register name `%s' in `asm'", regname); |
| } |
| |
| last_expr_type = 0; |
| |
| for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
| { |
| tree val = TREE_VALUE (tail); |
| tree type = TREE_TYPE (val); |
| tree val1; |
| int j; |
| int found_equal = 0; |
| int found_plus = 0; |
| int allows_reg = 0; |
| |
| /* If there's an erroneous arg, emit no insn. */ |
| if (TREE_TYPE (val) == error_mark_node) |
| return; |
| |
| /* Make sure constraint has `=' and does not have `+'. Also, see |
| if it allows any register. Be liberal on the latter test, since |
| the worst that happens if we get it wrong is we issue an error |
| message. */ |
| |
| for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++) |
| switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]) |
| { |
| case '+': |
| /* Make sure we can specify the matching operand. */ |
| if (i > 9) |
| { |
| error ("output operand constraint %d contains `+'", i); |
| return; |
| } |
| |
| /* Replace '+' with '='. */ |
| TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] = '='; |
| found_plus = 1; |
| break; |
| |
| case '=': |
| found_equal = 1; |
| break; |
| |
| case '?': case '!': case '*': case '%': case '&': |
| case 'V': case 'm': case 'o': case '<': case '>': |
| case 'E': case 'F': case 'G': case 'H': case 'X': |
| case 's': case 'i': case 'n': |
| case 'I': case 'J': case 'K': case 'L': case 'M': |
| case 'N': case 'O': case 'P': case ',': |
| #ifdef EXTRA_CONSTRAINT |
| case 'Q': case 'R': case 'S': case 'T': case 'U': |
| #endif |
| break; |
| |
| case '0': case '1': case '2': case '3': case '4': |
| case '5': case '6': case '7': case '8': case '9': |
| error ("matching constraint not valid in output operand"); |
| break; |
| |
| case 'p': case 'g': case 'r': |
| default: |
| allows_reg = 1; |
| break; |
| } |
| |
| if (! found_equal && ! found_plus) |
| { |
| error ("output operand constraint lacks `='"); |
| return; |
| } |
| |
| /* If an output operand is not a decl or indirect ref and our constraint |
| allows a register, make a temporary to act as an intermediate. |
| Make the asm insn write into that, then our caller will copy it to |
| the real output operand. Likewise for promoted variables. */ |
| |
| if (TREE_CODE (val) == INDIRECT_REF |
| || (TREE_CODE_CLASS (TREE_CODE (val)) == 'd' |
| && ! (GET_CODE (DECL_RTL (val)) == REG |
| && GET_MODE (DECL_RTL (val)) != TYPE_MODE (type))) |
| || ! allows_reg |
| || found_plus) |
| { |
| if (! allows_reg) |
| mark_addressable (TREE_VALUE (tail)); |
| |
| output_rtx[i] |
| = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, |
| EXPAND_MEMORY_USE_WO); |
| |
| if (! allows_reg && GET_CODE (output_rtx[i]) != MEM) |
| error ("output number %d not directly addressable", i); |
| } |
| else |
| { |
| output_rtx[i] = assign_temp (type, 0, 0, 0); |
| TREE_VALUE (tail) = make_tree (type, output_rtx[i]); |
| } |
| |
| if (found_plus) |
| { |
| inout_mode[ninout] = TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))); |
| inout_opnum[ninout++] = i; |
| } |
| } |
| |
| ninputs += ninout; |
| if (ninputs + noutputs > MAX_RECOG_OPERANDS) |
| { |
| error ("more than %d operands in `asm'", MAX_RECOG_OPERANDS); |
| return; |
| } |
| |
| /* Make vectors for the expression-rtx and constraint strings. */ |
| |
| argvec = rtvec_alloc (ninputs); |
| constraints = rtvec_alloc (ninputs); |
| |
| body = gen_rtx (ASM_OPERANDS, VOIDmode, |
| TREE_STRING_POINTER (string), "", 0, argvec, constraints, |
| filename, line); |
| MEM_VOLATILE_P (body) = vol; |
| |
| /* Eval the inputs and put them into ARGVEC. |
| Put their constraints into ASM_INPUTs and store in CONSTRAINTS. */ |
| |
| i = 0; |
| for (tail = inputs; tail; tail = TREE_CHAIN (tail)) |
| { |
| int j; |
| int allows_reg = 0; |
| |
| /* If there's an erroneous arg, emit no insn, |
| because the ASM_INPUT would get VOIDmode |
| and that could cause a crash in reload. */ |
| if (TREE_TYPE (TREE_VALUE (tail)) == error_mark_node) |
| return; |
| if (TREE_PURPOSE (tail) == NULL_TREE) |
| { |
| error ("hard register `%s' listed as input operand to `asm'", |
| TREE_STRING_POINTER (TREE_VALUE (tail)) ); |
| return; |
| } |
| |
| /* Make sure constraint has neither `=' nor `+'. */ |
| |
| for (j = 0; j < TREE_STRING_LENGTH (TREE_PURPOSE (tail)) - 1; j++) |
| switch (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]) |
| { |
| case '+': case '=': |
| error ("input operand constraint contains `%c'", |
| TREE_STRING_POINTER (TREE_PURPOSE (tail))[j]); |
| return; |
| |
| case '?': case '!': case '*': case '%': case '&': |
| case 'V': case 'm': case 'o': case '<': case '>': |
| case 'E': case 'F': case 'G': case 'H': case 'X': |
| case 's': case 'i': case 'n': |
| case 'I': case 'J': case 'K': case 'L': case 'M': |
| case 'N': case 'O': case 'P': case ',': |
| #ifdef EXTRA_CONSTRAINT |
| case 'Q': case 'R': case 'S': case 'T': case 'U': |
| #endif |
| break; |
| |
| /* Whether or not a numeric constraint allows a register is |
| decided by the matching constraint, and so there is no need |
| to do anything special with them. We must handle them in |
| the default case, so that we don't unnecessarily force |
| operands to memory. */ |
| case '0': case '1': case '2': case '3': case '4': |
| case '5': case '6': case '7': case '8': case '9': |
| if (TREE_STRING_POINTER (TREE_PURPOSE (tail))[j] |
| >= '0' + noutputs) |
| error ("matching constraint references invalid operand number"); |
| |
| /* ... fall through ... */ |
| |
| case 'p': case 'g': case 'r': |
| default: |
| allows_reg = 1; |
| break; |
| } |
| |
| if (! allows_reg) |
| mark_addressable (TREE_VALUE (tail)); |
| |
| XVECEXP (body, 3, i) /* argvec */ |
| = expand_expr (TREE_VALUE (tail), NULL_RTX, VOIDmode, 0); |
| if (CONSTANT_P (XVECEXP (body, 3, i)) |
| && ! general_operand (XVECEXP (body, 3, i), |
| TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))))) |
| { |
| if (allows_reg) |
| XVECEXP (body, 3, i) |
| = force_reg (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), |
| XVECEXP (body, 3, i)); |
| else |
| XVECEXP (body, 3, i) |
| = force_const_mem (TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), |
| XVECEXP (body, 3, i)); |
| } |
| |
| if (! allows_reg |
| && (GET_CODE (XVECEXP (body, 3, i)) == REG |
| || GET_CODE (XVECEXP (body, 3, i)) == SUBREG |
| || GET_CODE (XVECEXP (body, 3, i)) == CONCAT)) |
| { |
| tree type = TREE_TYPE (TREE_VALUE (tail)); |
| rtx memloc = assign_temp (type, 1, 1, 1); |
| |
| emit_move_insn (memloc, XVECEXP (body, 3, i)); |
| XVECEXP (body, 3, i) = memloc; |
| } |
| |
| XVECEXP (body, 4, i) /* constraints */ |
| = gen_rtx (ASM_INPUT, TYPE_MODE (TREE_TYPE (TREE_VALUE (tail))), |
| TREE_STRING_POINTER (TREE_PURPOSE (tail))); |
| i++; |
| } |
| |
| /* Protect all the operands from the queue, |
| now that they have all been evaluated. */ |
| |
| for (i = 0; i < ninputs - ninout; i++) |
| XVECEXP (body, 3, i) = protect_from_queue (XVECEXP (body, 3, i), 0); |
| |
| for (i = 0; i < noutputs; i++) |
| output_rtx[i] = protect_from_queue (output_rtx[i], 1); |
| |
| /* For in-out operands, copy output rtx to input rtx. */ |
| for (i = 0; i < ninout; i++) |
| { |
| static char match[9+1][2] |
| = {"0", "1", "2", "3", "4", "5", "6", "7", "8", "9"}; |
| int j = inout_opnum[i]; |
| |
| XVECEXP (body, 3, ninputs - ninout + i) /* argvec */ |
| = output_rtx[j]; |
| XVECEXP (body, 4, ninputs - ninout + i) /* constraints */ |
| = gen_rtx (ASM_INPUT, inout_mode[j], match[j]); |
| } |
| |
| /* Now, for each output, construct an rtx |
| (set OUTPUT (asm_operands INSN OUTPUTNUMBER OUTPUTCONSTRAINT |
| ARGVEC CONSTRAINTS)) |
| If there is more than one, put them inside a PARALLEL. */ |
| |
| if (noutputs == 1 && nclobbers == 0) |
| { |
| XSTR (body, 1) = TREE_STRING_POINTER (TREE_PURPOSE (outputs)); |
| insn = emit_insn (gen_rtx (SET, VOIDmode, output_rtx[0], body)); |
| } |
| else if (noutputs == 0 && nclobbers == 0) |
| { |
| /* No output operands: put in a raw ASM_OPERANDS rtx. */ |
| insn = emit_insn (body); |
| } |
| else |
| { |
| rtx obody = body; |
| int num = noutputs; |
| if (num == 0) num = 1; |
| body = gen_rtx (PARALLEL, VOIDmode, rtvec_alloc (num + nclobbers)); |
| |
| /* For each output operand, store a SET. */ |
| |
| for (i = 0, tail = outputs; tail; tail = TREE_CHAIN (tail), i++) |
| { |
| XVECEXP (body, 0, i) |
| = gen_rtx (SET, VOIDmode, |
| output_rtx[i], |
| gen_rtx (ASM_OPERANDS, VOIDmode, |
| TREE_STRING_POINTER (string), |
| TREE_STRING_POINTER (TREE_PURPOSE (tail)), |
| i, argvec, constraints, |
| filename, line)); |
| MEM_VOLATILE_P (SET_SRC (XVECEXP (body, 0, i))) = vol; |
| } |
| |
| /* If there are no outputs (but there are some clobbers) |
| store the bare ASM_OPERANDS into the PARALLEL. */ |
| |
| if (i == 0) |
| XVECEXP (body, 0, i++) = obody; |
| |
| /* Store (clobber REG) for each clobbered register specified. */ |
| |
| for (tail = clobbers; tail; tail = TREE_CHAIN (tail)) |
| { |
| char *regname = TREE_STRING_POINTER (TREE_VALUE (tail)); |
| int j = decode_reg_name (regname); |
| |
| if (j < 0) |
| { |
| if (j == -3) /* `cc', which is not a register */ |
| continue; |
| |
| if (j == -4) /* `memory', don't cache memory across asm */ |
| { |
| XVECEXP (body, 0, i++) |
| = gen_rtx (CLOBBER, VOIDmode, |
| gen_rtx (MEM, BLKmode, |
| gen_rtx (SCRATCH, VOIDmode, 0))); |
| continue; |
| } |
| |
| /* Ignore unknown register, error already signalled. */ |
| continue; |
| } |
| |
| /* Use QImode since that's guaranteed to clobber just one reg. */ |
| XVECEXP (body, 0, i++) |
| = gen_rtx (CLOBBER, VOIDmode, gen_rtx (REG, QImode, j)); |
| } |
| |
| insn = emit_insn (body); |
| } |
| |
| free_temp_slots (); |
| } |
| |
| /* Generate RTL to evaluate the expression EXP |
| and remember it in case this is the VALUE in a ({... VALUE; }) constr. */ |
| |
| void |
| expand_expr_stmt (exp) |
| tree exp; |
| { |
| if (output_bytecode) |
| { |
| int org_stack_depth = stack_depth; |
| |
| bc_expand_expr (exp); |
| |
| /* Restore stack depth */ |
| if (stack_depth < org_stack_depth) |
| abort (); |
| |
| bc_emit_instruction (drop); |
| |
| last_expr_type = TREE_TYPE (exp); |
| return; |
| } |
| |
| /* If -W, warn about statements with no side effects, |
| except for an explicit cast to void (e.g. for assert()), and |
| except inside a ({...}) where they may be useful. */ |
| if (expr_stmts_for_value == 0 && exp != error_mark_node) |
| { |
| if (! TREE_SIDE_EFFECTS (exp) && (extra_warnings || warn_unused) |
| && !(TREE_CODE (exp) == CONVERT_EXPR |
| && TREE_TYPE (exp) == void_type_node)) |
| warning_with_file_and_line (emit_filename, emit_lineno, |
| "statement with no effect"); |
| else if (warn_unused) |
| warn_if_unused_value (exp); |
| } |
| |
| /* If EXP is of function type and we are expanding statements for |
| value, convert it to pointer-to-function. */ |
| if (expr_stmts_for_value && TREE_CODE (TREE_TYPE (exp)) == FUNCTION_TYPE) |
| exp = build1 (ADDR_EXPR, build_pointer_type (TREE_TYPE (exp)), exp); |
| |
| last_expr_type = TREE_TYPE (exp); |
| if (! flag_syntax_only) |
| last_expr_value = expand_expr (exp, |
| (expr_stmts_for_value |
| ? NULL_RTX : const0_rtx), |
| VOIDmode, 0); |
| |
| /* If all we do is reference a volatile value in memory, |
| copy it to a register to be sure it is actually touched. */ |
| if (last_expr_value != 0 && GET_CODE (last_expr_value) == MEM |
| && TREE_THIS_VOLATILE (exp)) |
| { |
| if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode) |
| ; |
| else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode) |
| copy_to_reg (last_expr_value); |
| else |
| { |
| rtx lab = gen_label_rtx (); |
| |
| /* Compare the value with itself to reference it. */ |
| emit_cmp_insn (last_expr_value, last_expr_value, EQ, |
| expand_expr (TYPE_SIZE (last_expr_type), |
| NULL_RTX, VOIDmode, 0), |
| BLKmode, 0, |
| TYPE_ALIGN (last_expr_type) / BITS_PER_UNIT); |
| emit_jump_insn ((*bcc_gen_fctn[(int) EQ]) (lab)); |
| emit_label (lab); |
| } |
| } |
| |
| /* If this expression is part of a ({...}) and is in memory, we may have |
| to preserve temporaries. */ |
| preserve_temp_slots (last_expr_value); |
| |
| /* Free any temporaries used to evaluate this expression. Any temporary |
| used as a result of this expression will already have been preserved |
| above. */ |
| free_temp_slots (); |
| |
| emit_queue (); |
| } |
| |
| /* Warn if EXP contains any computations whose results are not used. |
| Return 1 if a warning is printed; 0 otherwise. */ |
| |
| int |
| warn_if_unused_value (exp) |
| tree exp; |
| { |
| if (TREE_USED (exp)) |
| return 0; |
| |
| switch (TREE_CODE (exp)) |
| { |
| case PREINCREMENT_EXPR: |
| case POSTINCREMENT_EXPR: |
| case PREDECREMENT_EXPR: |
| case POSTDECREMENT_EXPR: |
| case MODIFY_EXPR: |
| case INIT_EXPR: |
| case TARGET_EXPR: |
| case CALL_EXPR: |
| case METHOD_CALL_EXPR: |
| case RTL_EXPR: |
| case TRY_CATCH_EXPR: |
| case WITH_CLEANUP_EXPR: |
| case EXIT_EXPR: |
| /* We don't warn about COND_EXPR because it may be a useful |
| construct if either arm contains a side effect. */ |
| case COND_EXPR: |
| return 0; |
| |
| case BIND_EXPR: |
| /* For a binding, warn if no side effect within it. */ |
| return warn_if_unused_value (TREE_OPERAND (exp, 1)); |
| |
| case SAVE_EXPR: |
| return warn_if_unused_value (TREE_OPERAND (exp, 1)); |
| |
| case TRUTH_ORIF_EXPR: |
| case TRUTH_ANDIF_EXPR: |
| /* In && or ||, warn if 2nd operand has no side effect. */ |
| return warn_if_unused_value (TREE_OPERAND (exp, 1)); |
| |
| case COMPOUND_EXPR: |
| if (TREE_NO_UNUSED_WARNING (exp)) |
| return 0; |
| if (warn_if_unused_value (TREE_OPERAND (exp, 0))) |
| return 1; |
| /* Let people do `(foo (), 0)' without a warning. */ |
| if (TREE_CONSTANT (TREE_OPERAND (exp, 1))) |
| return 0; |
| return warn_if_unused_value (TREE_OPERAND (exp, 1)); |
| |
| case NOP_EXPR: |
| case CONVERT_EXPR: |
| case NON_LVALUE_EXPR: |
| /* Don't warn about values cast to void. */ |
| if (TREE_TYPE (exp) == void_type_node) |
| return 0; |
| /* Don't warn about conversions not explicit in the user's program. */ |
| if (TREE_NO_UNUSED_WARNING (exp)) |
| return 0; |
| /* Assignment to a cast usually results in a cast of a modify. |
| Don't complain about that. There can be an arbitrary number of |
| casts before the modify, so we must loop until we find the first |
| non-cast expression and then test to see if that is a modify. */ |
| { |
| tree tem = TREE_OPERAND (exp, 0); |
| |
| while (TREE_CODE (tem) == CONVERT_EXPR || TREE_CODE (tem) == NOP_EXPR) |
| tem = TREE_OPERAND (tem, 0); |
| |
| if (TREE_CODE (tem) == MODIFY_EXPR || TREE_CODE (tem) == INIT_EXPR |
| || TREE_CODE (tem) == CALL_EXPR) |
| return 0; |
| } |
| goto warn; |
| |
| case INDIRECT_REF: |
| /* Don't warn about automatic dereferencing of references, since |
| the user cannot control it. */ |
| if (TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == REFERENCE_TYPE) |
| return warn_if_unused_value (TREE_OPERAND (exp, 0)); |
| /* ... fall through ... */ |
| |
| default: |
| /* Referencing a volatile value is a side effect, so don't warn. */ |
| if ((TREE_CODE_CLASS (TREE_CODE (exp)) == 'd' |
| || TREE_CODE_CLASS (TREE_CODE (exp)) == 'r') |
| && TREE_THIS_VOLATILE (exp)) |
| return 0; |
| warn: |
| warning_with_file_and_line (emit_filename, emit_lineno, |
| "value computed is not used"); |
| return 1; |
| } |
| } |
| |
| /* Clear out the memory of the last expression evaluated. */ |
| |
| void |
| clear_last_expr () |
| { |
| last_expr_type = 0; |
| } |
| |
| /* Begin a statement which will return a value. |
| Return the RTL_EXPR for this statement expr. |
| The caller must save that value and pass it to expand_end_stmt_expr. */ |
| |
| tree |
| expand_start_stmt_expr () |
| { |
| int momentary; |
| tree t; |
| |
| /* When generating bytecode just note down the stack depth */ |
| if (output_bytecode) |
| return (build_int_2 (stack_depth, 0)); |
| |
| /* Make the RTL_EXPR node temporary, not momentary, |
| so that rtl_expr_chain doesn't become garbage. */ |
| momentary = suspend_momentary (); |
| t = make_node (RTL_EXPR); |
| resume_momentary (momentary); |
| do_pending_stack_adjust (); |
| start_sequence_for_rtl_expr (t); |
| NO_DEFER_POP; |
| expr_stmts_for_value++; |
| return t; |
| } |
| |
| /* Restore the previous state at the end of a statement that returns a value. |
| Returns a tree node representing the statement's value and the |
| insns to compute the value. |
| |
| The nodes of that expression have been freed by now, so we cannot use them. |
| But we don't want to do that anyway; the expression has already been |
| evaluated and now we just want to use the value. So generate a RTL_EXPR |
| with the proper type and RTL value. |
| |
| If the last substatement was not an expression, |
| return something with type `void'. */ |
| |
| tree |
| expand_end_stmt_expr (t) |
| tree t; |
| { |
| if (output_bytecode) |
| { |
| int i; |
| tree t; |
| |
| |
| /* At this point, all expressions have been evaluated in order. |
| However, all expression values have been popped when evaluated, |
| which means we have to recover the last expression value. This is |
| the last value removed by means of a `drop' instruction. Instead |
| of adding code to inhibit dropping the last expression value, it |
| is here recovered by undoing the `drop'. Since `drop' is |
| equivalent to `adjustackSI [1]', it can be undone with `adjstackSI |
| [-1]'. */ |
| |
| bc_adjust_stack (-1); |
| |
| if (!last_expr_type) |
| last_expr_type = void_type_node; |
| |
| t = make_node (RTL_EXPR); |
| TREE_TYPE (t) = last_expr_type; |
| RTL_EXPR_RTL (t) = NULL; |
| RTL_EXPR_SEQUENCE (t) = NULL; |
| |
| /* Don't consider deleting this expr or containing exprs at tree level. */ |
| TREE_THIS_VOLATILE (t) = 1; |
| |
| last_expr_type = 0; |
| return t; |
| } |
| |
| OK_DEFER_POP; |
| |
| if (last_expr_type == 0) |
| { |
| last_expr_type = void_type_node; |
| last_expr_value = const0_rtx; |
| } |
| else if (last_expr_value == 0) |
| /* There are some cases where this can happen, such as when the |
| statement is void type. */ |
| last_expr_value = const0_rtx; |
| else if (GET_CODE (last_expr_value) != REG && ! CONSTANT_P (last_expr_value)) |
| /* Remove any possible QUEUED. */ |
| last_expr_value = protect_from_queue (last_expr_value, 0); |
| |
| emit_queue (); |
| |
| TREE_TYPE (t) = last_expr_type; |
| RTL_EXPR_RTL (t) = last_expr_value; |
| RTL_EXPR_SEQUENCE (t) = get_insns (); |
| |
| rtl_expr_chain = tree_cons (NULL_TREE, t, rtl_expr_chain); |
| |
| end_sequence (); |
| |
| /* Don't consider deleting this expr or containing exprs at tree level. */ |
| TREE_SIDE_EFFECTS (t) = 1; |
| /* Propagate volatility of the actual RTL expr. */ |
| TREE_THIS_VOLATILE (t) = volatile_refs_p (last_expr_value); |
| |
| last_expr_type = 0; |
| expr_stmts_for_value--; |
| |
| return t; |
| } |
| |
| /* Generate RTL for the start of an if-then. COND is the expression |
| whose truth should be tested. |
| |
| If EXITFLAG is nonzero, this conditional is visible to |
| `exit_something'. */ |
| |
| void |
| expand_start_cond (cond, exitflag) |
| tree cond; |
| int exitflag; |
| { |
| struct nesting *thiscond = ALLOC_NESTING (); |
| |
| /* Make an entry on cond_stack for the cond we are entering. */ |
| |
| thiscond->next = cond_stack; |
| thiscond->all = nesting_stack; |
| thiscond->depth = ++nesting_depth; |
| thiscond->data.cond.next_label = gen_label_rtx (); |
| /* Before we encounter an `else', we don't need a separate exit label |
| unless there are supposed to be exit statements |
| to exit this conditional. */ |
| thiscond->exit_label = exitflag ? gen_label_rtx () : 0; |
| thiscond->data.cond.endif_label = thiscond->exit_label; |
| cond_stack = thiscond; |
| nesting_stack = thiscond; |
| |
| if (output_bytecode) |
| bc_expand_start_cond (cond, exitflag); |
| else |
| do_jump (cond, thiscond->data.cond.next_label, NULL_RTX); |
| } |
| |
| /* Generate RTL between then-clause and the elseif-clause |
| of an if-then-elseif-.... */ |
| |
| void |
| expand_start_elseif (cond) |
| tree cond; |
| { |
| if (cond_stack->data.cond.endif_label == 0) |
| cond_stack->data.cond.endif_label = gen_label_rtx (); |
| emit_jump (cond_stack->data.cond.endif_label); |
| emit_label (cond_stack->data.cond.next_label); |
| cond_stack->data.cond.next_label = gen_label_rtx (); |
| do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); |
| } |
| |
| /* Generate RTL between the then-clause and the else-clause |
| of an if-then-else. */ |
| |
| void |
| expand_start_else () |
| { |
| if (cond_stack->data.cond.endif_label == 0) |
| cond_stack->data.cond.endif_label = gen_label_rtx (); |
| |
| if (output_bytecode) |
| { |
| bc_expand_start_else (); |
| return; |
| } |
| |
| emit_jump (cond_stack->data.cond.endif_label); |
| emit_label (cond_stack->data.cond.next_label); |
| cond_stack->data.cond.next_label = 0; /* No more _else or _elseif calls. */ |
| } |
| |
| /* After calling expand_start_else, turn this "else" into an "else if" |
| by providing another condition. */ |
| |
| void |
| expand_elseif (cond) |
| tree cond; |
| { |
| cond_stack->data.cond.next_label = gen_label_rtx (); |
| do_jump (cond, cond_stack->data.cond.next_label, NULL_RTX); |
| } |
| |
| /* Generate RTL for the end of an if-then. |
| Pop the record for it off of cond_stack. */ |
| |
| void |
| expand_end_cond () |
| { |
| struct nesting *thiscond = cond_stack; |
| |
| if (output_bytecode) |
| bc_expand_end_cond (); |
| else |
| { |
| do_pending_stack_adjust (); |
| if (thiscond->data.cond.next_label) |
| emit_label (thiscond->data.cond.next_label); |
| if (thiscond->data.cond.endif_label) |
| emit_label (thiscond->data.cond.endif_label); |
| } |
| |
| POPSTACK (cond_stack); |
| last_expr_type = 0; |
| } |
| |
| |
| /* Generate code for the start of an if-then. COND is the expression |
| whose truth is to be tested; if EXITFLAG is nonzero this conditional |
| is to be visible to exit_something. It is assumed that the caller |
| has pushed the previous context on the cond stack. */ |
| |
| static void |
| bc_expand_start_cond (cond, exitflag) |
| tree cond; |
| int exitflag; |
| { |
| struct nesting *thiscond = cond_stack; |
| |
| thiscond->data.case_stmt.nominal_type = cond; |
| if (! exitflag) |
| thiscond->exit_label = gen_label_rtx (); |
| bc_expand_expr (cond); |
| bc_emit_bytecode (xjumpifnot); |
| bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label)); |
| |
| #ifdef DEBUG_PRINT_CODE |
| fputc ('\n', stderr); |
| #endif |
| } |
| |
| /* Generate the label for the end of an if with |
| no else- clause. */ |
| |
| static void |
| bc_expand_end_cond () |
| { |
| struct nesting *thiscond = cond_stack; |
| |
| bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->exit_label)); |
| } |
| |
| /* Generate code for the start of the else- clause of |
| an if-then-else. */ |
| |
| static void |
| bc_expand_start_else () |
| { |
| struct nesting *thiscond = cond_stack; |
| |
| thiscond->data.cond.endif_label = thiscond->exit_label; |
| thiscond->exit_label = gen_label_rtx (); |
| bc_emit_bytecode (jump); |
| bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thiscond->exit_label)); |
| |
| #ifdef DEBUG_PRINT_CODE |
| fputc ('\n', stderr); |
| #endif |
| |
| bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thiscond->data.cond.endif_label)); |
| } |
| |
| /* Generate RTL for the start of a loop. EXIT_FLAG is nonzero if this |
| loop should be exited by `exit_something'. This is a loop for which |
| `expand_continue' will jump to the top of the loop. |
| |
| Make an entry on loop_stack to record the labels associated with |
| this loop. */ |
| |
| struct nesting * |
| expand_start_loop (exit_flag) |
| int exit_flag; |
| { |
| register struct nesting *thisloop = ALLOC_NESTING (); |
| |
| /* Make an entry on loop_stack for the loop we are entering. */ |
| |
| thisloop->next = loop_stack; |
| thisloop->all = nesting_stack; |
| thisloop->depth = ++nesting_depth; |
| thisloop->data.loop.start_label = gen_label_rtx (); |
| thisloop->data.loop.end_label = gen_label_rtx (); |
| thisloop->data.loop.alt_end_label = 0; |
| thisloop->data.loop.continue_label = thisloop->data.loop.start_label; |
| thisloop->exit_label = exit_flag ? thisloop->data.loop.end_label : 0; |
| loop_stack = thisloop; |
| nesting_stack = thisloop; |
| |
| if (output_bytecode) |
| { |
| bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->data.loop.start_label)); |
| return thisloop; |
| } |
| |
| do_pending_stack_adjust (); |
| emit_queue (); |
| emit_note (NULL_PTR, NOTE_INSN_LOOP_BEG); |
| emit_label (thisloop->data.loop.start_label); |
| |
| return thisloop; |
| } |
| |
| /* Like expand_start_loop but for a loop where the continuation point |
| (for expand_continue_loop) will be specified explicitly. */ |
| |
| struct nesting * |
| expand_start_loop_continue_elsewhere (exit_flag) |
| int exit_flag; |
| { |
| struct nesting *thisloop = expand_start_loop (exit_flag); |
| loop_stack->data.loop.continue_label = gen_label_rtx (); |
| return thisloop; |
| } |
| |
| /* Specify the continuation point for a loop started with |
| expand_start_loop_continue_elsewhere. |
| Use this at the point in the code to which a continue statement |
| should jump. */ |
| |
| void |
| expand_loop_continue_here () |
| { |
| if (output_bytecode) |
| { |
| bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (loop_stack->data.loop.continue_label)); |
| return; |
| } |
| do_pending_stack_adjust (); |
| emit_note (NULL_PTR, NOTE_INSN_LOOP_CONT); |
| emit_label (loop_stack->data.loop.continue_label); |
| } |
| |
| /* End a loop. */ |
| |
| static void |
| bc_expand_end_loop () |
| { |
| struct nesting *thisloop = loop_stack; |
| |
| bc_emit_bytecode (jump); |
| bc_emit_bytecode_labelref (BYTECODE_BC_LABEL (thisloop->data.loop.start_label)); |
| |
| #ifdef DEBUG_PRINT_CODE |
| fputc ('\n', stderr); |
| #endif |
| |
| bc_emit_bytecode_labeldef (BYTECODE_BC_LABEL (thisloop->exit_label)); |
| POPSTACK (loop_stack); |
| last_expr_type = 0; |
| } |
| |
| |
| /* Finish a loop. Generate a jump back to the top and the loop-exit label. |
| Pop the block off of loop_stack. */ |
| |
| void |
| expand_end_loop () |
| { |
| register rtx insn; |
| register rtx start_label; |
| rtx last_test_insn = 0; |
| int num_insns = 0; |
| |
| if (output_bytecode) |
| { |
| bc_expand_end_loop (); |
| return; |
| } |
| |
| insn = get_last_insn (); |
| start_label = loop_stack->data.loop.start_label; |
| |
| /* Mark the continue-point at the top of the loop if none elsewhere. */ |
| if (start_label == loop_stack->data.loop.continue_label) |
| emit_note_before (NOTE_INSN_LOOP_CONT, start_label); |
| |
| do_pending_stack_adjust (); |
| |
| /* If optimizing, perhaps reorder the loop. If the loop |
| starts with a conditional exit, roll that to the end |
| where it will optimize together with the jump back. |
| |
| We look for the last conditional branch to the exit that we encounter |
| before hitting 30 insns or a CALL_INSN. If we see an unconditional |
| branch to the exit first, use it. |
| |
| We must also stop at NOTE_INSN_BLOCK_BEG and NOTE_INSN_BLOCK_END notes |
| because moving them is not valid. */ |
| |
| if (optimize |
| && |
| ! (GET_CODE (insn) == JUMP_INSN |
| && GET_CODE (PATTERN (insn)) == SET |
| && SET_DEST (PATTERN (insn)) == pc_rtx |
| && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE)) |
| { |
| /* Scan insns from the top of the loop looking for a qualified |
| conditional exit. */ |
| for (insn = NEXT_INSN (loop_stack->data.loop.start_label); insn; |
| insn = NEXT_INSN (insn)) |
| { |
| if (GET_CODE (insn) == CALL_INSN || GET_CODE (insn) == CODE_LABEL) |
| break; |
| |
| if (GET_CODE (insn) == NOTE |
| && (NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_BEG |
| || NOTE_LINE_NUMBER (insn) == NOTE_INSN_BLOCK_END)) |
| break; |
| |
| if (GET_CODE (insn) == JUMP_INSN || GET_CODE (insn) == INSN) |
| num_insns++; |
| |
| if (last_test_insn && num_insns > 30) |
| break; |
| |
| if (GET_CODE (insn) == JUMP_INSN && GET_CODE (PATTERN (insn)) == SET |
| && SET_DEST (PATTERN (insn)) == pc_rtx |
| && GET_CODE (SET_SRC (PATTERN (insn))) == IF_THEN_ELSE |
| && ((GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 1)) == LABEL_REF |
| && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0) |
| == loop_stack->data.loop.end_label) |
| || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 1), 0) |
| == loop_stack->data.loop.alt_end_label))) |
| || (GET_CODE (XEXP (SET_SRC (PATTERN (insn)), 2)) == LABEL_REF |
| && ((XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0) |
| == loop_stack->data.loop.end_label) |
| || (XEXP (XEXP (SET_SRC (PATTERN (insn)), 2), 0) |
| == loop_stack->data.loop.alt_end_label))))) |
| last_test_insn = insn; |
| |
| if (last_test_insn == 0 && GET_CODE (insn) == JUMP_INSN |
| && GET_CODE (PATTERN (insn)) == SET |
| && SET_DEST (PATTERN (insn)) == pc_rtx |
| && GET_CODE (SET_SRC (PATTERN (insn))) == LABEL_REF |
| && ((XEXP (SET_SRC (PATTERN (insn)), 0) |
| == loop_stack->data.loop.end_label) |
| || (XEXP (SET_SRC (PATTERN (insn)), 0) |
| == loop_stack->data.loop.alt_end_label))) |
| /* Include BARRIER. */ |
| last_test_insn = NEXT_INSN (insn); |
| } |
| |
| if (last_test_insn != 0 && last_test_insn != get_last_insn ()) |
| { |
| /* We found one. Move everything from there up |
| to the end of the loop, and add a jump into the loop |
| to jump to there. */ |
| register rtx newstart_label = gen_label_rtx (); |
| register rtx start_move = start_label; |
| |
| /* If the start label is preceded by a NOTE_INSN_LOOP_CONT note, |
| then we want to move this note also. */ |
| if (GET_CODE (PREV_INSN (start_move)) == NOTE |
| && (NOTE_LINE_NUMBER (PREV_INSN (start_move)) |
| == NOTE_INSN_LOOP_CONT)) |
| start_move = PREV_INSN (start_move); |
| |
| emit_label_after (newstart_label, PREV_INSN (start_move)); |
| reorder_insns (start_move, last_test_insn, get_last_insn ()); |
| emit_jump_insn_after (gen_jump (start_label), |
| PREV_INSN (newstart_label)); |
| emit_barrier_after (PREV_INSN (newstart_label)); |
| start_label = newstart_label; |
| } |
| } |
| |
| emit_jump (start_label); |
| emit_note (NULL_PTR, NOTE_INSN_LOOP_END); |
| emit_label (loop_stack->data.loop.end_label); |
| |
| POPSTACK (loop_stack); |
| |
| last_expr_type = 0; |
| } |
| |
| /* Generate a jump to the current loop's continue-point. |
| This is usually the top of the loop, but may be specified |
| explicitly elsewhere. If not currently inside a loop, |
| return 0 and do nothing; caller will print an error message. */ |
| |
| int |
| expand_continue_loop (whichloop) |
| struct nesting *whichloop; |
| { |
| last_expr_type = 0; |
| if (whichloop == 0) |
| whichloop = loop_stack; |
| if (whichloop == 0) |
| return 0; |
| expand_goto_internal (NULL_TREE, whichloop->data.loop.continue_label, |
| NULL_RTX); |
| return 1; |
| } |
| |
| /* Generate a jump to exit the current loop. If not currently inside a loop, |
| return 0 and do nothing; caller will print an error message. */ |
| |
| int |
| expand_exit_loop (whichloop) |
| struct nesting *whichloop; |
| { |
| last_expr_type = 0; |
| if (whichloop == 0) |
| whichloop = loop_stack; |
| if (whichloop == 0) |
| return 0; |
| expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, NULL_RTX); |
| return 1; |
| } |
| |
| /* Generate a conditional jump to exit the current loop if COND |
| evaluates to zero. If not currently inside a loop, |
| return 0 and do nothing; caller will print an error message. */ |
| |
| int |
| expand_exit_loop_if_false (whichloop, cond) |
| struct nesting *whichloop; |
| tree cond; |
| { |
| last_expr_type = 0; |
| if (whichloop == 0) |
| whichloop = loop_stack; |
| if (whichloop == 0) |
| return 0; |
| if (output_bytecode) |
| { |
| bc_expand_expr (cond); |
| bc_expand_goto_internal (xjumpifnot, |
| BYTECODE_BC_LABEL (whichloop->exit_label), |
| NULL_TREE); |
| } |
| else |
| { |
| /* In order to handle fixups, we actually create a conditional jump |
| around a unconditional branch to exit the loop. If fixups are |
| necessary, they go before the unconditional branch. */ |
| |
| rtx label = gen_label_rtx (); |
| rtx last_insn; |
| |
| do_jump (cond, NULL_RTX, label); |
| last_insn = get_last_insn (); |
| if (GET_CODE (last_insn) == CODE_LABEL) |
| whichloop->data.loop.alt_end_label = last_insn; |
| expand_goto_internal (NULL_TREE, whichloop->data.loop.end_label, |
| NULL_RTX); |
| emit_label (label); |
| } |
| |
| return 1; |
| } |
| |
| /* Return non-zero if we should preserve sub-expressions as separate |
| pseudos. We never do so if we aren't optimizing. We always do so |
| if -fexpensive-optimizations. |
| |
| Otherwise, we only do so if we are in the "early" part of a loop. I.e., |
| the loop may still be a small one. */ |
| |
| int |
| preserve_subexpressions_p () |
| { |
| rtx insn; |
| |
| if (flag_expensive_optimizations) |
| return 1; |
| |
| if (optimize == 0 || loop_stack == 0) |
| return 0; |
| |
| insn = get_last_insn_anywhere (); |
| |
| return (insn |
| && (INSN_UID (insn) - INSN_UID (loop_stack->data.loop.start_label) |
| < n_non_fixed_regs * 3)); |
| |
| } |
| |
| /* Generate a jump to exit the current loop, conditional, binding contour |
| or case statement. Not all such constructs are visible to this function, |
| only those started with EXIT_FLAG nonzero. Individual languages use |
| the EXIT_FLAG parameter to control which kinds of constructs you can |
| exit this way. |
| |
| If not currently inside anything that can be exited, |
| return 0 and do nothing; caller will print an error message. */ |
| |
| int |
| expand_exit_something () |
| { |
| struct nesting *n; |
| last_expr_type = 0; |
| for (n = nesting_stack; n; n = n->all) |
| if (n->exit_label != 0) |
| { |
| expand_goto_internal (NULL_TREE, n->exit_label, NULL_RTX); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /* Generate RTL to return from the current function, with no value. |
| (That is, we do not do anything about returning any value.) */ |
| |
| void |
| expand_null_return () |
| { |
| struct nesting *block = block_stack; |
| rtx last_insn = 0; |
| |
| if (output_bytecode) |
| { |
| bc_emit_instruction (ret); |
| return; |
| } |
| |
| /* Does any pending block have cleanups? */ |
| |
| while (block && block->data.block.cleanups == 0) |
| block = block->next; |
| |
| /* If yes, use a goto to return, since that runs cleanups. */ |
| |
| expand_null_return_1 (last_insn, block != 0); |
| } |
| |
| /* Generate RTL to return from the current function, with value VAL. */ |
| |
| static void |
| expand_value_return (val) |
| rtx val; |
| { |
| struct nesting *block = block_stack; |
| rtx last_insn = get_last_insn (); |
| rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); |
| |
| /* Copy the value to the return location |
| unless it's already there. */ |
| |
| if (return_reg != val) |
| { |
| #ifdef PROMOTE_FUNCTION_RETURN |
| tree type = TREE_TYPE (DECL_RESULT (current_function_decl)); |
| int unsignedp = TREE_UNSIGNED (type); |
| enum machine_mode mode |
| = promote_mode (type, DECL_MODE (DECL_RESULT (current_function_decl)), |
| &unsignedp, 1); |
| |
| if (GET_MODE (val) != VOIDmode && GET_MODE (val) != mode) |
| convert_move (return_reg, val, unsignedp); |
| else |
| #endif |
| emit_move_insn (return_reg, val); |
| } |
| if (GET_CODE (return_reg) == REG |
| && REGNO (return_reg) < FIRST_PSEUDO_REGISTER) |
| emit_insn (gen_rtx (USE, VOIDmode, return_reg)); |
| /* Handle calls that return values in multiple non-contiguous locations. |
| The Irix 6 ABI has examples of this. */ |
| else if (GET_CODE (return_reg) == PARALLEL) |
| { |
| int i; |
| |
| for (i = 0; i < XVECLEN (return_reg, 0); i++) |
| { |
| rtx x = XEXP (XVECEXP (return_reg, 0, i), 0); |
| |
| if (GET_CODE (x) == REG |
| && REGNO (x) < FIRST_PSEUDO_REGISTER) |
| emit_insn (gen_rtx (USE, VOIDmode, x)); |
| } |
| } |
| |
| /* Does any pending block have cleanups? */ |
| |
| while (block && block->data.block.cleanups == 0) |
| block = block->next; |
| |
| /* If yes, use a goto to return, since that runs cleanups. |
| Use LAST_INSN to put cleanups *before* the move insn emitted above. */ |
| |
| expand_null_return_1 (last_insn, block != 0); |
| } |
| |
| /* Output a return with no value. If LAST_INSN is nonzero, |
| pretend that the return takes place after LAST_INSN. |
| If USE_GOTO is nonzero then don't use a return instruction; |
| go to the return label instead. This causes any cleanups |
| of pending blocks to be executed normally. */ |
| |
| static void |
| expand_null_return_1 (last_insn, use_goto) |
| rtx last_insn; |
| int use_goto; |
| { |
| rtx end_label = cleanup_label ? cleanup_label : return_label; |
| |
| clear_pending_stack_adjust (); |
| do_pending_stack_adjust (); |
| last_expr_type = 0; |
| |
| /* PCC-struct return always uses an epilogue. */ |
| if (current_function_returns_pcc_struct || use_goto) |
| { |
| if (end_label == 0) |
| end_label = return_label = gen_label_rtx (); |
| expand_goto_internal (NULL_TREE, end_label, last_insn); |
| return; |
| } |
| |
| /* Otherwise output a simple return-insn if one is available, |
| unless it won't do the job. */ |
| #ifdef HAVE_return |
| if (HAVE_return && use_goto == 0 && cleanup_label == 0) |
| { |
| emit_jump_insn (gen_return ()); |
| emit_barrier (); |
| return; |
| } |
| #endif |
| |
| /* Otherwise jump to the epilogue. */ |
| expand_goto_internal (NULL_TREE, end_label, last_insn); |
| } |
| |
| /* Generate RTL to evaluate the expression RETVAL and return it |
| from the current function. */ |
| |
| void |
| expand_return (retval) |
| tree retval; |
| { |
| /* If there are any cleanups to be performed, then they will |
| be inserted following LAST_INSN. It is desirable |
| that the last_insn, for such purposes, should be the |
| last insn before computing the return value. Otherwise, cleanups |
| which call functions can clobber the return value. */ |
| /* ??? rms: I think that is erroneous, because in C++ it would |
| run destructors on variables that might be used in the subsequent |
| computation of the return value. */ |
| rtx last_insn = 0; |
| register rtx val = 0; |
| register rtx op0; |
| tree retval_rhs; |
| int cleanups; |
| struct nesting *block; |
| |
| /* Bytecode returns are quite simple, just leave the result on the |
| arithmetic stack. */ |
| if (output_bytecode) |
| { |
| bc_expand_expr (retval); |
| bc_emit_instruction (ret); |
| return; |
| } |
| |
| /* If function wants no value, give it none. */ |
| if (TREE_CODE (TREE_TYPE (TREE_TYPE (current_function_decl))) == VOID_TYPE) |
| { |
| expand_expr (retval, NULL_RTX, VOIDmode, 0); |
| emit_queue (); |
| expand_null_return (); |
| return; |
| } |
| |
| /* Are any cleanups needed? E.g. C++ destructors to be run? */ |
| /* This is not sufficient. We also need to watch for cleanups of the |
| expression we are about to expand. Unfortunately, we cannot know |
| if it has cleanups until we expand it, and we want to change how we |
| expand it depending upon if we need cleanups. We can't win. */ |
| #if 0 |
| cleanups = any_pending_cleanups (1); |
| #else |
| cleanups = 1; |
| #endif |
| |
| if (TREE_CODE (retval) == RESULT_DECL) |
| retval_rhs = retval; |
| else if ((TREE_CODE (retval) == MODIFY_EXPR || TREE_CODE (retval) == INIT_EXPR) |
| && TREE_CODE (TREE_OPERAND (retval, 0)) == RESULT_DECL) |
| retval_rhs = TREE_OPERAND (retval, 1); |
| else if (TREE_TYPE (retval) == void_type_node) |
| /* Recognize tail-recursive call to void function. */ |
| retval_rhs = retval; |
| else |
| retval_rhs = NULL_TREE; |
| |
| /* Only use `last_insn' if there are cleanups which must be run. */ |
| if (cleanups || cleanup_label != 0) |
| last_insn = get_last_insn (); |
| |
| /* Distribute return down conditional expr if either of the sides |
| may involve tail recursion (see test below). This enhances the number |
| of tail recursions we see. Don't do this always since it can produce |
| sub-optimal code in some cases and we distribute assignments into |
| conditional expressions when it would help. */ |
| |
| if (optimize && retval_rhs != 0 |
| && frame_offset == 0 |
| && TREE_CODE (retval_rhs) == COND_EXPR |
| && (TREE_CODE (TREE_OPERAND (retval_rhs, 1)) == CALL_EXPR |
| || TREE_CODE (TREE_OPERAND (retval_rhs, 2)) == CALL_EXPR)) |
| { |
| rtx label = gen_label_rtx (); |
| tree expr; |
| |
| do_jump (TREE_OPERAND (retval_rhs, 0), label, NULL_RTX); |
| expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)), |
| DECL_RESULT (current_function_decl), |
| TREE_OPERAND (retval_rhs, 1)); |
| TREE_SIDE_EFFECTS (expr) = 1; |
| expand_return (expr); |
| emit_label (label); |
| |
| expr = build (MODIFY_EXPR, TREE_TYPE (TREE_TYPE (current_function_decl)), |
| DECL_RESULT (current_function_decl), |
| TREE_OPERAND (retval_rhs, 2)); |
| TREE_SIDE_EFFECTS (expr) = 1; |
| expand_return (expr); |
| return; |
| } |
| |
| /* For tail-recursive call to current function, |
| just jump back to the beginning. |
| It's unsafe if any auto variable in this function |
| has its address taken; for simplicity, |
| require stack frame to be empty. */ |
| if (optimize && retval_rhs != 0 |
| && frame_offset == 0 |
| && TREE_CODE (retval_rhs) == CALL_EXPR |
| && TREE_CODE (TREE_OPERAND (retval_rhs, 0)) == ADDR_EXPR |
| && TREE_OPERAND (TREE_OPERAND (retval_rhs, 0), 0) == current_function_decl |
| /* Finish checking validity, and if valid emit code |
| to set the argument variables for the new call. */ |
| && tail_recursion_args (TREE_OPERAND (retval_rhs, 1), |
| DECL_ARGUMENTS (current_function_decl))) |
| { |
| if (tail_recursion_label == 0) |
| { |
| tail_recursion_label = gen_label_rtx (); |
| emit_label_after (tail_recursion_label, |
| tail_recursion_reentry); |
| } |
| emit_queue (); |
| expand_goto_internal (NULL_TREE, tail_recursion_label, last_insn); |
| emit_barrier (); |
| return; |
| } |
| #ifdef HAVE_return |
| /* This optimization is safe if there are local cleanups |
| because expand_null_return takes care of them. |
| ??? I think it should also be safe when there is a cleanup label, |
| because expand_null_return takes care of them, too. |
| Any reason why not? */ |
| if (HAVE_return && cleanup_label == 0 |
| && ! current_function_returns_pcc_struct |
| && BRANCH_COST <= 1) |
| { |
| /* If this is return x == y; then generate |
| if (x == y) return 1; else return 0; |
| if we can do it with explicit return insns and branches are cheap, |
| but not if we have the corresponding scc insn. */ |
| int has_scc = 0; |
| if (retval_rhs) |
| switch (TREE_CODE (retval_rhs)) |
| { |
| case EQ_EXPR: |
| #ifdef HAVE_seq |
| has_scc = HAVE_seq; |
| #endif |
| case NE_EXPR: |
| #ifdef HAVE_sne |
| has_scc = HAVE_sne; |
| #endif |
| case GT_EXPR: |
| #ifdef HAVE_sgt |
| has_scc = HAVE_sgt; |
| #endif |
| case GE_EXPR: |
| #ifdef HAVE_sge |
| has_scc = HAVE_sge; |
| #endif |
| case LT_EXPR: |
| #ifdef HAVE_slt |
| has_scc = HAVE_slt; |
| #endif |
| case LE_EXPR: |
| #ifdef HAVE_sle |
| has_scc = HAVE_sle; |
| #endif |
| case TRUTH_ANDIF_EXPR: |
| case TRUTH_ORIF_EXPR: |
| case TRUTH_AND_EXPR: |
| case TRUTH_OR_EXPR: |
| case TRUTH_NOT_EXPR: |
| case TRUTH_XOR_EXPR: |
| if (! has_scc) |
| { |
| op0 = gen_label_rtx (); |
| jumpifnot (retval_rhs, op0); |
| expand_value_return (const1_rtx); |
| emit_label (op0); |
| expand_value_return (const0_rtx); |
| return; |
| } |
| } |
| } |
| #endif /* HAVE_return */ |
| |
| /* If the result is an aggregate that is being returned in one (or more) |
| registers, load the registers here. The compiler currently can't handle |
| copying a BLKmode value into registers. We could put this code in a |
| more general area (for use by everyone instead of just function |
| call/return), but until this feature is generally usable it is kept here |
| (and in expand_call). The value must go into a pseudo in case there |
| are cleanups that will clobber the real return register. */ |
| |
| if (retval_rhs != 0 |
| && TYPE_MODE (TREE_TYPE (retval_rhs)) == BLKmode |
| && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) |
| { |
| int i, bitpos, xbitpos; |
| int big_endian_correction = 0; |
| int bytes = int_size_in_bytes (TREE_TYPE (retval_rhs)); |
| int n_regs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD; |
| int bitsize = MIN (TYPE_ALIGN (TREE_TYPE (retval_rhs)),BITS_PER_WORD); |
| rtx *result_pseudos = (rtx *) alloca (sizeof (rtx) * n_regs); |
| rtx result_reg, src, dst; |
| rtx result_val = expand_expr (retval_rhs, NULL_RTX, VOIDmode, 0); |
| enum machine_mode tmpmode, result_reg_mode; |
| |
| /* Structures whose size is not a multiple of a word are aligned |
| to the least significant byte (to the right). On a BYTES_BIG_ENDIAN |
| machine, this means we must skip the empty high order bytes when |
| calculating the bit offset. */ |
| if (BYTES_BIG_ENDIAN && bytes % UNITS_PER_WORD) |
| big_endian_correction = (BITS_PER_WORD - ((bytes % UNITS_PER_WORD) |
| * BITS_PER_UNIT)); |
| |
| /* Copy the structure BITSIZE bits at a time. */ |
| for (bitpos = 0, xbitpos = big_endian_correction; |
| bitpos < bytes * BITS_PER_UNIT; |
| bitpos += bitsize, xbitpos += bitsize) |
| { |
| /* We need a new destination pseudo each time xbitpos is |
| on a word boundary and when xbitpos == big_endian_correction |
| (the first time through). */ |
| if (xbitpos % BITS_PER_WORD == 0 |
| || xbitpos == big_endian_correction) |
| { |
| /* Generate an appropriate register. */ |
| dst = gen_reg_rtx (word_mode); |
| result_pseudos[xbitpos / BITS_PER_WORD] = dst; |
| |
| /* Clobber the destination before we move anything into it. */ |
| emit_insn (gen_rtx (CLOBBER, VOIDmode, dst)); |
| } |
| |
| /* We need a new source operand each time bitpos is on a word |
| boundary. */ |
| if (bitpos % BITS_PER_WORD == 0) |
| src = operand_subword_force (result_val, |
| bitpos / BITS_PER_WORD, |
| BLKmode); |
| |
| /* Use bitpos for the source extraction (left justified) and |
| xbitpos for the destination store (right justified). */ |
| store_bit_field (dst, bitsize, xbitpos % BITS_PER_WORD, word_mode, |
| extract_bit_field (src, bitsize, |
| bitpos % BITS_PER_WORD, 1, |
| NULL_RTX, word_mode, |
| word_mode, |
| bitsize / BITS_PER_UNIT, |
| BITS_PER_WORD), |
| bitsize / BITS_PER_UNIT, BITS_PER_WORD); |
| } |
| |
| /* Find the smallest integer mode large enough to hold the |
| entire structure and use that mode instead of BLKmode |
| on the USE insn for the return register. */ |
| bytes = int_size_in_bytes (TREE_TYPE (retval_rhs)); |
| for (tmpmode = GET_CLASS_NARROWEST_MODE (MODE_INT); |
| tmpmode != MAX_MACHINE_MODE; |
| tmpmode = GET_MODE_WIDER_MODE (tmpmode)) |
| { |
| /* Have we found a large enough mode? */ |
| if (GET_MODE_SIZE (tmpmode) >= bytes) |
| break; |
| } |
| |
| /* No suitable mode found. */ |
| if (tmpmode == MAX_MACHINE_MODE) |
| abort (); |
| |
| PUT_MODE (DECL_RTL (DECL_RESULT (current_function_decl)), tmpmode); |
| |
| if (GET_MODE_SIZE (tmpmode) < GET_MODE_SIZE (word_mode)) |
| result_reg_mode = word_mode; |
| else |
| result_reg_mode = tmpmode; |
| result_reg = gen_reg_rtx (result_reg_mode); |
| |
| emit_queue (); |
| for (i = 0; i < n_regs; i++) |
| emit_move_insn (operand_subword (result_reg, i, 0, result_reg_mode), |
| result_pseudos[i]); |
| |
| if (tmpmode != result_reg_mode) |
| result_reg = gen_lowpart (tmpmode, result_reg); |
| |
| expand_value_return (result_reg); |
| } |
| else if (cleanups |
| && retval_rhs != 0 |
| && TREE_TYPE (retval_rhs) != void_type_node |
| && GET_CODE (DECL_RTL (DECL_RESULT (current_function_decl))) == REG) |
| { |
| /* Calculate the return value into a pseudo reg. */ |
| val = gen_reg_rtx (DECL_MODE (DECL_RESULT (current_function_decl))); |
| val = expand_expr (retval_rhs, val, GET_MODE (val), 0); |
| val = force_not_mem (val); |
| emit_queue (); |
| /* Return the calculated value, doing cleanups first. */ |
| expand_value_return (val); |
| } |
| else |
| { |
| /* No cleanups or no hard reg used; |
| calculate value into hard return reg. */ |
| expand_expr (retval, const0_rtx, VOIDmode, 0); |
| emit_queue (); |
| expand_value_return (DECL_RTL (DECL_RESULT (current_function_decl))); |
| } |
| } |
| |
| /* Return 1 if the end of the generated RTX is not a barrier. |
| This means code already compiled can drop through. */ |
| |
| int |
| drop_through_at_end_p () |
| { |
| rtx insn = get_last_insn (); |
| while (insn && GET_CODE (insn) == NOTE) |
| insn = PREV_INSN (insn); |
| return insn && GET_CODE (insn) != BARRIER; |
| } |
| |
| /* Emit code to alter this function's formal parms for a tail-recursive call. |
| ACTUALS is a list of actual parameter expressions (chain of TREE_LISTs). |
| FORMALS is the chain of decls of formals. |
| Return 1 if this can be done; |
| otherwise return 0 and do not emit any code. */ |
| |
| static int |
| tail_recursion_args (actuals, formals) |
| tree actuals, formals; |
| { |
| register tree a = actuals, f = formals; |
| register int i; |
| register rtx *argvec; |
| |
| /* Check that number and types of actuals are compatible |
| with the formals. This is not always true in valid C code. |
| Also check that no formal needs to be addressable |
| and that all formals are scalars. */ |
| |
| /* Also count the args. */ |
| |
| for (a = actuals, f = formals, i = 0; a && f; a = TREE_CHAIN (a), f = TREE_CHAIN (f), i++) |
| { |
| if (TYPE_MAIN_VARIANT (TREE_TYPE (TREE_VALUE (a))) |
| != TYPE_MAIN_VARIANT (TREE_TYPE (f))) |
| return 0; |
| if (GET_CODE (DECL_RTL (f)) != REG || DECL_MODE (f) == BLKmode) |
| return 0; |
| } |
| if (a != 0 || f != 0) |
| return 0; |
| |
| /* Compute all the actuals. */ |
| |
| argvec = (rtx *) alloca (i * sizeof (rtx)); |
| |
| for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) |
| argvec[i] = expand_expr (TREE_VALUE (a), NULL_RTX, VOIDmode, 0); |
| |
| /* Find which actual values refer to current values of previous formals. |
| Copy each of them now, before any formal is changed. */ |
| |
| for (a = actuals, i = 0; a; a = TREE_CHAIN (a), i++) |
| { |
| int copy = 0; |
| register int j; |
| for (f = formals, j = 0; j < i; f = TREE_CHAIN (f), j++) |
| if (reg_mentioned_p (DECL_RTL (f), argvec[i])) |
| { copy = 1; break; } |
| if (copy) |
| argvec[i] = copy_to_reg (argvec[i]); |
| } |
| |
| /* Store the values of the actuals into the formals. */ |
| |
| for (f = formals, a = actuals, i = 0; f; |
| f = TREE_CHAIN (f), a = TREE_CHAIN (a), i++) |
| { |
| if (GET_MODE (DECL_RTL (f)) == GET_MODE (argvec[i])) |
| emit_move_insn (DECL_RTL (f), argvec[i]); |
| else |
| convert_move (DECL_RTL (f), argvec[i], |
| TREE_UNSIGNED (TREE_TYPE (TREE_VALUE (a)))); |
| } |
| |
| free_temp_slots (); |
| return 1; |
| } |
| |
| /* Generate the RTL code for entering a binding contour. |
| The variables are declared one by one, by calls to `expand_decl'. |
| |
| EXIT_FLAG is nonzero if this construct should be visible to |
| `exit_something'. */ |
| |
| void |
| expand_start_bindings (exit_flag) |
| int exit_flag; |
| { |
| struct nesting *thisblock = ALLOC_NESTING (); |
| rtx note = output_bytecode ? 0 : emit_note (NULL_PTR, NOTE_INSN_BLOCK_BEG); |
| |
| /* Make an entry on block_stack for the block we are entering. */ |
| |
| thisblock->next = block_stack; |
| thisblock->all = nesting_stack; |
| thisblock->depth = ++nesting_depth; |
| thisblock->data.block.stack_level = 0; |
| thisblock->data.block.cleanups = 0; |
| thisblock->data.block.function_call_count = 0; |
| thisblock->data.block.exception_region = 0; |
| thisblock->data.block.target_temp_slot_level = target_temp_slot_level; |
| |
| thisblock->data.block.conditional_code = 0; |
| thisblock->data.block.last_unconditional_cleanup = note; |
| thisblock->data.block.cleanup_ptr = &thisblock->data.block.cleanups; |
| |
| if (block_stack |
| && !(block_stack->data.block.cleanups == NULL_TREE |
| && block_stack->data.block.outer_cleanups == NULL_TREE)) |
| thisblock->data.block.outer_cleanups |
| = tree_cons (NULL_TREE, block_stack->data.block.cleanups, |
| block_stack->data.block.outer_cleanups); |
| else |
| thisblock->data.block.outer_cleanups = 0; |
| thisblock->data.block.label_chain = 0; |
| thisblock->data.block.innermost_stack_block = stack_block_stack; |
| thisblock->data.block.first_insn = note; |
| thisblock->data.block.block_start_count = ++block_start_count; |
| thisblock->exit_label = exit_flag ? gen_label_rtx () : 0; |
| block_stack = thisblock; |
| nesting_stack = thisblock; |
| |
| if (!output_bytecode) |
| { |
| /* Make a new level for allocating stack slots. */ |
| push_temp_slots (); |
| } |
| } |
| |
| /* Specify the scope of temporaries created by TARGET_EXPRs. Similar |
| to CLEANUP_POINT_EXPR, but handles cases when a series of calls to |
| expand_expr are made. After we end the region, we know that all |
| space for all temporaries that were created by TARGET_EXPRs will be |
| destroyed and their space freed for reuse. */ |
| |
| void |
| expand_start_target_temps () |
| { |
| /* This is so that even if the result is preserved, the space |
| allocated will be freed, as we know that it is no longer in use. */ |
| push_temp_slots (); |
| |
| /* Start a new binding layer that will keep track of all cleanup |
| actions to be performed. */ |
| expand_start_bindings (0); |
| |
| target_temp_slot_level = temp_slot_level; |
| } |
| |
| void |
| expand_end_target_temps () |
| { |
| expand_end_bindings (NULL_TREE, 0, 0); |
| |
| /* This is so that even if the result is preserved, the space |
| allocated will be freed, as we know that it is no longer in use. */ |
| pop_temp_slots (); |
| } |
| |
| /* Mark top block of block_stack as an implicit binding for an |
| exception region. This is used to prevent infinite recursion when |
| ending a binding with expand_end_bindings. It is only ever called |
| by expand_eh_region_start, as that it the only way to create a |
| block stack for a exception region. */ |
| |
| void |
| mark_block_as_eh_region () |
| { |
| block_stack->data.block.exception_region = 1; |
| if (block_stack->next |
| && block_stack->next->data.block.conditional_code) |
| { |
| block_stack->data.block.conditional_code |
| = block_stack->next->data.block.conditional_code; |
| block_stack->data.block.last_unconditional_cleanup |
| = block_stack->next->data.block.last_unconditional_cleanup; |
| block_stack->data.block.cleanup_ptr |
| = block_stack->next->data.block.cleanup_ptr; |
| } |
| } |
| |
| /* True if we are currently emitting insns in an area of output code |
| that is controlled by a conditional expression. This is used by |
| the cleanup handling code to generate conditional cleanup actions. */ |
| |
| int |
| conditional_context () |
| { |
| return block_stack && block_stack->data.block.conditional_code; |
| } |
| |
| /* Mark top block of block_stack as not for an implicit binding for an |
| exception region. This is only ever done by expand_eh_region_end |
| to let expand_end_bindings know that it is being called explicitly |
| to end the binding layer for just the binding layer associated with |
| the exception region, otherwise expand_end_bindings would try and |
| end all implicit binding layers for exceptions regions, and then |
| one normal binding layer. */ |
| |
| void |
| mark_block_as_not_eh_region () |
| { |
| block_stack->data.block.exception_region = 0; |
| } |
| |
| /* True if the top block of block_stack was marked as for an exception |
| region by mark_block_as_eh_region. */ |
| |
| int |
| is_eh_region () |
| { |
| return block_stack && block_stack->data.block.exception_region; |
| } |
| |
| /* Given a pointer to a BLOCK node, save a pointer to the most recently |
| generated NOTE_INSN_BLOCK_END in the BLOCK_END_NOTE field of the given |
| BLOCK node. */ |
| |
| void |
| remember_end_note (block) |
| register tree block; |
| { |
| BLOCK_END_NOTE (block) = last_block_end_note; |
| last_block_end_note = NULL_RTX; |
| } |
| |
| /* Generate RTL code to terminate a binding contour. |
| VARS is the chain of VAR_DECL nodes |
| for the variables bound in this contour. |
| MARK_ENDS is nonzero if we should put a note at the beginning |
| and end of this binding contour. |
| |
| DONT_JUMP_IN is nonzero if it is not valid to jump into this contour. |
| (That is true automatically if the contour has a saved stack level.) */ |
| |
| void |
| expand_end_bindings (vars, mark_ends, dont_jump_in) |
| tree vars; |
| int mark_ends; |
| int dont_jump_in; |
| { |
| register struct nesting *thisblock; |
| register tree decl; |
| |
| while (block_stack->data.block.exception_region) |
| { |
| /* Because we don't need or want a new temporary level and |
| because we didn't create one in expand_eh_region_start, |
| create a fake one now to avoid removing one in |
| expand_end_bindings. */ |
| push_temp_slots (); |
| |
| block_stack->data.block.exception_region = 0; |
| |
| expand_end_bindings (NULL_TREE, 0, 0); |
| } |
| |
| if (output_bytecode) |
| { |
| bc_expand_end_bindings (vars, mark_ends, dont_jump_in); |
| return; |
| } |
| |
| /* Since expand_eh_region_start does an expand_start_bindings, we |
| have to first end all the bindings that were created by |
| expand_eh_region_start. */ |
| |
| thisblock = block_stack; |
| |
| if (warn_unused |