| /* SSA operands management for trees. |
| Copyright (C) 2003-2022 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC 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 3, or (at your option) |
| any later version. |
| |
| GCC 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 GCC; see the file COPYING3. If not see |
| <http://www.gnu.org/licenses/>. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "coretypes.h" |
| #include "backend.h" |
| #include "tree.h" |
| #include "gimple.h" |
| #include "timevar.h" |
| #include "ssa.h" |
| #include "gimple-pretty-print.h" |
| #include "diagnostic-core.h" |
| #include "stmt.h" |
| #include "print-tree.h" |
| #include "dumpfile.h" |
| #include "value-query.h" |
| |
| |
| /* This file contains the code required to manage the operands cache of the |
| SSA optimizer. For every stmt, we maintain an operand cache in the stmt |
| annotation. This cache contains operands that will be of interest to |
| optimizers and other passes wishing to manipulate the IL. |
| |
| The operand type are broken up into REAL and VIRTUAL operands. The real |
| operands are represented as pointers into the stmt's operand tree. Thus |
| any manipulation of the real operands will be reflected in the actual tree. |
| Virtual operands are represented solely in the cache, although the base |
| variable for the SSA_NAME may, or may not occur in the stmt's tree. |
| Manipulation of the virtual operands will not be reflected in the stmt tree. |
| |
| The routines in this file are concerned with creating this operand cache |
| from a stmt tree. |
| |
| The operand tree is the parsed by the various get_* routines which look |
| through the stmt tree for the occurrence of operands which may be of |
| interest, and calls are made to the append_* routines whenever one is |
| found. There are 4 of these routines, each representing one of the |
| 4 types of operands. Defs, Uses, Virtual Uses, and Virtual May Defs. |
| |
| The append_* routines check for duplication, and simply keep a list of |
| unique objects for each operand type in the build_* extendable vectors. |
| |
| Once the stmt tree is completely parsed, the finalize_ssa_operands() |
| routine is called, which proceeds to perform the finalization routine |
| on each of the 4 operand vectors which have been built up. |
| |
| If the stmt had a previous operand cache, the finalization routines |
| attempt to match up the new operands with the old ones. If it's a perfect |
| match, the old vector is simply reused. If it isn't a perfect match, then |
| a new vector is created and the new operands are placed there. For |
| virtual operands, if the previous cache had SSA_NAME version of a |
| variable, and that same variable occurs in the same operands cache, then |
| the new cache vector will also get the same SSA_NAME. |
| |
| i.e., if a stmt had a VUSE of 'a_5', and 'a' occurs in the new |
| operand vector for VUSE, then the new vector will also be modified |
| such that it contains 'a_5' rather than 'a'. */ |
| |
| |
| /* Flags to describe operand properties in helpers. */ |
| |
| /* By default, operands are loaded. */ |
| #define opf_use 0 |
| |
| /* Operand is the target of an assignment expression or a |
| call-clobbered variable. */ |
| #define opf_def (1 << 0) |
| |
| /* No virtual operands should be created in the expression. This is used |
| when traversing ADDR_EXPR nodes which have different semantics than |
| other expressions. Inside an ADDR_EXPR node, the only operands that we |
| need to consider are indices into arrays. For instance, &a.b[i] should |
| generate a USE of 'i' but it should not generate a VUSE for 'a' nor a |
| VUSE for 'b'. */ |
| #define opf_no_vops (1 << 1) |
| |
| /* Operand is in a place where address-taken does not imply addressable. */ |
| #define opf_non_addressable (1 << 3) |
| |
| /* Operand is in a place where opf_non_addressable does not apply. */ |
| #define opf_not_non_addressable (1 << 4) |
| |
| /* Operand is having its address taken. */ |
| #define opf_address_taken (1 << 5) |
| |
| /* Class containing temporary per-stmt state. */ |
| |
| class operands_scanner |
| { |
| public: |
| operands_scanner (struct function *fun, gimple *statement) |
| { |
| build_vuse = NULL_TREE; |
| build_vdef = NULL_TREE; |
| fn = fun; |
| stmt = statement; |
| } |
| |
| /* Create an operands cache for STMT. */ |
| void build_ssa_operands (); |
| |
| /* Verifies SSA statement operands. */ |
| DEBUG_FUNCTION bool verify_ssa_operands (); |
| |
| private: |
| /* Disable copy and assign of this class, as it may have problems with |
| build_uses vec. */ |
| DISABLE_COPY_AND_ASSIGN (operands_scanner); |
| |
| /* Array for building all the use operands. */ |
| auto_vec<tree *, 16> build_uses; |
| |
| /* The built VDEF operand. */ |
| tree build_vdef; |
| |
| /* The built VUSE operand. */ |
| tree build_vuse; |
| |
| /* Function which STMT belongs to. */ |
| struct function *fn; |
| |
| /* Statement to work on. */ |
| gimple *stmt; |
| |
| /* Takes elements from build_uses and turns them into use operands of STMT. */ |
| void finalize_ssa_uses (); |
| |
| /* Clear the in_list bits and empty the build array for VDEFs and |
| VUSEs. */ |
| void cleanup_build_arrays (); |
| |
| /* Finalize all the build vectors, fill the new ones into INFO. */ |
| void finalize_ssa_stmt_operands (); |
| |
| /* Start the process of building up operands vectors in INFO. */ |
| void start_ssa_stmt_operands (); |
| |
| /* Add USE_P to the list of pointers to operands. */ |
| void append_use (tree *use_p); |
| |
| /* Add VAR to the set of variables that require a VDEF operator. */ |
| void append_vdef (tree var); |
| |
| /* Add VAR to the set of variables that require a VUSE operator. */ |
| void append_vuse (tree var); |
| |
| /* Add virtual operands for STMT. FLAGS is as in get_expr_operands. */ |
| void add_virtual_operand (int flags); |
| |
| |
| /* Add *VAR_P to the appropriate operand array for statement STMT. |
| FLAGS is as in get_expr_operands. If *VAR_P is a GIMPLE register, |
| it will be added to the statement's real operands, otherwise it is |
| added to virtual operands. */ |
| void add_stmt_operand (tree *var_p, int flags); |
| |
| /* A subroutine of get_expr_operands to handle MEM_REF. |
| |
| STMT is the statement being processed, EXPR is the MEM_REF |
| that got us here. |
| |
| FLAGS is as in get_expr_operands. */ |
| void get_mem_ref_operands (tree expr, int flags); |
| |
| /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ |
| void get_tmr_operands (tree expr, int flags); |
| |
| |
| /* If STMT is a call that may clobber globals and other symbols that |
| escape, add them to the VDEF/VUSE lists for it. */ |
| void maybe_add_call_vops (gcall *stmt); |
| |
| /* Scan operands in the ASM_EXPR stmt referred to in INFO. */ |
| void get_asm_stmt_operands (gasm *stmt); |
| |
| |
| /* Recursively scan the expression pointed to by EXPR_P in statement |
| STMT. FLAGS is one of the OPF_* constants modifying how to |
| interpret the operands found. */ |
| void get_expr_operands (tree *expr_p, int flags); |
| |
| /* Parse STMT looking for operands. When finished, the various |
| build_* operand vectors will have potential operands in them. */ |
| void parse_ssa_operands (); |
| |
| |
| /* Takes elements from build_defs and turns them into def operands of STMT. |
| TODO -- Make build_defs vec of tree *. */ |
| void finalize_ssa_defs (); |
| }; |
| |
| /* Accessor to tree-ssa-operands.cc caches. */ |
| static inline struct ssa_operands * |
| gimple_ssa_operands (const struct function *fun) |
| { |
| return &fun->gimple_df->ssa_operands; |
| } |
| |
| |
| /* Return true if the SSA operands cache is active. */ |
| |
| bool |
| ssa_operands_active (struct function *fun) |
| { |
| if (fun == NULL) |
| return false; |
| |
| return fun->gimple_df && gimple_ssa_operands (fun)->ops_active; |
| } |
| |
| |
| /* Create the VOP variable, an artificial global variable to act as a |
| representative of all of the virtual operands FUD chain. */ |
| |
| static void |
| create_vop_var (struct function *fn) |
| { |
| tree global_var; |
| |
| gcc_assert (fn->gimple_df->vop == NULL_TREE); |
| |
| global_var = build_decl (BUILTINS_LOCATION, VAR_DECL, |
| get_identifier (".MEM"), |
| void_type_node); |
| DECL_ARTIFICIAL (global_var) = 1; |
| DECL_IGNORED_P (global_var) = 1; |
| TREE_READONLY (global_var) = 0; |
| DECL_EXTERNAL (global_var) = 1; |
| TREE_STATIC (global_var) = 1; |
| TREE_USED (global_var) = 1; |
| DECL_CONTEXT (global_var) = NULL_TREE; |
| TREE_THIS_VOLATILE (global_var) = 0; |
| TREE_ADDRESSABLE (global_var) = 0; |
| VAR_DECL_IS_VIRTUAL_OPERAND (global_var) = 1; |
| |
| fn->gimple_df->vop = global_var; |
| } |
| |
| /* These are the sizes of the operand memory buffer in bytes which gets |
| allocated each time more operands space is required. The final value is |
| the amount that is allocated every time after that. |
| In 1k we can fit 25 use operands (or 63 def operands) on a host with |
| 8 byte pointers, that would be 10 statements each with 1 def and 2 |
| uses. */ |
| |
| #define OP_SIZE_INIT 0 |
| #define OP_SIZE_1 (1024 - sizeof (void *)) |
| #define OP_SIZE_2 (1024 * 4 - sizeof (void *)) |
| #define OP_SIZE_3 (1024 * 16 - sizeof (void *)) |
| |
| /* Initialize the operand cache routines. */ |
| |
| void |
| init_ssa_operands (struct function *fn) |
| { |
| gcc_assert (gimple_ssa_operands (fn)->operand_memory == NULL); |
| gimple_ssa_operands (fn)->operand_memory_index |
| = gimple_ssa_operands (fn)->ssa_operand_mem_size; |
| gimple_ssa_operands (fn)->ops_active = true; |
| gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_INIT; |
| create_vop_var (fn); |
| } |
| |
| |
| /* Dispose of anything required by the operand routines. */ |
| |
| void |
| fini_ssa_operands (struct function *fn) |
| { |
| struct ssa_operand_memory_d *ptr; |
| |
| gimple_ssa_operands (fn)->free_uses = NULL; |
| |
| while ((ptr = gimple_ssa_operands (fn)->operand_memory) != NULL) |
| { |
| gimple_ssa_operands (fn)->operand_memory |
| = gimple_ssa_operands (fn)->operand_memory->next; |
| ggc_free (ptr); |
| } |
| |
| gimple_ssa_operands (fn)->ops_active = false; |
| |
| fn->gimple_df->vop = NULL_TREE; |
| } |
| |
| |
| /* Return memory for an operand of size SIZE. */ |
| |
| static inline void * |
| ssa_operand_alloc (struct function *fn, unsigned size) |
| { |
| char *ptr; |
| |
| gcc_assert (size == sizeof (struct use_optype_d)); |
| |
| if (gimple_ssa_operands (fn)->operand_memory_index + size |
| >= gimple_ssa_operands (fn)->ssa_operand_mem_size) |
| { |
| struct ssa_operand_memory_d *ptr; |
| |
| switch (gimple_ssa_operands (fn)->ssa_operand_mem_size) |
| { |
| case OP_SIZE_INIT: |
| gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_1; |
| break; |
| case OP_SIZE_1: |
| gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_2; |
| break; |
| case OP_SIZE_2: |
| case OP_SIZE_3: |
| gimple_ssa_operands (fn)->ssa_operand_mem_size = OP_SIZE_3; |
| break; |
| default: |
| gcc_unreachable (); |
| } |
| |
| |
| ptr = (ssa_operand_memory_d *) ggc_internal_alloc |
| (sizeof (void *) + gimple_ssa_operands (fn)->ssa_operand_mem_size); |
| |
| ptr->next = gimple_ssa_operands (fn)->operand_memory; |
| gimple_ssa_operands (fn)->operand_memory = ptr; |
| gimple_ssa_operands (fn)->operand_memory_index = 0; |
| } |
| |
| ptr = &(gimple_ssa_operands (fn)->operand_memory |
| ->mem[gimple_ssa_operands (fn)->operand_memory_index]); |
| gimple_ssa_operands (fn)->operand_memory_index += size; |
| return ptr; |
| } |
| |
| |
| /* Allocate a USE operand. */ |
| |
| static inline struct use_optype_d * |
| alloc_use (struct function *fn) |
| { |
| struct use_optype_d *ret; |
| if (gimple_ssa_operands (fn)->free_uses) |
| { |
| ret = gimple_ssa_operands (fn)->free_uses; |
| gimple_ssa_operands (fn)->free_uses |
| = gimple_ssa_operands (fn)->free_uses->next; |
| } |
| else |
| ret = (struct use_optype_d *) |
| ssa_operand_alloc (fn, sizeof (struct use_optype_d)); |
| return ret; |
| } |
| |
| |
| /* Adds OP to the list of uses of statement STMT after LAST. */ |
| |
| static inline use_optype_p |
| add_use_op (struct function *fn, gimple *stmt, tree *op, use_optype_p last) |
| { |
| use_optype_p new_use; |
| |
| new_use = alloc_use (fn); |
| USE_OP_PTR (new_use)->use = op; |
| link_imm_use_stmt (USE_OP_PTR (new_use), *op, stmt); |
| last->next = new_use; |
| new_use->next = NULL; |
| return new_use; |
| } |
| |
| |
| |
| /* Takes elements from build_defs and turns them into def operands of STMT. |
| TODO -- Make build_defs vec of tree *. */ |
| |
| inline void |
| operands_scanner::finalize_ssa_defs () |
| { |
| /* Pre-pend the vdef we may have built. */ |
| if (build_vdef != NULL_TREE) |
| { |
| tree oldvdef = gimple_vdef (stmt); |
| if (oldvdef |
| && TREE_CODE (oldvdef) == SSA_NAME) |
| oldvdef = SSA_NAME_VAR (oldvdef); |
| if (oldvdef != build_vdef) |
| gimple_set_vdef (stmt, build_vdef); |
| } |
| |
| /* Clear and unlink a no longer necessary VDEF. */ |
| if (build_vdef == NULL_TREE |
| && gimple_vdef (stmt) != NULL_TREE) |
| { |
| if (TREE_CODE (gimple_vdef (stmt)) == SSA_NAME) |
| { |
| unlink_stmt_vdef (stmt); |
| release_ssa_name_fn (fn, gimple_vdef (stmt)); |
| } |
| gimple_set_vdef (stmt, NULL_TREE); |
| } |
| |
| /* If we have a non-SSA_NAME VDEF, mark it for renaming. */ |
| if (gimple_vdef (stmt) |
| && TREE_CODE (gimple_vdef (stmt)) != SSA_NAME) |
| { |
| fn->gimple_df->rename_vops = 1; |
| fn->gimple_df->ssa_renaming_needed = 1; |
| } |
| } |
| |
| |
| /* Takes elements from build_uses and turns them into use operands of STMT. */ |
| |
| inline void |
| operands_scanner::finalize_ssa_uses () |
| { |
| unsigned new_i; |
| struct use_optype_d new_list; |
| use_optype_p old_ops, ptr, last; |
| |
| /* Pre-pend the VUSE we may have built. */ |
| if (build_vuse != NULL_TREE) |
| { |
| tree oldvuse = gimple_vuse (stmt); |
| if (oldvuse |
| && TREE_CODE (oldvuse) == SSA_NAME) |
| oldvuse = SSA_NAME_VAR (oldvuse); |
| if (oldvuse != (build_vuse != NULL_TREE |
| ? build_vuse : build_vdef)) |
| gimple_set_vuse (stmt, NULL_TREE); |
| build_uses.safe_insert (0, gimple_vuse_ptr (stmt)); |
| } |
| |
| new_list.next = NULL; |
| last = &new_list; |
| |
| old_ops = gimple_use_ops (stmt); |
| |
| /* Clear a no longer necessary VUSE. */ |
| if (build_vuse == NULL_TREE |
| && gimple_vuse (stmt) != NULL_TREE) |
| gimple_set_vuse (stmt, NULL_TREE); |
| |
| /* If there is anything in the old list, free it. */ |
| if (old_ops) |
| { |
| for (ptr = old_ops; ptr->next; ptr = ptr->next) |
| delink_imm_use (USE_OP_PTR (ptr)); |
| delink_imm_use (USE_OP_PTR (ptr)); |
| ptr->next = gimple_ssa_operands (fn)->free_uses; |
| gimple_ssa_operands (fn)->free_uses = old_ops; |
| } |
| |
| /* If we added a VUSE, make sure to set the operand if it is not already |
| present and mark it for renaming. */ |
| if (build_vuse != NULL_TREE |
| && gimple_vuse (stmt) == NULL_TREE) |
| { |
| gimple_set_vuse (stmt, gimple_vop (fn)); |
| fn->gimple_df->rename_vops = 1; |
| fn->gimple_df->ssa_renaming_needed = 1; |
| } |
| |
| /* Now create nodes for all the new nodes. */ |
| for (new_i = 0; new_i < build_uses.length (); new_i++) |
| { |
| tree *op = build_uses[new_i]; |
| last = add_use_op (fn, stmt, op, last); |
| } |
| |
| /* Now set the stmt's operands. */ |
| gimple_set_use_ops (stmt, new_list.next); |
| } |
| |
| |
| /* Clear the in_list bits and empty the build array for VDEFs and |
| VUSEs. */ |
| |
| inline void |
| operands_scanner::cleanup_build_arrays () |
| { |
| build_vdef = NULL_TREE; |
| build_vuse = NULL_TREE; |
| build_uses.truncate (0); |
| } |
| |
| |
| /* Finalize all the build vectors, fill the new ones into INFO. */ |
| |
| inline void |
| operands_scanner::finalize_ssa_stmt_operands () |
| { |
| finalize_ssa_defs (); |
| finalize_ssa_uses (); |
| cleanup_build_arrays (); |
| } |
| |
| |
| /* Start the process of building up operands vectors in INFO. */ |
| |
| inline void |
| operands_scanner::start_ssa_stmt_operands () |
| { |
| gcc_assert (build_uses.length () == 0); |
| gcc_assert (build_vuse == NULL_TREE); |
| gcc_assert (build_vdef == NULL_TREE); |
| } |
| |
| |
| /* Add USE_P to the list of pointers to operands. */ |
| |
| inline void |
| operands_scanner::append_use (tree *use_p) |
| { |
| build_uses.safe_push (use_p); |
| } |
| |
| |
| /* Add VAR to the set of variables that require a VDEF operator. */ |
| |
| inline void |
| operands_scanner::append_vdef (tree var) |
| { |
| gcc_assert ((build_vdef == NULL_TREE |
| || build_vdef == var) |
| && (build_vuse == NULL_TREE |
| || build_vuse == var)); |
| |
| build_vdef = var; |
| build_vuse = var; |
| } |
| |
| |
| /* Add VAR to the set of variables that require a VUSE operator. */ |
| |
| inline void |
| operands_scanner::append_vuse (tree var) |
| { |
| gcc_assert (build_vuse == NULL_TREE |
| || build_vuse == var); |
| |
| build_vuse = var; |
| } |
| |
| /* Add virtual operands for STMT. FLAGS is as in get_expr_operands. */ |
| |
| void |
| operands_scanner::add_virtual_operand (int flags) |
| { |
| /* Add virtual operands to the stmt, unless the caller has specifically |
| requested not to do that (used when adding operands inside an |
| ADDR_EXPR expression). */ |
| if (flags & opf_no_vops) |
| return; |
| |
| gcc_assert (!is_gimple_debug (stmt)); |
| |
| if (flags & opf_def) |
| append_vdef (gimple_vop (fn)); |
| else |
| append_vuse (gimple_vop (fn)); |
| } |
| |
| |
| /* Add *VAR_P to the appropriate operand array for statement STMT. |
| FLAGS is as in get_expr_operands. If *VAR_P is a GIMPLE register, |
| it will be added to the statement's real operands, otherwise it is |
| added to virtual operands. */ |
| |
| void |
| operands_scanner::add_stmt_operand (tree *var_p, int flags) |
| { |
| tree var = *var_p; |
| |
| gcc_assert (SSA_VAR_P (*var_p) |
| || TREE_CODE (*var_p) == STRING_CST |
| || TREE_CODE (*var_p) == CONST_DECL); |
| |
| if (is_gimple_reg (var)) |
| { |
| /* The variable is a GIMPLE register. Add it to real operands. */ |
| if (flags & opf_def) |
| ; |
| else |
| append_use (var_p); |
| if (DECL_P (*var_p)) |
| fn->gimple_df->ssa_renaming_needed = 1; |
| } |
| else |
| { |
| /* Mark statements with volatile operands. */ |
| if (!(flags & opf_no_vops) |
| && TREE_THIS_VOLATILE (var)) |
| gimple_set_has_volatile_ops (stmt, true); |
| |
| /* The variable is a memory access. Add virtual operands. */ |
| add_virtual_operand (flags); |
| } |
| } |
| |
| /* Mark the base address of REF as having its address taken. |
| REF may be a single variable whose address has been taken or any |
| other valid GIMPLE memory reference (structure reference, array, |
| etc). */ |
| |
| static void |
| mark_address_taken (tree ref) |
| { |
| tree var; |
| |
| /* Note that it is *NOT OKAY* to use the target of a COMPONENT_REF |
| as the only thing we take the address of. If VAR is a structure, |
| taking the address of a field means that the whole structure may |
| be referenced using pointer arithmetic. See PR 21407 and the |
| ensuing mailing list discussion. */ |
| var = get_base_address (ref); |
| if (VAR_P (var) |
| || TREE_CODE (var) == RESULT_DECL |
| || TREE_CODE (var) == PARM_DECL) |
| TREE_ADDRESSABLE (var) = 1; |
| } |
| |
| |
| /* A subroutine of get_expr_operands to handle MEM_REF. |
| |
| STMT is the statement being processed, EXPR is the MEM_REF |
| that got us here. |
| |
| FLAGS is as in get_expr_operands. */ |
| |
| void |
| operands_scanner::get_mem_ref_operands (tree expr, int flags) |
| { |
| tree *pptr = &TREE_OPERAND (expr, 0); |
| |
| if (!(flags & opf_no_vops) |
| && TREE_THIS_VOLATILE (expr)) |
| gimple_set_has_volatile_ops (stmt, true); |
| |
| /* Add the VOP. */ |
| add_virtual_operand (flags); |
| |
| /* If requested, add a USE operand for the base pointer. */ |
| get_expr_operands (pptr, |
| opf_non_addressable | opf_use |
| | (flags & (opf_no_vops|opf_not_non_addressable))); |
| } |
| |
| |
| /* A subroutine of get_expr_operands to handle TARGET_MEM_REF. */ |
| |
| void |
| operands_scanner::get_tmr_operands(tree expr, int flags) |
| { |
| if (!(flags & opf_no_vops) |
| && TREE_THIS_VOLATILE (expr)) |
| gimple_set_has_volatile_ops (stmt, true); |
| |
| /* First record the real operands. */ |
| get_expr_operands (&TMR_BASE (expr), |
| opf_non_addressable | opf_use |
| | (flags & (opf_no_vops|opf_not_non_addressable))); |
| get_expr_operands (&TMR_INDEX (expr), opf_use | (flags & opf_no_vops)); |
| get_expr_operands (&TMR_INDEX2 (expr), opf_use | (flags & opf_no_vops)); |
| |
| add_virtual_operand (flags); |
| } |
| |
| |
| /* If STMT is a call that may clobber globals and other symbols that |
| escape, add them to the VDEF/VUSE lists for it. */ |
| |
| void |
| operands_scanner::maybe_add_call_vops (gcall *stmt) |
| { |
| int call_flags = gimple_call_flags (stmt); |
| |
| /* If aliases have been computed already, add VDEF or VUSE |
| operands for all the symbols that have been found to be |
| call-clobbered. */ |
| if (!(call_flags & ECF_NOVOPS)) |
| { |
| /* A 'pure' or a 'const' function never call-clobbers anything. */ |
| if (!(call_flags & (ECF_PURE | ECF_CONST))) |
| add_virtual_operand (opf_def); |
| else if (!(call_flags & ECF_CONST)) |
| add_virtual_operand (opf_use); |
| } |
| } |
| |
| |
| /* Scan operands in the ASM_EXPR stmt referred to in INFO. */ |
| |
| void |
| operands_scanner::get_asm_stmt_operands (gasm *stmt) |
| { |
| size_t i, noutputs; |
| const char **oconstraints; |
| const char *constraint; |
| bool allows_mem, allows_reg, is_inout; |
| |
| noutputs = gimple_asm_noutputs (stmt); |
| oconstraints = (const char **) alloca ((noutputs) * sizeof (const char *)); |
| |
| /* Gather all output operands. */ |
| for (i = 0; i < gimple_asm_noutputs (stmt); i++) |
| { |
| tree link = gimple_asm_output_op (stmt, i); |
| constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); |
| oconstraints[i] = constraint; |
| parse_output_constraint (&constraint, i, 0, 0, &allows_mem, |
| &allows_reg, &is_inout); |
| |
| /* This should have been split in gimplify_asm_expr. */ |
| gcc_assert (!allows_reg || !is_inout); |
| |
| /* Memory operands are addressable. Note that STMT needs the |
| address of this operand. */ |
| if (!allows_reg && allows_mem) |
| mark_address_taken (TREE_VALUE (link)); |
| |
| get_expr_operands (&TREE_VALUE (link), opf_def | opf_not_non_addressable); |
| } |
| |
| /* Gather all input operands. */ |
| for (i = 0; i < gimple_asm_ninputs (stmt); i++) |
| { |
| tree link = gimple_asm_input_op (stmt, i); |
| constraint = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); |
| parse_input_constraint (&constraint, 0, 0, noutputs, 0, oconstraints, |
| &allows_mem, &allows_reg); |
| |
| /* Memory operands are addressable. Note that STMT needs the |
| address of this operand. */ |
| if (!allows_reg && allows_mem) |
| mark_address_taken (TREE_VALUE (link)); |
| |
| get_expr_operands (&TREE_VALUE (link), opf_not_non_addressable); |
| } |
| |
| /* Clobber all memory and addressable symbols for asm ("" : : : "memory"); */ |
| if (gimple_asm_clobbers_memory_p (stmt)) |
| add_virtual_operand (opf_def); |
| } |
| |
| |
| /* Recursively scan the expression pointed to by EXPR_P in statement |
| STMT. FLAGS is one of the OPF_* constants modifying how to |
| interpret the operands found. */ |
| |
| void |
| operands_scanner::get_expr_operands (tree *expr_p, int flags) |
| { |
| enum tree_code code; |
| enum tree_code_class codeclass; |
| tree expr = *expr_p; |
| int uflags = opf_use; |
| |
| if (expr == NULL) |
| return; |
| |
| if (is_gimple_debug (stmt)) |
| uflags |= (flags & opf_no_vops); |
| |
| code = TREE_CODE (expr); |
| codeclass = TREE_CODE_CLASS (code); |
| |
| switch (code) |
| { |
| case ADDR_EXPR: |
| /* Taking the address of a variable does not represent a |
| reference to it, but the fact that the statement takes its |
| address will be of interest to some passes (e.g. alias |
| resolution). */ |
| if ((!(flags & opf_non_addressable) |
| || (flags & opf_not_non_addressable)) |
| && !is_gimple_debug (stmt)) |
| mark_address_taken (TREE_OPERAND (expr, 0)); |
| |
| /* Otherwise, there may be variables referenced inside but there |
| should be no VUSEs created, since the referenced objects are |
| not really accessed. The only operands that we should find |
| here are ARRAY_REF indices which will always be real operands |
| (GIMPLE does not allow non-registers as array indices). */ |
| flags |= opf_no_vops; |
| get_expr_operands (&TREE_OPERAND (expr, 0), |
| flags | opf_not_non_addressable | opf_address_taken); |
| return; |
| |
| case SSA_NAME: |
| case VAR_DECL: |
| case PARM_DECL: |
| case RESULT_DECL: |
| case STRING_CST: |
| case CONST_DECL: |
| if (!(flags & opf_address_taken)) |
| add_stmt_operand (expr_p, flags); |
| return; |
| |
| case DEBUG_EXPR_DECL: |
| gcc_assert (gimple_debug_bind_p (stmt)); |
| return; |
| |
| case MEM_REF: |
| get_mem_ref_operands (expr, flags); |
| return; |
| |
| case TARGET_MEM_REF: |
| get_tmr_operands (expr, flags); |
| return; |
| |
| case ARRAY_REF: |
| case ARRAY_RANGE_REF: |
| case COMPONENT_REF: |
| case REALPART_EXPR: |
| case IMAGPART_EXPR: |
| { |
| if (!(flags & opf_no_vops) |
| && TREE_THIS_VOLATILE (expr)) |
| gimple_set_has_volatile_ops (stmt, true); |
| |
| get_expr_operands (&TREE_OPERAND (expr, 0), flags); |
| |
| if (code == COMPONENT_REF) |
| get_expr_operands (&TREE_OPERAND (expr, 2), uflags); |
| else if (code == ARRAY_REF || code == ARRAY_RANGE_REF) |
| { |
| get_expr_operands (&TREE_OPERAND (expr, 1), uflags); |
| get_expr_operands (&TREE_OPERAND (expr, 2), uflags); |
| get_expr_operands (&TREE_OPERAND (expr, 3), uflags); |
| } |
| |
| return; |
| } |
| |
| case WITH_SIZE_EXPR: |
| /* WITH_SIZE_EXPR is a pass-through reference to its first argument, |
| and an rvalue reference to its second argument. */ |
| get_expr_operands (&TREE_OPERAND (expr, 1), uflags); |
| get_expr_operands (&TREE_OPERAND (expr, 0), flags); |
| return; |
| |
| case COND_EXPR: |
| case VEC_COND_EXPR: |
| case VEC_PERM_EXPR: |
| get_expr_operands (&TREE_OPERAND (expr, 0), uflags); |
| get_expr_operands (&TREE_OPERAND (expr, 1), uflags); |
| get_expr_operands (&TREE_OPERAND (expr, 2), uflags); |
| return; |
| |
| case CONSTRUCTOR: |
| { |
| /* General aggregate CONSTRUCTORs have been decomposed, but they |
| are still in use as the COMPLEX_EXPR equivalent for vectors. */ |
| constructor_elt *ce; |
| unsigned HOST_WIDE_INT idx; |
| |
| /* A volatile constructor is actually TREE_CLOBBER_P, transfer |
| the volatility to the statement, don't use TREE_CLOBBER_P for |
| mirroring the other uses of THIS_VOLATILE in this file. */ |
| if (!(flags & opf_no_vops) |
| && TREE_THIS_VOLATILE (expr)) |
| gimple_set_has_volatile_ops (stmt, true); |
| |
| for (idx = 0; |
| vec_safe_iterate (CONSTRUCTOR_ELTS (expr), idx, &ce); |
| idx++) |
| get_expr_operands (&ce->value, uflags); |
| |
| return; |
| } |
| |
| case BIT_FIELD_REF: |
| if (!(flags & opf_no_vops) |
| && TREE_THIS_VOLATILE (expr)) |
| gimple_set_has_volatile_ops (stmt, true); |
| /* FALLTHRU */ |
| |
| case VIEW_CONVERT_EXPR: |
| do_unary: |
| get_expr_operands (&TREE_OPERAND (expr, 0), flags); |
| return; |
| |
| case BIT_INSERT_EXPR: |
| case COMPOUND_EXPR: |
| case OBJ_TYPE_REF: |
| do_binary: |
| { |
| get_expr_operands (&TREE_OPERAND (expr, 0), flags); |
| get_expr_operands (&TREE_OPERAND (expr, 1), flags); |
| return; |
| } |
| |
| case DOT_PROD_EXPR: |
| case SAD_EXPR: |
| case REALIGN_LOAD_EXPR: |
| case WIDEN_MULT_PLUS_EXPR: |
| case WIDEN_MULT_MINUS_EXPR: |
| { |
| get_expr_operands (&TREE_OPERAND (expr, 0), flags); |
| get_expr_operands (&TREE_OPERAND (expr, 1), flags); |
| get_expr_operands (&TREE_OPERAND (expr, 2), flags); |
| return; |
| } |
| |
| case FUNCTION_DECL: |
| case LABEL_DECL: |
| case CASE_LABEL_EXPR: |
| /* Expressions that make no memory references. */ |
| return; |
| |
| default: |
| if (codeclass == tcc_unary) |
| goto do_unary; |
| if (codeclass == tcc_binary || codeclass == tcc_comparison) |
| goto do_binary; |
| if (codeclass == tcc_constant || codeclass == tcc_type) |
| return; |
| } |
| |
| /* If we get here, something has gone wrong. */ |
| if (flag_checking) |
| { |
| fprintf (stderr, "unhandled expression in get_expr_operands():\n"); |
| debug_tree (expr); |
| fputs ("\n", stderr); |
| gcc_unreachable (); |
| } |
| } |
| |
| |
| /* Parse STMT looking for operands. When finished, the various |
| build_* operand vectors will have potential operands in them. */ |
| |
| void |
| operands_scanner::parse_ssa_operands () |
| { |
| enum gimple_code code = gimple_code (stmt); |
| size_t i, n, start = 0; |
| |
| switch (code) |
| { |
| case GIMPLE_ASM: |
| get_asm_stmt_operands (as_a <gasm *> (stmt)); |
| break; |
| |
| case GIMPLE_TRANSACTION: |
| /* The start of a transaction is a memory barrier. */ |
| add_virtual_operand (opf_def | opf_use); |
| break; |
| |
| case GIMPLE_DEBUG: |
| if (gimple_debug_bind_p (stmt) |
| && gimple_debug_bind_has_value_p (stmt)) |
| get_expr_operands (gimple_debug_bind_get_value_ptr (stmt), |
| opf_use | opf_no_vops); |
| break; |
| |
| case GIMPLE_RETURN: |
| append_vuse (gimple_vop (fn)); |
| goto do_default; |
| |
| case GIMPLE_CALL: |
| /* Add call-clobbered operands, if needed. */ |
| maybe_add_call_vops (as_a <gcall *> (stmt)); |
| /* FALLTHRU */ |
| |
| case GIMPLE_ASSIGN: |
| get_expr_operands (gimple_op_ptr (stmt, 0), opf_def); |
| start = 1; |
| /* FALLTHRU */ |
| |
| default: |
| do_default: |
| n = gimple_num_ops (stmt); |
| for (i = start; i < n; i++) |
| get_expr_operands (gimple_op_ptr (stmt, i), opf_use); |
| break; |
| } |
| } |
| |
| |
| /* Create an operands cache for STMT. */ |
| |
| void |
| operands_scanner::build_ssa_operands () |
| { |
| /* Initially assume that the statement has no volatile operands. */ |
| gimple_set_has_volatile_ops (stmt, false); |
| |
| start_ssa_stmt_operands (); |
| parse_ssa_operands (); |
| finalize_ssa_stmt_operands (); |
| } |
| |
| /* Verifies SSA statement operands. */ |
| |
| DEBUG_FUNCTION bool |
| operands_scanner::verify_ssa_operands () |
| { |
| use_operand_p use_p; |
| def_operand_p def_p; |
| ssa_op_iter iter; |
| unsigned i; |
| tree def; |
| bool volatile_p = gimple_has_volatile_ops (stmt); |
| |
| /* build_ssa_operands w/o finalizing them. */ |
| gimple_set_has_volatile_ops (stmt, false); |
| start_ssa_stmt_operands (); |
| parse_ssa_operands (); |
| |
| /* Now verify the built operands are the same as present in STMT. */ |
| def = gimple_vdef (stmt); |
| if (def |
| && TREE_CODE (def) == SSA_NAME) |
| def = SSA_NAME_VAR (def); |
| if (build_vdef != def) |
| { |
| error ("virtual definition of statement not up to date"); |
| return true; |
| } |
| if (gimple_vdef (stmt) |
| && ((def_p = gimple_vdef_op (stmt)) == NULL_DEF_OPERAND_P |
| || DEF_FROM_PTR (def_p) != gimple_vdef (stmt))) |
| { |
| error ("virtual def operand missing for statement"); |
| return true; |
| } |
| |
| tree use = gimple_vuse (stmt); |
| if (use |
| && TREE_CODE (use) == SSA_NAME) |
| use = SSA_NAME_VAR (use); |
| if (build_vuse != use) |
| { |
| error ("virtual use of statement not up to date"); |
| return true; |
| } |
| if (gimple_vuse (stmt) |
| && ((use_p = gimple_vuse_op (stmt)) == NULL_USE_OPERAND_P |
| || USE_FROM_PTR (use_p) != gimple_vuse (stmt))) |
| { |
| error ("virtual use operand missing for statement"); |
| return true; |
| } |
| |
| FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE) |
| { |
| tree *op; |
| FOR_EACH_VEC_ELT (build_uses, i, op) |
| { |
| if (use_p->use == op) |
| { |
| build_uses[i] = NULL; |
| break; |
| } |
| } |
| if (i == build_uses.length ()) |
| { |
| error ("excess use operand for statement"); |
| debug_generic_expr (USE_FROM_PTR (use_p)); |
| return true; |
| } |
| } |
| |
| tree *op; |
| FOR_EACH_VEC_ELT (build_uses, i, op) |
| if (op != NULL) |
| { |
| error ("use operand missing for statement"); |
| debug_generic_expr (*op); |
| return true; |
| } |
| |
| if (gimple_has_volatile_ops (stmt) != volatile_p) |
| { |
| error ("statement volatile flag not up to date"); |
| return true; |
| } |
| |
| cleanup_build_arrays (); |
| return false; |
| } |
| |
| /* Interface for external use. */ |
| |
| DEBUG_FUNCTION bool |
| verify_ssa_operands (struct function *fn, gimple *stmt) |
| { |
| return operands_scanner (fn, stmt).verify_ssa_operands (); |
| } |
| |
| |
| /* Releases the operands of STMT back to their freelists, and clears |
| the stmt operand lists. */ |
| |
| void |
| free_stmt_operands (struct function *fn, gimple *stmt) |
| { |
| use_optype_p uses = gimple_use_ops (stmt), last_use; |
| |
| if (uses) |
| { |
| for (last_use = uses; last_use->next; last_use = last_use->next) |
| delink_imm_use (USE_OP_PTR (last_use)); |
| delink_imm_use (USE_OP_PTR (last_use)); |
| last_use->next = gimple_ssa_operands (fn)->free_uses; |
| gimple_ssa_operands (fn)->free_uses = uses; |
| gimple_set_use_ops (stmt, NULL); |
| } |
| |
| if (gimple_has_mem_ops (stmt)) |
| { |
| gimple_set_vuse (stmt, NULL_TREE); |
| gimple_set_vdef (stmt, NULL_TREE); |
| } |
| } |
| |
| |
| /* Get the operands of statement STMT. */ |
| |
| void |
| update_stmt_operands (struct function *fn, gimple *stmt) |
| { |
| /* If update_stmt_operands is called before SSA is initialized, do |
| nothing. */ |
| if (!ssa_operands_active (fn)) |
| return; |
| |
| timevar_push (TV_TREE_OPS); |
| |
| gcc_assert (gimple_modified_p (stmt)); |
| operands_scanner (fn, stmt).build_ssa_operands (); |
| gimple_set_modified (stmt, false); |
| // Inform the active range query an update has happened. |
| get_range_query (fn)->update_stmt (stmt); |
| |
| timevar_pop (TV_TREE_OPS); |
| } |
| |
| |
| /* Swap operands EXP0 and EXP1 in statement STMT. No attempt is done |
| to test the validity of the swap operation. */ |
| |
| void |
| swap_ssa_operands (gimple *stmt, tree *exp0, tree *exp1) |
| { |
| tree op0, op1; |
| op0 = *exp0; |
| op1 = *exp1; |
| |
| if (op0 != op1) |
| { |
| /* Attempt to preserve the relative positions of these two operands in |
| their * respective immediate use lists by adjusting their use pointer |
| to point to the new operand position. */ |
| use_optype_p use0, use1, ptr; |
| use0 = use1 = NULL; |
| |
| /* Find the 2 operands in the cache, if they are there. */ |
| for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next) |
| if (USE_OP_PTR (ptr)->use == exp0) |
| { |
| use0 = ptr; |
| break; |
| } |
| |
| for (ptr = gimple_use_ops (stmt); ptr; ptr = ptr->next) |
| if (USE_OP_PTR (ptr)->use == exp1) |
| { |
| use1 = ptr; |
| break; |
| } |
| |
| /* And adjust their location to point to the new position of the |
| operand. */ |
| if (use0) |
| USE_OP_PTR (use0)->use = exp1; |
| if (use1) |
| USE_OP_PTR (use1)->use = exp0; |
| |
| /* Now swap the data. */ |
| *exp0 = op1; |
| *exp1 = op0; |
| } |
| } |
| |
| |
| /* Scan the immediate_use list for VAR making sure its linked properly. |
| Return TRUE if there is a problem and emit an error message to F. */ |
| |
| DEBUG_FUNCTION bool |
| verify_imm_links (FILE *f, tree var) |
| { |
| use_operand_p ptr, prev, list; |
| unsigned int count; |
| |
| gcc_assert (TREE_CODE (var) == SSA_NAME); |
| |
| list = &(SSA_NAME_IMM_USE_NODE (var)); |
| gcc_assert (list->use == NULL); |
| |
| if (list->prev == NULL) |
| { |
| gcc_assert (list->next == NULL); |
| return false; |
| } |
| |
| prev = list; |
| count = 0; |
| for (ptr = list->next; ptr != list; ) |
| { |
| if (prev != ptr->prev) |
| { |
| fprintf (f, "prev != ptr->prev\n"); |
| goto error; |
| } |
| |
| if (ptr->use == NULL) |
| { |
| fprintf (f, "ptr->use == NULL\n"); |
| goto error; /* 2 roots, or SAFE guard node. */ |
| } |
| else if (*(ptr->use) != var) |
| { |
| fprintf (f, "*(ptr->use) != var\n"); |
| goto error; |
| } |
| |
| prev = ptr; |
| ptr = ptr->next; |
| |
| count++; |
| if (count == 0) |
| { |
| fprintf (f, "number of immediate uses doesn't fit unsigned int\n"); |
| goto error; |
| } |
| } |
| |
| /* Verify list in the other direction. */ |
| prev = list; |
| for (ptr = list->prev; ptr != list; ) |
| { |
| if (prev != ptr->next) |
| { |
| fprintf (f, "prev != ptr->next\n"); |
| goto error; |
| } |
| prev = ptr; |
| ptr = ptr->prev; |
| if (count == 0) |
| { |
| fprintf (f, "count-- < 0\n"); |
| goto error; |
| } |
| count--; |
| } |
| |
| if (count != 0) |
| { |
| fprintf (f, "count != 0\n"); |
| goto error; |
| } |
| |
| return false; |
| |
| error: |
| if (ptr->loc.stmt && gimple_modified_p (ptr->loc.stmt)) |
| { |
| fprintf (f, " STMT MODIFIED. - <%p> ", (void *)ptr->loc.stmt); |
| print_gimple_stmt (f, ptr->loc.stmt, 0, TDF_SLIM); |
| } |
| fprintf (f, " IMM ERROR : (use_p : tree - %p:%p)", (void *)ptr, |
| (void *)ptr->use); |
| print_generic_expr (f, USE_FROM_PTR (ptr), TDF_SLIM); |
| fprintf (f, "\n"); |
| return true; |
| } |
| |
| |
| /* Dump all the immediate uses to FILE. */ |
| |
| void |
| dump_immediate_uses_for (FILE *file, tree var) |
| { |
| imm_use_iterator iter; |
| use_operand_p use_p; |
| |
| gcc_assert (var && TREE_CODE (var) == SSA_NAME); |
| |
| print_generic_expr (file, var, TDF_SLIM); |
| fprintf (file, " : -->"); |
| if (has_zero_uses (var)) |
| fprintf (file, " no uses.\n"); |
| else |
| if (has_single_use (var)) |
| fprintf (file, " single use.\n"); |
| else |
| fprintf (file, "%d uses.\n", num_imm_uses (var)); |
| |
| FOR_EACH_IMM_USE_FAST (use_p, iter, var) |
| { |
| if (use_p->loc.stmt == NULL && use_p->use == NULL) |
| fprintf (file, "***end of stmt iterator marker***\n"); |
| else |
| if (!is_gimple_reg (USE_FROM_PTR (use_p))) |
| print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_VOPS|TDF_MEMSYMS); |
| else |
| print_gimple_stmt (file, USE_STMT (use_p), 0, TDF_SLIM); |
| } |
| fprintf (file, "\n"); |
| } |
| |
| |
| /* Dump all the immediate uses to FILE. */ |
| |
| void |
| dump_immediate_uses (FILE *file) |
| { |
| tree var; |
| unsigned int x; |
| |
| fprintf (file, "Immediate_uses: \n\n"); |
| FOR_EACH_SSA_NAME (x, var, cfun) |
| { |
| dump_immediate_uses_for (file, var); |
| } |
| } |
| |
| |
| /* Dump def-use edges on stderr. */ |
| |
| DEBUG_FUNCTION void |
| debug_immediate_uses (void) |
| { |
| dump_immediate_uses (stderr); |
| } |
| |
| |
| /* Dump def-use edges on stderr. */ |
| |
| DEBUG_FUNCTION void |
| debug_immediate_uses_for (tree var) |
| { |
| dump_immediate_uses_for (stderr, var); |
| } |
| |
| |
| /* Unlink STMTs virtual definition from the IL by propagating its use. */ |
| |
| void |
| unlink_stmt_vdef (gimple *stmt) |
| { |
| use_operand_p use_p; |
| imm_use_iterator iter; |
| gimple *use_stmt; |
| tree vdef = gimple_vdef (stmt); |
| tree vuse = gimple_vuse (stmt); |
| |
| if (!vdef |
| || TREE_CODE (vdef) != SSA_NAME) |
| return; |
| |
| FOR_EACH_IMM_USE_STMT (use_stmt, iter, vdef) |
| { |
| FOR_EACH_IMM_USE_ON_STMT (use_p, iter) |
| SET_USE (use_p, vuse); |
| } |
| |
| if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vdef)) |
| SSA_NAME_OCCURS_IN_ABNORMAL_PHI (vuse) = 1; |
| } |
| |
| /* Return true if the var whose chain of uses starts at PTR has a |
| single nondebug use. Set USE_P and STMT to that single nondebug |
| use, if so, or to NULL otherwise. */ |
| bool |
| single_imm_use_1 (const ssa_use_operand_t *head, |
| use_operand_p *use_p, gimple **stmt) |
| { |
| ssa_use_operand_t *ptr, *single_use = 0; |
| |
| for (ptr = head->next; ptr != head; ptr = ptr->next) |
| if (USE_STMT(ptr) && !is_gimple_debug (USE_STMT (ptr))) |
| { |
| if (single_use) |
| { |
| single_use = NULL; |
| break; |
| } |
| single_use = ptr; |
| } |
| |
| if (use_p) |
| *use_p = single_use; |
| |
| if (stmt) |
| *stmt = single_use ? single_use->loc.stmt : NULL; |
| |
| return single_use; |
| } |
| |