| /* __builtin_object_size (ptr, object_size_type) computation |
| Copyright (C) 2004-2020 Free Software Foundation, Inc. |
| Contributed by Jakub Jelinek <jakub@redhat.com> |
| |
| 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 "tree-pass.h" |
| #include "ssa.h" |
| #include "gimple-pretty-print.h" |
| #include "fold-const.h" |
| #include "tree-object-size.h" |
| #include "gimple-fold.h" |
| #include "gimple-iterator.h" |
| #include "tree-cfg.h" |
| #include "stringpool.h" |
| #include "attribs.h" |
| |
| struct object_size_info |
| { |
| int object_size_type; |
| unsigned char pass; |
| bool changed; |
| bitmap visited, reexamine; |
| unsigned int *depths; |
| unsigned int *stack, *tos; |
| }; |
| |
| static const unsigned HOST_WIDE_INT unknown[4] = { |
| HOST_WIDE_INT_M1U, |
| HOST_WIDE_INT_M1U, |
| 0, |
| 0 |
| }; |
| |
| static tree compute_object_offset (const_tree, const_tree); |
| static bool addr_object_size (struct object_size_info *, |
| const_tree, int, unsigned HOST_WIDE_INT *, |
| tree * = NULL, tree * = NULL); |
| static unsigned HOST_WIDE_INT alloc_object_size (const gcall *, int); |
| static tree pass_through_call (const gcall *); |
| static void collect_object_sizes_for (struct object_size_info *, tree); |
| static void expr_object_size (struct object_size_info *, tree, tree); |
| static bool merge_object_sizes (struct object_size_info *, tree, tree, |
| unsigned HOST_WIDE_INT); |
| static bool plus_stmt_object_size (struct object_size_info *, tree, gimple *); |
| static bool cond_expr_object_size (struct object_size_info *, tree, gimple *); |
| static void init_offset_limit (void); |
| static void check_for_plus_in_loops (struct object_size_info *, tree); |
| static void check_for_plus_in_loops_1 (struct object_size_info *, tree, |
| unsigned int); |
| |
| /* object_sizes[0] is upper bound for number of bytes till the end of |
| the object. |
| object_sizes[1] is upper bound for number of bytes till the end of |
| the subobject (innermost array or field with address taken). |
| object_sizes[2] is lower bound for number of bytes till the end of |
| the object and object_sizes[3] lower bound for subobject. */ |
| static vec<unsigned HOST_WIDE_INT> object_sizes[4]; |
| |
| /* Bitmaps what object sizes have been computed already. */ |
| static bitmap computed[4]; |
| |
| /* Maximum value of offset we consider to be addition. */ |
| static unsigned HOST_WIDE_INT offset_limit; |
| |
| |
| /* Initialize OFFSET_LIMIT variable. */ |
| static void |
| init_offset_limit (void) |
| { |
| if (tree_fits_uhwi_p (TYPE_MAX_VALUE (sizetype))) |
| offset_limit = tree_to_uhwi (TYPE_MAX_VALUE (sizetype)); |
| else |
| offset_limit = -1; |
| offset_limit /= 2; |
| } |
| |
| |
| /* Compute offset of EXPR within VAR. Return error_mark_node |
| if unknown. */ |
| |
| static tree |
| compute_object_offset (const_tree expr, const_tree var) |
| { |
| enum tree_code code = PLUS_EXPR; |
| tree base, off, t; |
| |
| if (expr == var) |
| return size_zero_node; |
| |
| switch (TREE_CODE (expr)) |
| { |
| case COMPONENT_REF: |
| base = compute_object_offset (TREE_OPERAND (expr, 0), var); |
| if (base == error_mark_node) |
| return base; |
| |
| t = TREE_OPERAND (expr, 1); |
| off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t), |
| size_int (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (t)) |
| / BITS_PER_UNIT)); |
| break; |
| |
| case REALPART_EXPR: |
| CASE_CONVERT: |
| case VIEW_CONVERT_EXPR: |
| case NON_LVALUE_EXPR: |
| return compute_object_offset (TREE_OPERAND (expr, 0), var); |
| |
| case IMAGPART_EXPR: |
| base = compute_object_offset (TREE_OPERAND (expr, 0), var); |
| if (base == error_mark_node) |
| return base; |
| |
| off = TYPE_SIZE_UNIT (TREE_TYPE (expr)); |
| break; |
| |
| case ARRAY_REF: |
| base = compute_object_offset (TREE_OPERAND (expr, 0), var); |
| if (base == error_mark_node) |
| return base; |
| |
| t = TREE_OPERAND (expr, 1); |
| tree low_bound, unit_size; |
| low_bound = array_ref_low_bound (CONST_CAST_TREE (expr)); |
| unit_size = array_ref_element_size (CONST_CAST_TREE (expr)); |
| if (! integer_zerop (low_bound)) |
| t = fold_build2 (MINUS_EXPR, TREE_TYPE (t), t, low_bound); |
| if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0) |
| { |
| code = MINUS_EXPR; |
| t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t); |
| } |
| t = fold_convert (sizetype, t); |
| off = size_binop (MULT_EXPR, unit_size, t); |
| break; |
| |
| case MEM_REF: |
| gcc_assert (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR); |
| return wide_int_to_tree (sizetype, mem_ref_offset (expr)); |
| |
| default: |
| return error_mark_node; |
| } |
| |
| return size_binop (code, base, off); |
| } |
| |
| |
| /* Compute __builtin_object_size for PTR, which is a ADDR_EXPR. |
| OBJECT_SIZE_TYPE is the second argument from __builtin_object_size. |
| If unknown, return unknown[object_size_type]. */ |
| |
| static bool |
| addr_object_size (struct object_size_info *osi, const_tree ptr, |
| int object_size_type, unsigned HOST_WIDE_INT *psize, |
| tree *pdecl /* = NULL */, tree *poff /* = NULL */) |
| { |
| tree pt_var, pt_var_size = NULL_TREE, var_size, bytes; |
| |
| tree dummy_decl, dummy_off = size_zero_node; |
| if (!pdecl) |
| pdecl = &dummy_decl; |
| if (!poff) |
| poff = &dummy_off; |
| |
| gcc_assert (TREE_CODE (ptr) == ADDR_EXPR); |
| |
| /* Set to unknown and overwrite just before returning if the size |
| could be determined. */ |
| *psize = unknown[object_size_type]; |
| |
| pt_var = TREE_OPERAND (ptr, 0); |
| while (handled_component_p (pt_var)) |
| pt_var = TREE_OPERAND (pt_var, 0); |
| |
| if (pt_var |
| && TREE_CODE (pt_var) == MEM_REF) |
| { |
| unsigned HOST_WIDE_INT sz; |
| |
| if (!osi || (object_size_type & 1) != 0 |
| || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME) |
| { |
| compute_builtin_object_size (TREE_OPERAND (pt_var, 0), |
| object_size_type & ~1, &sz, pdecl, poff); |
| } |
| else |
| { |
| tree var = TREE_OPERAND (pt_var, 0); |
| if (osi->pass == 0) |
| collect_object_sizes_for (osi, var); |
| if (bitmap_bit_p (computed[object_size_type], |
| SSA_NAME_VERSION (var))) |
| sz = object_sizes[object_size_type][SSA_NAME_VERSION (var)]; |
| else |
| sz = unknown[object_size_type]; |
| } |
| if (sz != unknown[object_size_type]) |
| { |
| offset_int mem_offset; |
| if (mem_ref_offset (pt_var).is_constant (&mem_offset)) |
| { |
| offset_int dsz = wi::sub (sz, mem_offset); |
| if (wi::neg_p (dsz)) |
| sz = 0; |
| else if (wi::fits_uhwi_p (dsz)) |
| sz = dsz.to_uhwi (); |
| else |
| sz = unknown[object_size_type]; |
| } |
| else |
| sz = unknown[object_size_type]; |
| } |
| |
| if (sz != unknown[object_size_type] && sz < offset_limit) |
| pt_var_size = size_int (sz); |
| } |
| else if (pt_var |
| && DECL_P (pt_var) |
| && tree_fits_uhwi_p (DECL_SIZE_UNIT (pt_var)) |
| && tree_to_uhwi (DECL_SIZE_UNIT (pt_var)) < offset_limit) |
| { |
| *pdecl = pt_var; |
| pt_var_size = DECL_SIZE_UNIT (pt_var); |
| } |
| else if (pt_var |
| && TREE_CODE (pt_var) == STRING_CST |
| && TYPE_SIZE_UNIT (TREE_TYPE (pt_var)) |
| && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (pt_var))) |
| && tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (pt_var))) |
| < offset_limit) |
| pt_var_size = TYPE_SIZE_UNIT (TREE_TYPE (pt_var)); |
| else |
| return false; |
| |
| if (pt_var != TREE_OPERAND (ptr, 0)) |
| { |
| tree var; |
| |
| if (object_size_type & 1) |
| { |
| var = TREE_OPERAND (ptr, 0); |
| |
| while (var != pt_var |
| && TREE_CODE (var) != BIT_FIELD_REF |
| && TREE_CODE (var) != COMPONENT_REF |
| && TREE_CODE (var) != ARRAY_REF |
| && TREE_CODE (var) != ARRAY_RANGE_REF |
| && TREE_CODE (var) != REALPART_EXPR |
| && TREE_CODE (var) != IMAGPART_EXPR) |
| var = TREE_OPERAND (var, 0); |
| if (var != pt_var && TREE_CODE (var) == ARRAY_REF) |
| var = TREE_OPERAND (var, 0); |
| if (! TYPE_SIZE_UNIT (TREE_TYPE (var)) |
| || ! tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (var))) |
| || (pt_var_size |
| && tree_int_cst_lt (pt_var_size, |
| TYPE_SIZE_UNIT (TREE_TYPE (var))))) |
| var = pt_var; |
| else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF) |
| { |
| tree v = var; |
| /* For &X->fld, compute object size only if fld isn't the last |
| field, as struct { int i; char c[1]; } is often used instead |
| of flexible array member. */ |
| while (v && v != pt_var) |
| switch (TREE_CODE (v)) |
| { |
| case ARRAY_REF: |
| if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0))) |
| && TREE_CODE (TREE_OPERAND (v, 1)) == INTEGER_CST) |
| { |
| tree domain |
| = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0))); |
| if (domain |
| && TYPE_MAX_VALUE (domain) |
| && TREE_CODE (TYPE_MAX_VALUE (domain)) |
| == INTEGER_CST |
| && tree_int_cst_lt (TREE_OPERAND (v, 1), |
| TYPE_MAX_VALUE (domain))) |
| { |
| v = NULL_TREE; |
| break; |
| } |
| } |
| v = TREE_OPERAND (v, 0); |
| break; |
| case REALPART_EXPR: |
| case IMAGPART_EXPR: |
| v = NULL_TREE; |
| break; |
| case COMPONENT_REF: |
| if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE) |
| { |
| v = NULL_TREE; |
| break; |
| } |
| while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
| if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) |
| != UNION_TYPE |
| && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) |
| != QUAL_UNION_TYPE) |
| break; |
| else |
| v = TREE_OPERAND (v, 0); |
| if (TREE_CODE (v) == COMPONENT_REF |
| && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) |
| == RECORD_TYPE) |
| { |
| tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1)); |
| for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain)) |
| if (TREE_CODE (fld_chain) == FIELD_DECL) |
| break; |
| |
| if (fld_chain) |
| { |
| v = NULL_TREE; |
| break; |
| } |
| v = TREE_OPERAND (v, 0); |
| } |
| while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
| if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) |
| != UNION_TYPE |
| && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) |
| != QUAL_UNION_TYPE) |
| break; |
| else |
| v = TREE_OPERAND (v, 0); |
| if (v != pt_var) |
| v = NULL_TREE; |
| else |
| v = pt_var; |
| break; |
| default: |
| v = pt_var; |
| break; |
| } |
| if (v == pt_var) |
| var = pt_var; |
| } |
| } |
| else |
| var = pt_var; |
| |
| if (var != pt_var) |
| var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); |
| else if (!pt_var_size) |
| return false; |
| else |
| var_size = pt_var_size; |
| bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var); |
| if (bytes != error_mark_node) |
| { |
| if (TREE_CODE (bytes) == INTEGER_CST |
| && tree_int_cst_lt (var_size, bytes)) |
| bytes = size_zero_node; |
| else |
| bytes = size_binop (MINUS_EXPR, var_size, bytes); |
| *poff = bytes; |
| } |
| if (var != pt_var |
| && pt_var_size |
| && TREE_CODE (pt_var) == MEM_REF |
| && bytes != error_mark_node) |
| { |
| tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0), pt_var); |
| if (bytes2 != error_mark_node) |
| { |
| if (TREE_CODE (bytes2) == INTEGER_CST |
| && tree_int_cst_lt (pt_var_size, bytes2)) |
| bytes2 = size_zero_node; |
| else |
| bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2); |
| *poff = size_binop (PLUS_EXPR, *poff, bytes2); |
| bytes = size_binop (MIN_EXPR, bytes, bytes2); |
| } |
| } |
| } |
| else if (!pt_var_size) |
| return false; |
| else |
| bytes = pt_var_size; |
| |
| if (tree_fits_uhwi_p (bytes)) |
| { |
| *psize = tree_to_uhwi (bytes); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| |
| /* Compute __builtin_object_size for CALL, which is a GIMPLE_CALL. |
| Handles calls to functions declared with attribute alloc_size. |
| OBJECT_SIZE_TYPE is the second argument from __builtin_object_size. |
| If unknown, return unknown[object_size_type]. */ |
| |
| static unsigned HOST_WIDE_INT |
| alloc_object_size (const gcall *call, int object_size_type) |
| { |
| gcc_assert (is_gimple_call (call)); |
| |
| tree calltype; |
| if (tree callfn = gimple_call_fndecl (call)) |
| calltype = TREE_TYPE (callfn); |
| else |
| calltype = gimple_call_fntype (call); |
| |
| if (!calltype) |
| return unknown[object_size_type]; |
| |
| /* Set to positions of alloc_size arguments. */ |
| int arg1 = -1, arg2 = -1; |
| tree alloc_size = lookup_attribute ("alloc_size", |
| TYPE_ATTRIBUTES (calltype)); |
| if (alloc_size && TREE_VALUE (alloc_size)) |
| { |
| tree p = TREE_VALUE (alloc_size); |
| |
| arg1 = TREE_INT_CST_LOW (TREE_VALUE (p))-1; |
| if (TREE_CHAIN (p)) |
| arg2 = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (p)))-1; |
| } |
| |
| if (arg1 < 0 || arg1 >= (int)gimple_call_num_args (call) |
| || TREE_CODE (gimple_call_arg (call, arg1)) != INTEGER_CST |
| || (arg2 >= 0 |
| && (arg2 >= (int)gimple_call_num_args (call) |
| || TREE_CODE (gimple_call_arg (call, arg2)) != INTEGER_CST))) |
| return unknown[object_size_type]; |
| |
| tree bytes = NULL_TREE; |
| if (arg2 >= 0) |
| bytes = size_binop (MULT_EXPR, |
| fold_convert (sizetype, gimple_call_arg (call, arg1)), |
| fold_convert (sizetype, gimple_call_arg (call, arg2))); |
| else if (arg1 >= 0) |
| bytes = fold_convert (sizetype, gimple_call_arg (call, arg1)); |
| |
| if (bytes && tree_fits_uhwi_p (bytes)) |
| return tree_to_uhwi (bytes); |
| |
| return unknown[object_size_type]; |
| } |
| |
| |
| /* If object size is propagated from one of function's arguments directly |
| to its return value, return that argument for GIMPLE_CALL statement CALL. |
| Otherwise return NULL. */ |
| |
| static tree |
| pass_through_call (const gcall *call) |
| { |
| unsigned rf = gimple_call_return_flags (call); |
| if (rf & ERF_RETURNS_ARG) |
| { |
| unsigned argnum = rf & ERF_RETURN_ARG_MASK; |
| if (argnum < gimple_call_num_args (call)) |
| return gimple_call_arg (call, argnum); |
| } |
| |
| /* __builtin_assume_aligned is intentionally not marked RET1. */ |
| if (gimple_call_builtin_p (call, BUILT_IN_ASSUME_ALIGNED)) |
| return gimple_call_arg (call, 0); |
| |
| return NULL_TREE; |
| } |
| |
| |
| /* Compute __builtin_object_size value for PTR and set *PSIZE to |
| the resulting value. If the declared object is known and PDECL |
| is nonnull, sets *PDECL to the object's DECL. OBJECT_SIZE_TYPE |
| is the second argument to __builtin_object_size. |
| Returns true on success and false when the object size could not |
| be determined. */ |
| |
| bool |
| compute_builtin_object_size (tree ptr, int object_size_type, |
| unsigned HOST_WIDE_INT *psize, |
| tree *pdecl /* = NULL */, tree *poff /* = NULL */) |
| { |
| gcc_assert (object_size_type >= 0 && object_size_type <= 3); |
| |
| tree dummy_decl, dummy_off = size_zero_node; |
| if (!pdecl) |
| pdecl = &dummy_decl; |
| if (!poff) |
| poff = &dummy_off; |
| |
| /* Set to unknown and overwrite just before returning if the size |
| could be determined. */ |
| *psize = unknown[object_size_type]; |
| |
| if (! offset_limit) |
| init_offset_limit (); |
| |
| if (TREE_CODE (ptr) == ADDR_EXPR) |
| return addr_object_size (NULL, ptr, object_size_type, psize, pdecl, poff); |
| |
| if (TREE_CODE (ptr) != SSA_NAME |
| || !POINTER_TYPE_P (TREE_TYPE (ptr))) |
| return false; |
| |
| if (computed[object_size_type] == NULL) |
| { |
| if (optimize || object_size_type & 1) |
| return false; |
| |
| /* When not optimizing, rather than failing, make a small effort |
| to determine the object size without the full benefit of |
| the (costly) computation below. */ |
| gimple *def = SSA_NAME_DEF_STMT (ptr); |
| if (gimple_code (def) == GIMPLE_ASSIGN) |
| { |
| tree_code code = gimple_assign_rhs_code (def); |
| if (code == POINTER_PLUS_EXPR) |
| { |
| tree offset = gimple_assign_rhs2 (def); |
| ptr = gimple_assign_rhs1 (def); |
| |
| if (tree_fits_shwi_p (offset) |
| && compute_builtin_object_size (ptr, object_size_type, |
| psize, pdecl, poff)) |
| { |
| /* Return zero when the offset is out of bounds. */ |
| unsigned HOST_WIDE_INT off = tree_to_shwi (offset); |
| *psize = off < *psize ? *psize - off : 0; |
| *poff = offset; |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr))) |
| { |
| struct object_size_info osi; |
| bitmap_iterator bi; |
| unsigned int i; |
| |
| if (num_ssa_names > object_sizes[object_size_type].length ()) |
| object_sizes[object_size_type].safe_grow (num_ssa_names); |
| if (dump_file) |
| { |
| fprintf (dump_file, "Computing %s %sobject size for ", |
| (object_size_type & 2) ? "minimum" : "maximum", |
| (object_size_type & 1) ? "sub" : ""); |
| print_generic_expr (dump_file, ptr, dump_flags); |
| fprintf (dump_file, ":\n"); |
| } |
| |
| osi.visited = BITMAP_ALLOC (NULL); |
| osi.reexamine = BITMAP_ALLOC (NULL); |
| osi.object_size_type = object_size_type; |
| osi.depths = NULL; |
| osi.stack = NULL; |
| osi.tos = NULL; |
| |
| /* First pass: walk UD chains, compute object sizes that |
| can be computed. osi.reexamine bitmap at the end will |
| contain what variables were found in dependency cycles |
| and therefore need to be reexamined. */ |
| osi.pass = 0; |
| osi.changed = false; |
| collect_object_sizes_for (&osi, ptr); |
| |
| /* Second pass: keep recomputing object sizes of variables |
| that need reexamination, until no object sizes are |
| increased or all object sizes are computed. */ |
| if (! bitmap_empty_p (osi.reexamine)) |
| { |
| bitmap reexamine = BITMAP_ALLOC (NULL); |
| |
| /* If looking for minimum instead of maximum object size, |
| detect cases where a pointer is increased in a loop. |
| Although even without this detection pass 2 would eventually |
| terminate, it could take a long time. If a pointer is |
| increasing this way, we need to assume 0 object size. |
| E.g. p = &buf[0]; while (cond) p = p + 4; */ |
| if (object_size_type & 2) |
| { |
| osi.depths = XCNEWVEC (unsigned int, num_ssa_names); |
| osi.stack = XNEWVEC (unsigned int, num_ssa_names); |
| osi.tos = osi.stack; |
| osi.pass = 1; |
| /* collect_object_sizes_for is changing |
| osi.reexamine bitmap, so iterate over a copy. */ |
| bitmap_copy (reexamine, osi.reexamine); |
| EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) |
| if (bitmap_bit_p (osi.reexamine, i)) |
| check_for_plus_in_loops (&osi, ssa_name (i)); |
| |
| free (osi.depths); |
| osi.depths = NULL; |
| free (osi.stack); |
| osi.stack = NULL; |
| osi.tos = NULL; |
| } |
| |
| do |
| { |
| osi.pass = 2; |
| osi.changed = false; |
| /* collect_object_sizes_for is changing |
| osi.reexamine bitmap, so iterate over a copy. */ |
| bitmap_copy (reexamine, osi.reexamine); |
| EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) |
| if (bitmap_bit_p (osi.reexamine, i)) |
| { |
| collect_object_sizes_for (&osi, ssa_name (i)); |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Reexamining "); |
| print_generic_expr (dump_file, ssa_name (i), |
| dump_flags); |
| fprintf (dump_file, "\n"); |
| } |
| } |
| } |
| while (osi.changed); |
| |
| BITMAP_FREE (reexamine); |
| } |
| EXECUTE_IF_SET_IN_BITMAP (osi.reexamine, 0, i, bi) |
| bitmap_set_bit (computed[object_size_type], i); |
| |
| /* Debugging dumps. */ |
| if (dump_file) |
| { |
| EXECUTE_IF_SET_IN_BITMAP (osi.visited, 0, i, bi) |
| if (object_sizes[object_size_type][i] |
| != unknown[object_size_type]) |
| { |
| print_generic_expr (dump_file, ssa_name (i), |
| dump_flags); |
| fprintf (dump_file, |
| ": %s %sobject size " |
| HOST_WIDE_INT_PRINT_UNSIGNED "\n", |
| (object_size_type & 2) ? "minimum" : "maximum", |
| (object_size_type & 1) ? "sub" : "", |
| object_sizes[object_size_type][i]); |
| } |
| } |
| |
| BITMAP_FREE (osi.reexamine); |
| BITMAP_FREE (osi.visited); |
| } |
| |
| *psize = object_sizes[object_size_type][SSA_NAME_VERSION (ptr)]; |
| return *psize != unknown[object_size_type]; |
| } |
| |
| /* Compute object_sizes for PTR, defined to VALUE, which is not an SSA_NAME. */ |
| |
| static void |
| expr_object_size (struct object_size_info *osi, tree ptr, tree value) |
| { |
| int object_size_type = osi->object_size_type; |
| unsigned int varno = SSA_NAME_VERSION (ptr); |
| unsigned HOST_WIDE_INT bytes; |
| |
| gcc_assert (object_sizes[object_size_type][varno] |
| != unknown[object_size_type]); |
| gcc_assert (osi->pass == 0); |
| |
| if (TREE_CODE (value) == WITH_SIZE_EXPR) |
| value = TREE_OPERAND (value, 0); |
| |
| /* Pointer variables should have been handled by merge_object_sizes. */ |
| gcc_assert (TREE_CODE (value) != SSA_NAME |
| || !POINTER_TYPE_P (TREE_TYPE (value))); |
| |
| if (TREE_CODE (value) == ADDR_EXPR) |
| addr_object_size (osi, value, object_size_type, &bytes); |
| else |
| bytes = unknown[object_size_type]; |
| |
| if ((object_size_type & 2) == 0) |
| { |
| if (object_sizes[object_size_type][varno] < bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| else |
| { |
| if (object_sizes[object_size_type][varno] > bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| } |
| |
| |
| /* Compute object_sizes for PTR, defined to the result of a call. */ |
| |
| static void |
| call_object_size (struct object_size_info *osi, tree ptr, gcall *call) |
| { |
| int object_size_type = osi->object_size_type; |
| unsigned int varno = SSA_NAME_VERSION (ptr); |
| unsigned HOST_WIDE_INT bytes; |
| |
| gcc_assert (is_gimple_call (call)); |
| |
| gcc_assert (object_sizes[object_size_type][varno] |
| != unknown[object_size_type]); |
| gcc_assert (osi->pass == 0); |
| |
| bytes = alloc_object_size (call, object_size_type); |
| |
| if ((object_size_type & 2) == 0) |
| { |
| if (object_sizes[object_size_type][varno] < bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| else |
| { |
| if (object_sizes[object_size_type][varno] > bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| } |
| |
| |
| /* Compute object_sizes for PTR, defined to an unknown value. */ |
| |
| static void |
| unknown_object_size (struct object_size_info *osi, tree ptr) |
| { |
| int object_size_type = osi->object_size_type; |
| unsigned int varno = SSA_NAME_VERSION (ptr); |
| unsigned HOST_WIDE_INT bytes; |
| |
| gcc_assert (object_sizes[object_size_type][varno] |
| != unknown[object_size_type]); |
| gcc_assert (osi->pass == 0); |
| |
| bytes = unknown[object_size_type]; |
| |
| if ((object_size_type & 2) == 0) |
| { |
| if (object_sizes[object_size_type][varno] < bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| else |
| { |
| if (object_sizes[object_size_type][varno] > bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| } |
| |
| |
| /* Merge object sizes of ORIG + OFFSET into DEST. Return true if |
| the object size might need reexamination later. */ |
| |
| static bool |
| merge_object_sizes (struct object_size_info *osi, tree dest, tree orig, |
| unsigned HOST_WIDE_INT offset) |
| { |
| int object_size_type = osi->object_size_type; |
| unsigned int varno = SSA_NAME_VERSION (dest); |
| unsigned HOST_WIDE_INT orig_bytes; |
| |
| if (object_sizes[object_size_type][varno] == unknown[object_size_type]) |
| return false; |
| if (offset >= offset_limit) |
| { |
| object_sizes[object_size_type][varno] = unknown[object_size_type]; |
| return false; |
| } |
| |
| if (osi->pass == 0) |
| collect_object_sizes_for (osi, orig); |
| |
| orig_bytes = object_sizes[object_size_type][SSA_NAME_VERSION (orig)]; |
| if (orig_bytes != unknown[object_size_type]) |
| orig_bytes = (offset > orig_bytes) |
| ? HOST_WIDE_INT_0U : orig_bytes - offset; |
| |
| if ((object_size_type & 2) == 0) |
| { |
| if (object_sizes[object_size_type][varno] < orig_bytes) |
| { |
| object_sizes[object_size_type][varno] = orig_bytes; |
| osi->changed = true; |
| } |
| } |
| else |
| { |
| if (object_sizes[object_size_type][varno] > orig_bytes) |
| { |
| object_sizes[object_size_type][varno] = orig_bytes; |
| osi->changed = true; |
| } |
| } |
| return bitmap_bit_p (osi->reexamine, SSA_NAME_VERSION (orig)); |
| } |
| |
| |
| /* Compute object_sizes for VAR, defined to the result of an assignment |
| with operator POINTER_PLUS_EXPR. Return true if the object size might |
| need reexamination later. */ |
| |
| static bool |
| plus_stmt_object_size (struct object_size_info *osi, tree var, gimple *stmt) |
| { |
| int object_size_type = osi->object_size_type; |
| unsigned int varno = SSA_NAME_VERSION (var); |
| unsigned HOST_WIDE_INT bytes; |
| tree op0, op1; |
| |
| if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) |
| { |
| op0 = gimple_assign_rhs1 (stmt); |
| op1 = gimple_assign_rhs2 (stmt); |
| } |
| else if (gimple_assign_rhs_code (stmt) == ADDR_EXPR) |
| { |
| tree rhs = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0); |
| gcc_assert (TREE_CODE (rhs) == MEM_REF); |
| op0 = TREE_OPERAND (rhs, 0); |
| op1 = TREE_OPERAND (rhs, 1); |
| } |
| else |
| gcc_unreachable (); |
| |
| if (object_sizes[object_size_type][varno] == unknown[object_size_type]) |
| return false; |
| |
| /* Handle PTR + OFFSET here. */ |
| if (TREE_CODE (op1) == INTEGER_CST |
| && (TREE_CODE (op0) == SSA_NAME |
| || TREE_CODE (op0) == ADDR_EXPR)) |
| { |
| if (! tree_fits_uhwi_p (op1)) |
| bytes = unknown[object_size_type]; |
| else if (TREE_CODE (op0) == SSA_NAME) |
| return merge_object_sizes (osi, var, op0, tree_to_uhwi (op1)); |
| else |
| { |
| unsigned HOST_WIDE_INT off = tree_to_uhwi (op1); |
| |
| /* op0 will be ADDR_EXPR here. */ |
| addr_object_size (osi, op0, object_size_type, &bytes); |
| if (bytes == unknown[object_size_type]) |
| ; |
| else if (off > offset_limit) |
| bytes = unknown[object_size_type]; |
| else if (off > bytes) |
| bytes = 0; |
| else |
| bytes -= off; |
| } |
| } |
| else |
| bytes = unknown[object_size_type]; |
| |
| if ((object_size_type & 2) == 0) |
| { |
| if (object_sizes[object_size_type][varno] < bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| else |
| { |
| if (object_sizes[object_size_type][varno] > bytes) |
| object_sizes[object_size_type][varno] = bytes; |
| } |
| return false; |
| } |
| |
| |
| /* Compute object_sizes for VAR, defined at STMT, which is |
| a COND_EXPR. Return true if the object size might need reexamination |
| later. */ |
| |
| static bool |
| cond_expr_object_size (struct object_size_info *osi, tree var, gimple *stmt) |
| { |
| tree then_, else_; |
| int object_size_type = osi->object_size_type; |
| unsigned int varno = SSA_NAME_VERSION (var); |
| bool reexamine = false; |
| |
| gcc_assert (gimple_assign_rhs_code (stmt) == COND_EXPR); |
| |
| if (object_sizes[object_size_type][varno] == unknown[object_size_type]) |
| return false; |
| |
| then_ = gimple_assign_rhs2 (stmt); |
| else_ = gimple_assign_rhs3 (stmt); |
| |
| if (TREE_CODE (then_) == SSA_NAME) |
| reexamine |= merge_object_sizes (osi, var, then_, 0); |
| else |
| expr_object_size (osi, var, then_); |
| |
| if (object_sizes[object_size_type][varno] == unknown[object_size_type]) |
| return reexamine; |
| |
| if (TREE_CODE (else_) == SSA_NAME) |
| reexamine |= merge_object_sizes (osi, var, else_, 0); |
| else |
| expr_object_size (osi, var, else_); |
| |
| return reexamine; |
| } |
| |
| /* Compute object sizes for VAR. |
| For ADDR_EXPR an object size is the number of remaining bytes |
| to the end of the object (where what is considered an object depends on |
| OSI->object_size_type). |
| For allocation GIMPLE_CALL like malloc or calloc object size is the size |
| of the allocation. |
| For POINTER_PLUS_EXPR where second operand is a constant integer, |
| object size is object size of the first operand minus the constant. |
| If the constant is bigger than the number of remaining bytes until the |
| end of the object, object size is 0, but if it is instead a pointer |
| subtraction, object size is unknown[object_size_type]. |
| To differentiate addition from subtraction, ADDR_EXPR returns |
| unknown[object_size_type] for all objects bigger than half of the address |
| space, and constants less than half of the address space are considered |
| addition, while bigger constants subtraction. |
| For a memcpy like GIMPLE_CALL that always returns one of its arguments, the |
| object size is object size of that argument. |
| Otherwise, object size is the maximum of object sizes of variables |
| that it might be set to. */ |
| |
| static void |
| collect_object_sizes_for (struct object_size_info *osi, tree var) |
| { |
| int object_size_type = osi->object_size_type; |
| unsigned int varno = SSA_NAME_VERSION (var); |
| gimple *stmt; |
| bool reexamine; |
| |
| if (bitmap_bit_p (computed[object_size_type], varno)) |
| return; |
| |
| if (osi->pass == 0) |
| { |
| if (bitmap_set_bit (osi->visited, varno)) |
| { |
| object_sizes[object_size_type][varno] |
| = (object_size_type & 2) ? -1 : 0; |
| } |
| else |
| { |
| /* Found a dependency loop. Mark the variable for later |
| re-examination. */ |
| bitmap_set_bit (osi->reexamine, varno); |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Found a dependency loop at "); |
| print_generic_expr (dump_file, var, dump_flags); |
| fprintf (dump_file, "\n"); |
| } |
| return; |
| } |
| } |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Visiting use-def links for "); |
| print_generic_expr (dump_file, var, dump_flags); |
| fprintf (dump_file, "\n"); |
| } |
| |
| stmt = SSA_NAME_DEF_STMT (var); |
| reexamine = false; |
| |
| switch (gimple_code (stmt)) |
| { |
| case GIMPLE_ASSIGN: |
| { |
| tree rhs = gimple_assign_rhs1 (stmt); |
| if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR |
| || (gimple_assign_rhs_code (stmt) == ADDR_EXPR |
| && TREE_CODE (TREE_OPERAND (rhs, 0)) == MEM_REF)) |
| reexamine = plus_stmt_object_size (osi, var, stmt); |
| else if (gimple_assign_rhs_code (stmt) == COND_EXPR) |
| reexamine = cond_expr_object_size (osi, var, stmt); |
| else if (gimple_assign_single_p (stmt) |
| || gimple_assign_unary_nop_p (stmt)) |
| { |
| if (TREE_CODE (rhs) == SSA_NAME |
| && POINTER_TYPE_P (TREE_TYPE (rhs))) |
| reexamine = merge_object_sizes (osi, var, rhs, 0); |
| else |
| expr_object_size (osi, var, rhs); |
| } |
| else |
| unknown_object_size (osi, var); |
| break; |
| } |
| |
| case GIMPLE_CALL: |
| { |
| gcall *call_stmt = as_a <gcall *> (stmt); |
| tree arg = pass_through_call (call_stmt); |
| if (arg) |
| { |
| if (TREE_CODE (arg) == SSA_NAME |
| && POINTER_TYPE_P (TREE_TYPE (arg))) |
| reexamine = merge_object_sizes (osi, var, arg, 0); |
| else |
| expr_object_size (osi, var, arg); |
| } |
| else |
| call_object_size (osi, var, call_stmt); |
| break; |
| } |
| |
| case GIMPLE_ASM: |
| /* Pointers defined by __asm__ statements can point anywhere. */ |
| object_sizes[object_size_type][varno] = unknown[object_size_type]; |
| break; |
| |
| case GIMPLE_NOP: |
| if (SSA_NAME_VAR (var) |
| && TREE_CODE (SSA_NAME_VAR (var)) == PARM_DECL) |
| expr_object_size (osi, var, SSA_NAME_VAR (var)); |
| else |
| /* Uninitialized SSA names point nowhere. */ |
| object_sizes[object_size_type][varno] = unknown[object_size_type]; |
| break; |
| |
| case GIMPLE_PHI: |
| { |
| unsigned i; |
| |
| for (i = 0; i < gimple_phi_num_args (stmt); i++) |
| { |
| tree rhs = gimple_phi_arg (stmt, i)->def; |
| |
| if (object_sizes[object_size_type][varno] |
| == unknown[object_size_type]) |
| break; |
| |
| if (TREE_CODE (rhs) == SSA_NAME) |
| reexamine |= merge_object_sizes (osi, var, rhs, 0); |
| else if (osi->pass == 0) |
| expr_object_size (osi, var, rhs); |
| } |
| break; |
| } |
| |
| default: |
| gcc_unreachable (); |
| } |
| |
| if (! reexamine |
| || object_sizes[object_size_type][varno] == unknown[object_size_type]) |
| { |
| bitmap_set_bit (computed[object_size_type], varno); |
| bitmap_clear_bit (osi->reexamine, varno); |
| } |
| else |
| { |
| bitmap_set_bit (osi->reexamine, varno); |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Need to reexamine "); |
| print_generic_expr (dump_file, var, dump_flags); |
| fprintf (dump_file, "\n"); |
| } |
| } |
| } |
| |
| |
| /* Helper function for check_for_plus_in_loops. Called recursively |
| to detect loops. */ |
| |
| static void |
| check_for_plus_in_loops_1 (struct object_size_info *osi, tree var, |
| unsigned int depth) |
| { |
| gimple *stmt = SSA_NAME_DEF_STMT (var); |
| unsigned int varno = SSA_NAME_VERSION (var); |
| |
| if (osi->depths[varno]) |
| { |
| if (osi->depths[varno] != depth) |
| { |
| unsigned int *sp; |
| |
| /* Found a loop involving pointer addition. */ |
| for (sp = osi->tos; sp > osi->stack; ) |
| { |
| --sp; |
| bitmap_clear_bit (osi->reexamine, *sp); |
| bitmap_set_bit (computed[osi->object_size_type], *sp); |
| object_sizes[osi->object_size_type][*sp] = 0; |
| if (*sp == varno) |
| break; |
| } |
| } |
| return; |
| } |
| else if (! bitmap_bit_p (osi->reexamine, varno)) |
| return; |
| |
| osi->depths[varno] = depth; |
| *osi->tos++ = varno; |
| |
| switch (gimple_code (stmt)) |
| { |
| |
| case GIMPLE_ASSIGN: |
| { |
| if ((gimple_assign_single_p (stmt) |
| || gimple_assign_unary_nop_p (stmt)) |
| && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME) |
| { |
| tree rhs = gimple_assign_rhs1 (stmt); |
| |
| check_for_plus_in_loops_1 (osi, rhs, depth); |
| } |
| else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) |
| { |
| tree basevar = gimple_assign_rhs1 (stmt); |
| tree cst = gimple_assign_rhs2 (stmt); |
| |
| gcc_assert (TREE_CODE (cst) == INTEGER_CST); |
| |
| check_for_plus_in_loops_1 (osi, basevar, |
| depth + !integer_zerop (cst)); |
| } |
| else |
| gcc_unreachable (); |
| break; |
| } |
| |
| case GIMPLE_CALL: |
| { |
| gcall *call_stmt = as_a <gcall *> (stmt); |
| tree arg = pass_through_call (call_stmt); |
| if (arg) |
| { |
| if (TREE_CODE (arg) == SSA_NAME) |
| check_for_plus_in_loops_1 (osi, arg, depth); |
| else |
| gcc_unreachable (); |
| } |
| break; |
| } |
| |
| case GIMPLE_PHI: |
| { |
| unsigned i; |
| |
| for (i = 0; i < gimple_phi_num_args (stmt); i++) |
| { |
| tree rhs = gimple_phi_arg (stmt, i)->def; |
| |
| if (TREE_CODE (rhs) == SSA_NAME) |
| check_for_plus_in_loops_1 (osi, rhs, depth); |
| } |
| break; |
| } |
| |
| default: |
| gcc_unreachable (); |
| } |
| |
| osi->depths[varno] = 0; |
| osi->tos--; |
| } |
| |
| |
| /* Check if some pointer we are computing object size of is being increased |
| within a loop. If yes, assume all the SSA variables participating in |
| that loop have minimum object sizes 0. */ |
| |
| static void |
| check_for_plus_in_loops (struct object_size_info *osi, tree var) |
| { |
| gimple *stmt = SSA_NAME_DEF_STMT (var); |
| |
| /* NOTE: In the pre-tuples code, we handled a CALL_EXPR here, |
| and looked for a POINTER_PLUS_EXPR in the pass-through |
| argument, if any. In GIMPLE, however, such an expression |
| is not a valid call operand. */ |
| |
| if (is_gimple_assign (stmt) |
| && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) |
| { |
| tree basevar = gimple_assign_rhs1 (stmt); |
| tree cst = gimple_assign_rhs2 (stmt); |
| |
| gcc_assert (TREE_CODE (cst) == INTEGER_CST); |
| |
| if (integer_zerop (cst)) |
| return; |
| |
| osi->depths[SSA_NAME_VERSION (basevar)] = 1; |
| *osi->tos++ = SSA_NAME_VERSION (basevar); |
| check_for_plus_in_loops_1 (osi, var, 2); |
| osi->depths[SSA_NAME_VERSION (basevar)] = 0; |
| osi->tos--; |
| } |
| } |
| |
| |
| /* Initialize data structures for the object size computation. */ |
| |
| void |
| init_object_sizes (void) |
| { |
| int object_size_type; |
| |
| if (computed[0]) |
| return; |
| |
| for (object_size_type = 0; object_size_type <= 3; object_size_type++) |
| { |
| object_sizes[object_size_type].safe_grow (num_ssa_names); |
| computed[object_size_type] = BITMAP_ALLOC (NULL); |
| } |
| |
| init_offset_limit (); |
| } |
| |
| |
| /* Destroy data structures after the object size computation. */ |
| |
| void |
| fini_object_sizes (void) |
| { |
| int object_size_type; |
| |
| for (object_size_type = 0; object_size_type <= 3; object_size_type++) |
| { |
| object_sizes[object_size_type].release (); |
| BITMAP_FREE (computed[object_size_type]); |
| } |
| } |
| |
| |
| /* Simple pass to optimize all __builtin_object_size () builtins. */ |
| |
| namespace { |
| |
| const pass_data pass_data_object_sizes = |
| { |
| GIMPLE_PASS, /* type */ |
| "objsz", /* name */ |
| OPTGROUP_NONE, /* optinfo_flags */ |
| TV_NONE, /* tv_id */ |
| ( PROP_cfg | PROP_ssa ), /* properties_required */ |
| 0, /* properties_provided */ |
| 0, /* properties_destroyed */ |
| 0, /* todo_flags_start */ |
| 0, /* todo_flags_finish */ |
| }; |
| |
| class pass_object_sizes : public gimple_opt_pass |
| { |
| public: |
| pass_object_sizes (gcc::context *ctxt) |
| : gimple_opt_pass (pass_data_object_sizes, ctxt), insert_min_max_p (false) |
| {} |
| |
| /* opt_pass methods: */ |
| opt_pass * clone () { return new pass_object_sizes (m_ctxt); } |
| void set_pass_param (unsigned int n, bool param) |
| { |
| gcc_assert (n == 0); |
| insert_min_max_p = param; |
| } |
| virtual unsigned int execute (function *); |
| |
| private: |
| /* Determines whether the pass instance creates MIN/MAX_EXPRs. */ |
| bool insert_min_max_p; |
| }; // class pass_object_sizes |
| |
| /* Dummy valueize function. */ |
| |
| static tree |
| do_valueize (tree t) |
| { |
| return t; |
| } |
| |
| unsigned int |
| pass_object_sizes::execute (function *fun) |
| { |
| basic_block bb; |
| FOR_EACH_BB_FN (bb, fun) |
| { |
| gimple_stmt_iterator i; |
| for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) |
| { |
| tree result; |
| gimple *call = gsi_stmt (i); |
| if (!gimple_call_builtin_p (call, BUILT_IN_OBJECT_SIZE)) |
| continue; |
| |
| init_object_sizes (); |
| |
| /* If insert_min_max_p, only attempt to fold |
| __builtin_object_size (x, 1) and __builtin_object_size (x, 3), |
| and rather than folding the builtin to the constant if any, |
| create a MIN_EXPR or MAX_EXPR of the __builtin_object_size |
| call result and the computed constant. */ |
| if (insert_min_max_p) |
| { |
| tree ost = gimple_call_arg (call, 1); |
| if (tree_fits_uhwi_p (ost)) |
| { |
| unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost); |
| tree ptr = gimple_call_arg (call, 0); |
| tree lhs = gimple_call_lhs (call); |
| if ((object_size_type == 1 || object_size_type == 3) |
| && (TREE_CODE (ptr) == ADDR_EXPR |
| || TREE_CODE (ptr) == SSA_NAME) |
| && lhs) |
| { |
| tree type = TREE_TYPE (lhs); |
| unsigned HOST_WIDE_INT bytes; |
| if (compute_builtin_object_size (ptr, object_size_type, |
| &bytes) |
| && wi::fits_to_tree_p (bytes, type)) |
| { |
| tree tem = make_ssa_name (type); |
| gimple_call_set_lhs (call, tem); |
| enum tree_code code |
| = object_size_type == 1 ? MIN_EXPR : MAX_EXPR; |
| tree cst = build_int_cstu (type, bytes); |
| gimple *g |
| = gimple_build_assign (lhs, code, tem, cst); |
| gsi_insert_after (&i, g, GSI_NEW_STMT); |
| update_stmt (call); |
| } |
| } |
| } |
| continue; |
| } |
| |
| tree lhs = gimple_call_lhs (call); |
| if (!lhs) |
| continue; |
| |
| result = gimple_fold_stmt_to_constant (call, do_valueize); |
| if (!result) |
| { |
| tree ost = gimple_call_arg (call, 1); |
| |
| if (tree_fits_uhwi_p (ost)) |
| { |
| unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost); |
| |
| if (object_size_type < 2) |
| result = fold_convert (size_type_node, |
| integer_minus_one_node); |
| else if (object_size_type < 4) |
| result = build_zero_cst (size_type_node); |
| } |
| |
| if (!result) |
| continue; |
| } |
| |
| gcc_assert (TREE_CODE (result) == INTEGER_CST); |
| |
| if (dump_file && (dump_flags & TDF_DETAILS)) |
| { |
| fprintf (dump_file, "Simplified\n "); |
| print_gimple_stmt (dump_file, call, 0, dump_flags); |
| fprintf (dump_file, " to "); |
| print_generic_expr (dump_file, result); |
| fprintf (dump_file, "\n"); |
| } |
| |
| /* Propagate into all uses and fold those stmts. */ |
| if (!SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
| replace_uses_by (lhs, result); |
| else |
| replace_call_with_value (&i, result); |
| } |
| } |
| |
| fini_object_sizes (); |
| return 0; |
| } |
| |
| } // anon namespace |
| |
| gimple_opt_pass * |
| make_pass_object_sizes (gcc::context *ctxt) |
| { |
| return new pass_object_sizes (ctxt); |
| } |