From 625ed1721782f6ec522c764e0119d1ad2214f624 Mon Sep 17 00:00:00 2001 From: Michael Matz Date: Thu, 21 Jun 2012 12:18:23 +0000 Subject: [PATCH] re PR middle-end/53688 (191.fma3d in SPEC CPU 2000 miscompiled) PR middle-end/53688 * builtins.c (get_memory_rtx): Always build an all-aliasing MEM_REF with correct size. testsuite/ * gcc.c-torture/execute/pr53688.c: New test. From-SVN: r188852 --- gcc/ChangeLog | 6 ++ gcc/builtins.c | 135 +++++--------------------- gcc/testsuite/ChangeLog | 7 +- gcc/testsuite/gcc.c-torture/execute/pr53688.c | 32 ++++++ 4 files changed, 70 insertions(+), 110 deletions(-) create mode 100644 gcc/testsuite/gcc.c-torture/execute/pr53688.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 42bddf9..ebe422d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2012-06-21 Michael Matz + + PR middle-end/53688 + * builtins.c (get_memory_rtx): Always build an all-aliasing MEM_REF + with correct size. + 2012-06-21 Richard Guenther * tree-inline.c (estimate_num_insns): Estimate call cost for diff --git a/gcc/builtins.c b/gcc/builtins.c index b9dd399..c12eb29 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -1252,7 +1252,6 @@ get_memory_rtx (tree exp, tree len) { tree orig_exp = exp; rtx addr, mem; - HOST_WIDE_INT off; /* When EXP is not resolved SAVE_EXPR, MEM_ATTRS can be still derived from its expression, for expr->a.b only .a.b is recorded. */ @@ -1263,120 +1262,38 @@ get_memory_rtx (tree exp, tree len) mem = gen_rtx_MEM (BLKmode, memory_address (BLKmode, addr)); /* Get an expression we can use to find the attributes to assign to MEM. - If it is an ADDR_EXPR, use the operand. Otherwise, dereference it if - we can. First remove any nops. */ + First remove any nops. */ while (CONVERT_EXPR_P (exp) && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (exp, 0)))) exp = TREE_OPERAND (exp, 0); - off = 0; - if (TREE_CODE (exp) == POINTER_PLUS_EXPR - && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR - && host_integerp (TREE_OPERAND (exp, 1), 0) - && (off = tree_low_cst (TREE_OPERAND (exp, 1), 0)) > 0) - exp = TREE_OPERAND (TREE_OPERAND (exp, 0), 0); - else if (TREE_CODE (exp) == ADDR_EXPR) - exp = TREE_OPERAND (exp, 0); - else if (POINTER_TYPE_P (TREE_TYPE (exp))) - exp = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (exp)), exp); - else - exp = NULL; - - /* Honor attributes derived from exp, except for the alias set - (as builtin stringops may alias with anything) and the size - (as stringops may access multiple array elements). */ - if (exp) - { + /* Build a MEM_REF representing the whole accessed area as a byte blob, + (as builtin stringops may alias with anything). */ + exp = fold_build2 (MEM_REF, + build_array_type (char_type_node, + build_range_type (sizetype, + size_one_node, len)), + exp, build_int_cst (ptr_type_node, 0)); + + /* If the MEM_REF has no acceptable address, try to get the base object + from the original address we got, and build an all-aliasing + unknown-sized access to that one. */ + if (is_gimple_mem_ref_addr (TREE_OPERAND (exp, 0))) + set_mem_attributes (mem, exp, 0); + else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR + && (exp = get_base_address (TREE_OPERAND (TREE_OPERAND (exp, 0), + 0)))) + { + exp = build_fold_addr_expr (exp); + exp = fold_build2 (MEM_REF, + build_array_type (char_type_node, + build_range_type (sizetype, + size_zero_node, + NULL)), + exp, build_int_cst (ptr_type_node, 0)); set_mem_attributes (mem, exp, 0); - - if (off) - mem = adjust_automodify_address_nv (mem, BLKmode, NULL, off); - - /* Allow the string and memory builtins to overflow from one - field into another, see http://gcc.gnu.org/PR23561. - Thus avoid COMPONENT_REFs in MEM_EXPR unless we know the whole - memory accessed by the string or memory builtin will fit - within the field. */ - if (MEM_EXPR (mem) && TREE_CODE (MEM_EXPR (mem)) == COMPONENT_REF) - { - tree mem_expr = MEM_EXPR (mem); - HOST_WIDE_INT offset = -1, length = -1; - tree inner = exp; - - while (TREE_CODE (inner) == ARRAY_REF - || CONVERT_EXPR_P (inner) - || TREE_CODE (inner) == VIEW_CONVERT_EXPR - || TREE_CODE (inner) == SAVE_EXPR) - inner = TREE_OPERAND (inner, 0); - - gcc_assert (TREE_CODE (inner) == COMPONENT_REF); - - if (MEM_OFFSET_KNOWN_P (mem)) - offset = MEM_OFFSET (mem); - - if (offset >= 0 && len && host_integerp (len, 0)) - length = tree_low_cst (len, 0); - - while (TREE_CODE (inner) == COMPONENT_REF) - { - tree field = TREE_OPERAND (inner, 1); - gcc_assert (TREE_CODE (mem_expr) == COMPONENT_REF); - gcc_assert (field == TREE_OPERAND (mem_expr, 1)); - - /* Bitfields are generally not byte-addressable. */ - gcc_assert (!DECL_BIT_FIELD (field) - || ((tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) - % BITS_PER_UNIT) == 0 - && host_integerp (DECL_SIZE (field), 0) - && (TREE_INT_CST_LOW (DECL_SIZE (field)) - % BITS_PER_UNIT) == 0)); - - /* If we can prove that the memory starting at XEXP (mem, 0) and - ending at XEXP (mem, 0) + LENGTH will fit into this field, we - can keep the COMPONENT_REF in MEM_EXPR. But be careful with - fields without DECL_SIZE_UNIT like flexible array members. */ - if (length >= 0 - && DECL_SIZE_UNIT (field) - && host_integerp (DECL_SIZE_UNIT (field), 0)) - { - HOST_WIDE_INT size - = TREE_INT_CST_LOW (DECL_SIZE_UNIT (field)); - if (offset <= size - && length <= size - && offset + length <= size) - break; - } - - if (offset >= 0 - && host_integerp (DECL_FIELD_OFFSET (field), 0)) - offset += TREE_INT_CST_LOW (DECL_FIELD_OFFSET (field)) - + tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1) - / BITS_PER_UNIT; - else - { - offset = -1; - length = -1; - } - - mem_expr = TREE_OPERAND (mem_expr, 0); - inner = TREE_OPERAND (inner, 0); - } - - if (mem_expr == NULL) - offset = -1; - if (mem_expr != MEM_EXPR (mem)) - { - set_mem_expr (mem, mem_expr); - if (offset >= 0) - set_mem_offset (mem, offset); - else - clear_mem_offset (mem); - } - } - set_mem_alias_set (mem, 0); - clear_mem_size (mem); } - + set_mem_alias_set (mem, 0); return mem; } diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 60b0828..a16c702 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2012-06-21 Michael Matz + + PR middle-end/53688 + * gcc.c-torture/execute/pr53688.c: New test. + 2012-06-20 Richard Guenther PR tree-optimization/30318 @@ -24,7 +29,7 @@ 2012-06-16 Ville Voutilainen - * g++.dg/cpp0x/override4.C: New. + * g++.dg/cpp0x/override4.C: New. 2012-06-14 Jason Merrill diff --git a/gcc/testsuite/gcc.c-torture/execute/pr53688.c b/gcc/testsuite/gcc.c-torture/execute/pr53688.c new file mode 100644 index 0000000..c7ed4d7 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr53688.c @@ -0,0 +1,32 @@ +char headline[256]; +struct hdr { + char part1[9]; + char part2[8]; +} p; + +void __attribute__((noinline,noclone)) +init() +{ + __builtin_memcpy (p.part1, "FOOBARFOO", sizeof (p.part1)); + __builtin_memcpy (p.part2, "SPEC CPU", sizeof (p.part2)); +} + +int main() +{ + char *x; + int c; + init(); + __builtin_memcpy (&headline[0], p.part1, 9); + c = 9; + x = &headline[0]; + x = x + c; + __builtin_memset (x, ' ', 245); + __builtin_memcpy (&headline[10], p.part2, 8); + c = 18; + x = &headline[0]; + x = x + c; + __builtin_memset (x, ' ', 238); + if (headline[10] != 'S') + __builtin_abort (); + return 0; +} -- 2.7.4