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re PR middle-end/64516 (arm: wrong unaligned load generated)

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2016-06-13  Richard Biener  <rguenther@suse.de>

	PR middle-end/64516
	* fold-const.c (fold_unary_loc): Preserve alignment when
	folding a VIEW_CONVERT_EXPR into a MEM_REF.

	* gcc.dg/align-3.c: New testcase.

From-SVN: r237355
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Richard Biener 2016-06-13 07:34:45 +00:00 • committed by Richard Biener
parent f423253bd7
commit f57f53d3a5
4 changed files with 24 additions and 0 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2016-06-13 Richard Biener <rguenther@suse.de>
PR middle-end/64516
* fold-const.c (fold_unary_loc): Preserve alignment when
folding a VIEW_CONVERT_EXPR into a MEM_REF.
2016-06-13 Martin Liska <mliska@suse.cz>
PR sanitizer/71458

2
gcc/fold-const.c
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@ -7975,6 +7975,8 @@ fold_unary_loc (location_t loc, enum tree_code code, tree type, tree op0)
case VIEW_CONVERT_EXPR:
if (TREE_CODE (op0) == MEM_REF)
{
if (TYPE_ALIGN (TREE_TYPE (op0)) != TYPE_ALIGN (type))
type = build_aligned_type (type, TYPE_ALIGN (TREE_TYPE (op0)));
tem = fold_build2_loc (loc, MEM_REF, type,
TREE_OPERAND (op0, 0), TREE_OPERAND (op0, 1));
REF_REVERSE_STORAGE_ORDER (tem) = REF_REVERSE_STORAGE_ORDER (op0);

5
gcc/testsuite/ChangeLog
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@ -1,3 +1,8 @@
2016-06-13 Richard Biener <rguenther@suse.de>
PR middle-end/64516
* gcc.dg/align-3.c: New testcase.
2016-06-13 Martin Liska <mliska@suse.cz>
* gcc.target/i386/pr71458.c: New test.

11
gcc/testsuite/gcc.dg/align-3.c Normal file
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@ -0,0 +1,11 @@
/* { dg-do compile } */
/* { dg-options "-O2 -fdump-rtl-expand" } */
typedef struct { char a[2]; } __attribute__((__packed__)) TU2;
unsigned short get16_unaligned(const void *p) {
unsigned short v;
*(TU2 *)(void *)(&v) = *(const TU2 *)p;
return v;
}
/* { dg-final { scan-rtl-dump "MEM\[^\n\r\]*A8\\\]" "expand" } } */