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expr.c (expand_assignment): Handle misaligned scalar writes to memory through top-level MEM_REFs by calling...

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2012-03-13  Martin Jambor  <mjambor@suse.cz>

	* expr.c (expand_assignment): Handle misaligned scalar writes to
	memory through top-level MEM_REFs by calling store_bit_field.

	* testsuite/gcc.dg/misaligned-expand-2.c: New test.

From-SVN: r185336
This commit is contained in:
Martin Jambor 2012-03-13 15:29:42 +01:00 • committed by Martin Jambor
parent 3985be599e
commit 43332529ed
4 changed files with 66 additions and 7 deletions
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5
gcc/ChangeLog
View file

@ -1,3 +1,8 @@
2012-03-13 Martin Jambor <mjambor@suse.cz>
* expr.c (expand_assignment): Handle misaligned scalar writes to
memory through top-level MEM_REFs by calling store_bit_field.
2012-03-13 Richard Guenther <rguenther@suse.de>
PR middle-end/52134

22
gcc/expr.c
View file

@ -4593,10 +4593,12 @@ expand_assignment (tree to, tree from, bool nontemporal)
if ((TREE_CODE (to) == MEM_REF
|| TREE_CODE (to) == TARGET_MEM_REF)
&& mode != BLKmode
&& !mem_ref_refers_to_non_mem_p (to)
&& ((align = get_object_or_type_alignment (to))
< GET_MODE_ALIGNMENT (mode))
&& ((icode = optab_handler (movmisalign_optab, mode))
!= CODE_FOR_nothing))
&& (((icode = optab_handler (movmisalign_optab, mode))
!= CODE_FOR_nothing)
|| SLOW_UNALIGNED_ACCESS (mode, align)))
{
addr_space_t as
= TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (to, 0))));
@ -4639,11 +4641,17 @@ expand_assignment (tree to, tree from, bool nontemporal)
if (TREE_THIS_VOLATILE (to))
MEM_VOLATILE_P (mem) = 1;
create_fixed_operand (&ops[0], mem);
create_input_operand (&ops[1], reg, mode);
/* The movmisalign<mode> pattern cannot fail, else the assignment would
silently be omitted. */
expand_insn (icode, 2, ops);
if (icode != CODE_FOR_nothing)
{
create_fixed_operand (&ops[0], mem);
create_input_operand (&ops[1], reg, mode);
/* The movmisalign<mode> pattern cannot fail, else the assignment
would silently be omitted. */
expand_insn (icode, 2, ops);
}
else
store_bit_field (mem, GET_MODE_BITSIZE (mode),
0, 0, 0, mode, reg);
return;
}

4
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,7 @@
2012-03-13 Martin Jambor <mjambor@suse.cz>
* gcc.dg/misaligned-expand-2.c: New test.
2012-03-13 Richard Guenther <rguenther@suse.de>
PR middle-end/52134

42
gcc/testsuite/gcc.dg/misaligned-expand-2.c Normal file
View file

@ -0,0 +1,42 @@
/* Test that expand can generate correct stores to misaligned data even on
strict alignment platforms. */
/* { dg-do run } */
/* { dg-options "-O0" } */
extern void abort ();
typedef unsigned int myint __attribute__((aligned(1)));
void
foo (myint *p, unsigned int i)
{
*p = i;
}
#define cst 0xdeadbeef
#define NUM 8
struct blah
{
char c;
myint i[NUM];
};
struct blah g;
#define cst 0xdeadbeef
int
main (int argc, char **argv)
{
int k;
for (k = 0; k < NUM; k++)
{
foo (&g.i[k], cst);
if (g.i[k] != cst)
abort ();
}
return 0;
}