Hello!
Attached patch uses ssememalign attribute to reject insn combinations
where memory operands would be misaligned.
2015-11-12 Uros Bizjak <ubiz...@gmail.com>
* config/i386/i386.c (ix86_legitimate_combined_insn): Reject
combined insn if the alignment of vector mode memory operand
is less than ssememalign.
testsuite/ChangeLog:
2015-11-12 Uros Bizjak <ubiz...@gmail.com>
* gcc.target/i386/sse-1.c (swizzle): Assume that a is
aligned to 64 bits.
Patch was bootstrapped and regression tested on x86_64-linux-gnu
{,-m32}, committed to mainline SVN.
Uros.
Index: config/i386/i386.c
===================================================================
--- config/i386/i386.c (revision 230213)
+++ config/i386/i386.c (working copy)
@@ -7236,11 +7236,12 @@ ix86_legitimate_combined_insn (rtx_insn *insn)
/* For pre-AVX disallow unaligned loads/stores where the
instructions don't support it. */
if (!TARGET_AVX
- && VECTOR_MODE_P (GET_MODE (op))
- && misaligned_operand (op, GET_MODE (op)))
+ && VECTOR_MODE_P (mode)
+ && misaligned_operand (op, mode))
{
- int min_align = get_attr_ssememalign (insn);
- if (min_align == 0)
+ unsigned int min_align = get_attr_ssememalign (insn);
+ if (min_align == 0
+ || MEM_ALIGN (op) < min_align)
return false;
}
Index: testsuite/gcc.target/i386/sse-1.c
===================================================================
--- testsuite/gcc.target/i386/sse-1.c (revision 230213)
+++ testsuite/gcc.target/i386/sse-1.c (working copy)
@@ -14,8 +14,10 @@ typedef union
void
swizzle (const void *a, vector4_t * b, vector4_t * c)
{
- b->v = _mm_loadl_pi (b->v, (__m64 *) a);
- c->v = _mm_loadl_pi (c->v, ((__m64 *) a) + 1);
+ __m64 *t = __builtin_assume_aligned (a, 64);
+
+ b->v = _mm_loadl_pi (b->v, t);
+ c->v = _mm_loadl_pi (c->v, t + 1);
}
/* While one legal rendering of each statement would be movaps;movlps;movaps,
