On Wed, Aug 10, 2011 at 4:42 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
> On Wed, Aug 10, 2011 at 7:12 AM, Richard Guenther
> <richard.guent...@gmail.com> wrote:
>> On Wed, Aug 10, 2011 at 4:04 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
>>> On Wed, Aug 10, 2011 at 6:46 AM, Richard Guenther
>>> <richard.guent...@gmail.com> wrote:
>>>> On Sat, Mar 29, 2008 at 10:11 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
>>>>> This patch restores proper checking the third argument on blendpd and
>>>>> and blendps. It also adds 2 tests, including pblendw. Tested on
>>>>> Linux/Intel64. OK to install?
>>>>
>>>> The gcc.target/i386/sse4_1-blendps-2.c test randomly fails because
>>>> src3 is used uninitialized.
>>>>
>>>
>>> SRC2 may be uninitialized. But I never saw random failures
>>> since it checks if random value in SRC2 is properly blended.
>>
>> No, src2 is initialized via init_blendps (src1.f, src2.f), src3 is
>> uninitialized.
>> I see random execute fails on Nehalem.
>>
>> I suppose we might optimize the uninitialized memory (it's probably
>> committed to registers) based on the undefined behavior.
>>
>> Please avoid this by initializing src3 properly.
>>
>
> Here is a patch. OK for trunk?
Ok.
Richard.
>
> --
> H.J.
> ----
> diff --git a/gcc/testsuite/gcc.target/i386/sse4_1-blendps-2.c
> b/gcc/testsuite/gcc.target/i386/sse4_1-blendps-2.c
> index b66bbfd..af56e14 100644
> --- a/gcc/testsuite/gcc.target/i386/sse4_1-blendps-2.c
> +++ b/gcc/testsuite/gcc.target/i386/sse4_1-blendps-2.c
> @@ -6,6 +6,7 @@
>
> #include <smmintrin.h>
> #include <string.h>
> +#include <stdlib.h>
>
> #define NUM 20
>
> @@ -52,11 +53,15 @@ sse4_1_test (void)
> {
> __m128 x;
> float f[4];
> + int i[4];
> } src3;
> int i;
>
> init_blendps (src1.f, src2.f);
>
> + for (i = 0; i < 4; i++)
> + src3.i[i] = (int) random ();
> +
> /* Check blendps imm8, m128, xmm */
> for (i = 0; i < NUM; i++)
> {
>
