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Re: [PATCH, i386, AVX] Fix typo in i386.c/standard_sse_constant_opcode ().


On 23 Mar 12:41, Jakub Jelinek wrote:
> On Wed, Mar 23, 2016 at 02:28:03PM +0300, Kirill Yukhin wrote:
> > Hello,
> > 
> > `vpcmpeqd' insn is only available in AVX2, however
> > [1] added check for AVX instead. Looks like a typo.
> > 
> > Patch in the bottom fixes that.
> > 
> > Bootstrapped, regtest still run.
> > Is it ok for main trunk if pass?
> 
> ??
> I see
> VEX.NDS.128.66.0F.WIG 76 /r	RVM	V/V	AVX	Compare packed doublewords in xmm3/m128 and
> VPCMPEQD xmm1, xmm2, xmm3/m128				xmm2 for equality.
> and
> VEX.NDS.256.66.0F.WIG 76 /r	RVM	V/V	AVX2	Compare packed doublewords in ymm3/m256 and
> VPCMPEQD ymm1, ymm2, ymm3 /m256				ymm2 for equality.
> in the ISA pdfs.
> This code is only executed if standard_sse_constant_p returns 2, which
> is for 16-byte vectors and all ones for TARGET_SSE2, and for
> 32-byte vectors for TARGET_AVX2.
> Thus, IMNSHO the patch is wrong, even for plain -mavx -mno-avx2
> we want to emit vpcmpeqd %xmm?, %xmm?, %xmm?, so that we don't mix
> VEX with non-VEX encoded insns.
You're right. I've updated the patch to check mode size as well.

--
Thanks, K

commit ae82089e3a4244d870737a7022e66e87042da811
Author: Kirill Yukhin <kirill.yukhin@intel.com>
Date:   Wed Mar 23 14:08:07 2016 +0300

    AVX2. Emit vpcmpeqd for const_m1 only if AVX2 is enabled.

diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 1639704..963cc3d 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -10859,7 +10859,7 @@ standard_sse_constant_opcode (rtx_insn *insn, rtx x)
          || get_attr_mode (insn) == MODE_V8DF
          || get_attr_mode (insn) == MODE_V16SF)
        return "vpternlogd\t{$0xFF, %g0, %g0, %g0|%g0, %g0, %g0, 0xFF}";
-      if (TARGET_AVX)
+      if (TARGET_AVX2 || get_attr_mode (insn) == 16)
        return "vpcmpeqd\t%0, %0, %0";
       else
        return "pcmpeqd\t%0, %0";


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