[X86] Use vptestm/vptestnm for comparisons with zero to avoid creating a zero vector.

We can use the same input for both operands to get a free compare with zero.

We already use this trick in a couple places where we explicitly create PTESTM with the same input twice. This generalizes it.

I'm hoping to remove the ISD opcodes and move this to isel patterns like we do for scalar cmp/test.

llvm-svn: 323605

1 files changed, 15 insertions, 20 deletions

diff --git a/llvm/test/CodeGen/X86/compress_expand.ll b/llvm/test/CodeGen/X86/compress_expand.ll
index fb550be6310..57767e23e3d 100644
--- a/llvm/test/CodeGen/X86/compress_expand.ll
+++ b/llvm/test/CodeGen/X86/compress_expand.ll
@@ -256,7 +256,7 @@ define <2 x float> @test13(float* %base, <2 x float> %src0, <2 x i32> %trigger)
 ; SKX:       # %bb.0:
 ; SKX-NEXT:    vpxor %xmm2, %xmm2, %xmm2
 ; SKX-NEXT:    vpblendd {{.*#+}} xmm1 = xmm1[0],xmm2[1],xmm1[2],xmm2[3]
-; SKX-NEXT:    vpcmpeqq %xmm2, %xmm1, %k1
+; SKX-NEXT:    vptestnmq %xmm1, %xmm1, %k1
 ; SKX-NEXT:    vexpandps (%rdi), %xmm0 {%k1}
 ; SKX-NEXT:    retq
 ;
@@ -265,7 +265,7 @@ define <2 x float> @test13(float* %base, <2 x float> %src0, <2 x i32> %trigger)
 ; KNL-NEXT:    # kill: def %xmm0 killed %xmm0 def %zmm0
 ; KNL-NEXT:    vpxor %xmm2, %xmm2, %xmm2
 ; KNL-NEXT:    vpblendd {{.*#+}} xmm1 = xmm1[0],xmm2[1],xmm1[2],xmm2[3]
-; KNL-NEXT:    vpcmpeqq %zmm2, %zmm1, %k0
+; KNL-NEXT:    vptestnmq %zmm1, %zmm1, %k0
 ; KNL-NEXT:    kshiftlw $14, %k0, %k0
 ; KNL-NEXT:    kshiftrw $14, %k0, %k1
 ; KNL-NEXT:    vexpandps (%rdi), %zmm0 {%k1}
@@ -281,7 +281,7 @@ define void @test14(float* %base, <2 x float> %V, <2 x i32> %trigger) {
 ; SKX:       # %bb.0:
 ; SKX-NEXT:    vpxor %xmm2, %xmm2, %xmm2
 ; SKX-NEXT:    vpblendd {{.*#+}} xmm1 = xmm1[0],xmm2[1],xmm1[2],xmm2[3]
-; SKX-NEXT:    vpcmpeqq %xmm2, %xmm1, %k1
+; SKX-NEXT:    vptestnmq %xmm1, %xmm1, %k1
 ; SKX-NEXT:    vcompressps %xmm0, (%rdi) {%k1}
 ; SKX-NEXT:    retq
 ;
@@ -290,7 +290,7 @@ define void @test14(float* %base, <2 x float> %V, <2 x i32> %trigger) {
 ; KNL-NEXT:    # kill: def %xmm0 killed %xmm0 def %zmm0
 ; KNL-NEXT:    vpxor %xmm2, %xmm2, %xmm2
 ; KNL-NEXT:    vpblendd {{.*#+}} xmm1 = xmm1[0],xmm2[1],xmm1[2],xmm2[3]
-; KNL-NEXT:    vpcmpeqq %zmm2, %zmm1, %k0
+; KNL-NEXT:    vptestnmq %zmm1, %zmm1, %k0
 ; KNL-NEXT:    kshiftlw $14, %k0, %k0
 ; KNL-NEXT:    kshiftrw $14, %k0, %k1
 ; KNL-NEXT:    vcompressps %zmm0, (%rdi) {%k1}
@@ -303,9 +303,8 @@ define void @test14(float* %base, <2 x float> %V, <2 x i32> %trigger) {
 define <32 x float> @test15(float* %base, <32 x float> %src0, <32 x i32> %trigger) {
 ; ALL-LABEL: test15:
 ; ALL:       # %bb.0:
-; ALL-NEXT:    vpxor %xmm4, %xmm4, %xmm4
-; ALL-NEXT:    vpcmpeqd %zmm4, %zmm3, %k1
-; ALL-NEXT:    vpcmpeqd %zmm4, %zmm2, %k2
+; ALL-NEXT:    vptestnmd %zmm3, %zmm3, %k1
+; ALL-NEXT:    vptestnmd %zmm2, %zmm2, %k2
 ; ALL-NEXT:    kmovw %k2, %eax
 ; ALL-NEXT:    popcntl %eax, %eax
 ; ALL-NEXT:    vexpandps (%rdi,%rax,4), %zmm1 {%k1}
@@ -320,9 +319,8 @@ define <16 x double> @test16(double* %base, <16 x double> %src0, <16 x i32> %tri
 ; SKX-LABEL: test16:
 ; SKX:       # %bb.0:
 ; SKX-NEXT:    vextracti64x4 $1, %zmm2, %ymm3
-; SKX-NEXT:    vpxor %xmm4, %xmm4, %xmm4
-; SKX-NEXT:    vpcmpeqd %ymm4, %ymm3, %k1
-; SKX-NEXT:    vpcmpeqd %ymm4, %ymm2, %k2
+; SKX-NEXT:    vptestnmd %ymm3, %ymm3, %k1
+; SKX-NEXT:    vptestnmd %ymm2, %ymm2, %k2
 ; SKX-NEXT:    kmovb %k2, %eax
 ; SKX-NEXT:    popcntl %eax, %eax
 ; SKX-NEXT:    vexpandpd (%rdi,%rax,8), %zmm1 {%k1}
@@ -331,10 +329,9 @@ define <16 x double> @test16(double* %base, <16 x double> %src0, <16 x i32> %tri
 ;
 ; KNL-LABEL: test16:
 ; KNL:       # %bb.0:
-; KNL-NEXT:    vpxor %xmm3, %xmm3, %xmm3
-; KNL-NEXT:    vextracti64x4 $1, %zmm2, %ymm4
-; KNL-NEXT:    vpcmpeqd %zmm3, %zmm4, %k1
-; KNL-NEXT:    vpcmpeqd %zmm3, %zmm2, %k2
+; KNL-NEXT:    vextracti64x4 $1, %zmm2, %ymm3
+; KNL-NEXT:    vptestnmd %zmm3, %zmm3, %k1
+; KNL-NEXT:    vptestnmd %zmm2, %zmm2, %k2
 ; KNL-NEXT:    vexpandpd (%rdi), %zmm0 {%k2}
 ; KNL-NEXT:    kmovw %k2, %eax
 ; KNL-NEXT:    movzbl %al, %eax
@@ -349,9 +346,8 @@ define <16 x double> @test16(double* %base, <16 x double> %src0, <16 x i32> %tri
 define void @test17(float* %base, <32 x float> %V, <32 x i32> %trigger) {
 ; SKX-LABEL: test17:
 ; SKX:       # %bb.0:
-; SKX-NEXT:    vpxor %xmm4, %xmm4, %xmm4
-; SKX-NEXT:    vpcmpeqd %zmm4, %zmm3, %k1
-; SKX-NEXT:    vpcmpeqd %zmm4, %zmm2, %k2
+; SKX-NEXT:    vptestnmd %zmm3, %zmm3, %k1
+; SKX-NEXT:    vptestnmd %zmm2, %zmm2, %k2
 ; SKX-NEXT:    kmovw %k2, %eax
 ; SKX-NEXT:    popcntl %eax, %eax
 ; SKX-NEXT:    vcompressps %zmm1, (%rdi,%rax,4) {%k1}
@@ -361,9 +357,8 @@ define void @test17(float* %base, <32 x float> %V, <32 x i32> %trigger) {
 ;
 ; KNL-LABEL: test17:
 ; KNL:       # %bb.0:
-; KNL-NEXT:    vpxor %xmm4, %xmm4, %xmm4
-; KNL-NEXT:    vpcmpeqd %zmm4, %zmm3, %k1
-; KNL-NEXT:    vpcmpeqd %zmm4, %zmm2, %k2
+; KNL-NEXT:    vptestnmd %zmm3, %zmm3, %k1
+; KNL-NEXT:    vptestnmd %zmm2, %zmm2, %k2
 ; KNL-NEXT:    kmovw %k2, %eax
 ; KNL-NEXT:    popcntl %eax, %eax
 ; KNL-NEXT:    vcompressps %zmm1, (%rdi,%rax,4) {%k1}