[llvm] 7c2f0dc - [X86] combinePredicateReduction - ensure non-i8 scalar type is a multiple of 8 bits

[Simon Pilgrim via llvm-commits]

Author: Simon Pilgrim
Date: 2023-01-11T14:19:33Z
New Revision: 7c2f0dc97036f1b2ed1db68d56019e737d420633

URL: https://github.com/llvm/llvm-project/commit/7c2f0dc97036f1b2ed1db68d56019e737d420633
DIFF: https://github.com/llvm/llvm-project/commit/7c2f0dc97036f1b2ed1db68d56019e737d420633.diff

LOG: [X86] combinePredicateReduction - ensure non-i8 scalar type is a multiple of 8 bits

For the "all_of(setcc(x,y,eq)) -> PMOVMSKB(PCMPEQB())" fold, we failed to ensure that we could safely bitcast to <X x i8>, which in particular failed with boolean types

Thanks to @lerno for catching this and providing the test case

Added: 
    

Modified: 
    llvm/lib/Target/X86/X86ISelLowering.cpp
    llvm/test/CodeGen/X86/vector-reduce-and-bool.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index bed3e94f9dde1..a2976a86327d9 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -43998,7 +43998,7 @@ static SDValue combinePredicateReduction(SDNode *Extract, SelectionDAG &DAG,
           cast<CondCodeSDNode>(Match.getOperand(2))->get() ==
               ISD::CondCode::SETEQ) {
         EVT VecSVT = Match.getOperand(0).getValueType().getScalarType();
-        if (VecSVT != MVT::i8) {
+        if (VecSVT != MVT::i8 && (VecSVT.getSizeInBits() % 8) == 0) {
           NumElts *= VecSVT.getSizeInBits() / 8;
           EVT CmpVT = EVT::getVectorVT(*DAG.getContext(), MVT::i8, NumElts);
           MatchVT = EVT::getVectorVT(*DAG.getContext(), MVT::i1, NumElts);

diff  --git a/llvm/test/CodeGen/X86/vector-reduce-and-bool.ll b/llvm/test/CodeGen/X86/vector-reduce-and-bool.ll
index 44c5d05e81e03..30f7a96bfba9e 100644
--- a/llvm/test/CodeGen/X86/vector-reduce-and-bool.ll
+++ b/llvm/test/CodeGen/X86/vector-reduce-and-bool.ll
@@ -1563,6 +1563,79 @@ define i1 @icmp0_v64i8_v64i1(<64 x i8>) {
   ret i1 %b
 }
 
+define i8 @icmp0_v8i1(<8 x i8>) {
+; SSE2-LABEL: icmp0_v8i1:
+; SSE2:       # %bb.0:
+; SSE2-NEXT:    punpcklbw {{.*#+}} xmm0 = xmm0[0,0,1,1,2,2,3,3,4,4,5,5,6,6,7,7]
+; SSE2-NEXT:    pcmpeqd %xmm1, %xmm1
+; SSE2-NEXT:    pxor %xmm0, %xmm1
+; SSE2-NEXT:    psllw $15, %xmm1
+; SSE2-NEXT:    packsswb %xmm1, %xmm1
+; SSE2-NEXT:    pmovmskb %xmm1, %eax
+; SSE2-NEXT:    cmpb $-1, %al
+; SSE2-NEXT:    sete %al
+; SSE2-NEXT:    retq
+;
+; SSE41-LABEL: icmp0_v8i1:
+; SSE41:       # %bb.0:
+; SSE41-NEXT:    pmovzxbw {{.*#+}} xmm0 = xmm0[0],zero,xmm0[1],zero,xmm0[2],zero,xmm0[3],zero,xmm0[4],zero,xmm0[5],zero,xmm0[6],zero,xmm0[7],zero
+; SSE41-NEXT:    pcmpeqd %xmm1, %xmm1
+; SSE41-NEXT:    pxor %xmm0, %xmm1
+; SSE41-NEXT:    psllw $15, %xmm1
+; SSE41-NEXT:    packsswb %xmm1, %xmm1
+; SSE41-NEXT:    pmovmskb %xmm1, %eax
+; SSE41-NEXT:    cmpb $-1, %al
+; SSE41-NEXT:    sete %al
+; SSE41-NEXT:    retq
+;
+; AVX-LABEL: icmp0_v8i1:
+; AVX:       # %bb.0:
+; AVX-NEXT:    vpmovzxbw {{.*#+}} xmm0 = xmm0[0],zero,xmm0[1],zero,xmm0[2],zero,xmm0[3],zero,xmm0[4],zero,xmm0[5],zero,xmm0[6],zero,xmm0[7],zero
+; AVX-NEXT:    vpcmpeqd %xmm1, %xmm1, %xmm1
+; AVX-NEXT:    vpxor %xmm1, %xmm0, %xmm0
+; AVX-NEXT:    vpsllw $15, %xmm0, %xmm0
+; AVX-NEXT:    vpacksswb %xmm0, %xmm0, %xmm0
+; AVX-NEXT:    vpmovmskb %xmm0, %eax
+; AVX-NEXT:    cmpb $-1, %al
+; AVX-NEXT:    sete %al
+; AVX-NEXT:    retq
+;
+; AVX512F-LABEL: icmp0_v8i1:
+; AVX512F:       # %bb.0:
+; AVX512F-NEXT:    vpmovsxbd %xmm0, %zmm0
+; AVX512F-NEXT:    vpslld $31, %zmm0, %zmm0
+; AVX512F-NEXT:    vptestmd %zmm0, %zmm0, %k0
+; AVX512F-NEXT:    kmovw %k0, %eax
+; AVX512F-NEXT:    testb %al, %al
+; AVX512F-NEXT:    sete %al
+; AVX512F-NEXT:    vzeroupper
+; AVX512F-NEXT:    retq
+;
+; AVX512BW-LABEL: icmp0_v8i1:
+; AVX512BW:       # %bb.0:
+; AVX512BW-NEXT:    vpsllw $7, %xmm0, %xmm0
+; AVX512BW-NEXT:    vpmovb2m %zmm0, %k0
+; AVX512BW-NEXT:    kmovd %k0, %eax
+; AVX512BW-NEXT:    testb %al, %al
+; AVX512BW-NEXT:    sete %al
+; AVX512BW-NEXT:    vzeroupper
+; AVX512BW-NEXT:    retq
+;
+; AVX512VL-LABEL: icmp0_v8i1:
+; AVX512VL:       # %bb.0:
+; AVX512VL-NEXT:    vpsllw $7, %xmm0, %xmm0
+; AVX512VL-NEXT:    vpmovb2m %xmm0, %k0
+; AVX512VL-NEXT:    kmovd %k0, %eax
+; AVX512VL-NEXT:    testb %al, %al
+; AVX512VL-NEXT:    sete %al
+; AVX512VL-NEXT:    retq
+  %a = trunc <8 x i8> %0 to <8 x i1>
+  %b = icmp eq <8 x i1> %a, zeroinitializer
+  %c = call i1 @llvm.vector.reduce.and.v8i1(<8 x i1> %b)
+  %d = zext i1 %c to i8
+  ret i8 %d
+}
+
 ;
 ; Comparison
 ;