[X86] combineCMP - use widenMaskVector to allow us to handle sub-i8 m…

…ask cases when just comparing a bool element against zero

llvm/lib/Target/X86/X86ISelLowering.cpp

@@ -53455,7 +53455,8 @@ static bool onlyZeroFlagUsed(SDValue Flags) {
   return true;
 }
 
-static SDValue combineCMP(SDNode *N, SelectionDAG &DAG) {
+static SDValue combineCMP(SDNode *N, SelectionDAG &DAG,
+                          const X86Subtarget &Subtarget) {
   // Only handle test patterns.
   if (!isNullConstant(N->getOperand(1)))
     return SDValue();
@@ -53493,7 +53494,6 @@ static SDValue combineCMP(SDNode *N, SelectionDAG &DAG) {
 
   // If we're extracting from a avx512 bool vector and comparing against zero,
   // then try to just bitcast the vector to an integer to use TEST/BT directly.
-  // TODO: Handle v2i1/v4i1 bool vector cases.
   // (and (extract_elt (kshiftr vXi1, C), 0), 1) -> (and (bc vXi1), 1<<C)
   if (Op.getOpcode() == ISD::AND && isOneConstant(Op.getOperand(1)) &&
       Op.hasOneUse() && onlyZeroFlagUsed(SDValue(N, 0))) {
@@ -53502,16 +53502,16 @@ static SDValue combineCMP(SDNode *N, SelectionDAG &DAG) {
         isNullConstant(Src.getOperand(1)) &&
         Src.getOperand(0).getValueType().getScalarType() == MVT::i1) {
       SDValue BoolVec = Src.getOperand(0);
+      unsigned ShAmt = 0;
+      if (BoolVec.getOpcode() == X86ISD::KSHIFTR) {
+        ShAmt = BoolVec.getConstantOperandVal(1);
+        BoolVec = BoolVec.getOperand(0);
+      }
+      BoolVec = widenMaskVector(BoolVec, false, Subtarget, DAG, dl);
       EVT VecVT = BoolVec.getValueType();
       unsigned BitWidth = VecVT.getVectorNumElements();
       EVT BCVT = EVT::getIntegerVT(*DAG.getContext(), BitWidth);
       if (TLI.isTypeLegal(VecVT) && TLI.isTypeLegal(BCVT)) {
-        unsigned ShAmt = 0;
-        if (BoolVec.getOpcode() == X86ISD::KSHIFTR &&
-            BoolVec.getConstantOperandAPInt(1).ult(BitWidth)) {
-          ShAmt = BoolVec.getConstantOperandVal(1);
-          BoolVec = BoolVec.getOperand(0);
-        }
         APInt Mask = APInt::getOneBitSet(BitWidth, ShAmt);
         Op = DAG.getBitcast(BCVT, BoolVec);
         Op = DAG.getNode(ISD::AND, dl, BCVT, Op,
@@ -55800,7 +55800,7 @@ SDValue X86TargetLowering::PerformDAGCombine(SDNode *N,
   case X86ISD::BLENDV:      return combineSelect(N, DAG, DCI, Subtarget);
   case ISD::BITCAST:        return combineBitcast(N, DAG, DCI, Subtarget);
   case X86ISD::CMOV:        return combineCMov(N, DAG, DCI, Subtarget);
-  case X86ISD::CMP:         return combineCMP(N, DAG);
+  case X86ISD::CMP:         return combineCMP(N, DAG, Subtarget);
   case ISD::ADD:            return combineAdd(N, DAG, DCI, Subtarget);
   case ISD::SUB:            return combineSub(N, DAG, DCI, Subtarget);
   case X86ISD::ADD:

llvm/test/CodeGen/X86/movmsk-cmp.ll

@@ -4351,8 +4351,7 @@ define i32 @PR39665_c_ray(<2 x double> %x, <2 x double> %y) {
 ; KNL-NEXT:    # kill: def $xmm0 killed $xmm0 def $zmm0
 ; KNL-NEXT:    vcmpltpd %zmm0, %zmm1, %k0
 ; KNL-NEXT:    kmovw %k0, %ecx
-; KNL-NEXT:    kmovw %k0, %eax
-; KNL-NEXT:    testb $2, %al
+; KNL-NEXT:    testb $2, %cl
 ; KNL-NEXT:    movl $42, %eax
 ; KNL-NEXT:    movl $99, %edx
 ; KNL-NEXT:    cmovel %edx, %eax
@@ -4365,8 +4364,7 @@ define i32 @PR39665_c_ray(<2 x double> %x, <2 x double> %y) {
 ; SKX:       # %bb.0:
 ; SKX-NEXT:    vcmpltpd %xmm0, %xmm1, %k0
 ; SKX-NEXT:    kmovd %k0, %ecx
-; SKX-NEXT:    kmovd %k0, %eax
-; SKX-NEXT:    testb $2, %al
+; SKX-NEXT:    testb $2, %cl
 ; SKX-NEXT:    movl $42, %eax
 ; SKX-NEXT:    movl $99, %edx
 ; SKX-NEXT:    cmovel %edx, %eax

llvm/test/CodeGen/X86/pr33349.ll

@@ -12,8 +12,7 @@ target triple = "x86_64-unknown-linux-gnu"
 ; KNL-NEXT:    vptestmd %zmm0, %zmm0, %k0
 ; KNL-NEXT:    kshiftrw $2, %k0, %k1
 ; KNL-NEXT:    kmovw %k1, %eax
-; KNL-NEXT:    kmovw %k1, %ecx
-; KNL-NEXT:    testb $1, %cl
+; KNL-NEXT:    testb $1, %al
 ; KNL-NEXT:    fld1
 ; KNL-NEXT:    fldz
 ; KNL-NEXT:    fld %st(0)
@@ -22,8 +21,7 @@ target triple = "x86_64-unknown-linux-gnu"
 ; KNL-NEXT:    fld %st(1)
 ; KNL-NEXT:    fcmovne %st(3), %st
 ; KNL-NEXT:    kmovw %k0, %eax
-; KNL-NEXT:    kmovw %k0, %ecx
-; KNL-NEXT:    testb $1, %cl
+; KNL-NEXT:    testb $1, %al
 ; KNL-NEXT:    fld %st(2)
 ; KNL-NEXT:    fcmovne %st(4), %st
 ; KNL-NEXT:    testb $2, %al
@@ -46,8 +44,7 @@ target triple = "x86_64-unknown-linux-gnu"
 ; SKX-NEXT:    vpmovd2m %xmm0, %k0
 ; SKX-NEXT:    kshiftrb $2, %k0, %k1
 ; SKX-NEXT:    kmovd %k1, %eax
-; SKX-NEXT:    kmovd %k1, %ecx
-; SKX-NEXT:    testb $1, %cl
+; SKX-NEXT:    testb $1, %al
 ; SKX-NEXT:    fld1
 ; SKX-NEXT:    fldz
 ; SKX-NEXT:    fld %st(0)
@@ -56,8 +53,7 @@ target triple = "x86_64-unknown-linux-gnu"
 ; SKX-NEXT:    fld %st(1)
 ; SKX-NEXT:    fcmovne %st(3), %st
 ; SKX-NEXT:    kmovd %k0, %eax
-; SKX-NEXT:    kmovd %k0, %ecx
-; SKX-NEXT:    testb $1, %cl
+; SKX-NEXT:    testb $1, %al
 ; SKX-NEXT:    fld %st(2)
 ; SKX-NEXT:    fcmovne %st(4), %st
 ; SKX-NEXT:    testb $2, %al

llvm/test/CodeGen/X86/pr34177.ll

@@ -49,10 +49,9 @@ define void @test(<4 x i64> %a, <4 x x86_fp80> %b, ptr %c) local_unnamed_addr {
 ; AVX512VL-LABEL: test:
 ; AVX512VL:       # %bb.0:
 ; AVX512VL-NEXT:    vpcmpeqq {{\.?LCPI[0-9]+_[0-9]+}}(%rip), %ymm0, %k0
-; AVX512VL-NEXT:    kmovd %k0, %eax
 ; AVX512VL-NEXT:    kshiftrb $2, %k0, %k1
-; AVX512VL-NEXT:    kmovd %k0, %ecx
-; AVX512VL-NEXT:    testb $2, %cl
+; AVX512VL-NEXT:    kmovd %k0, %eax
+; AVX512VL-NEXT:    testb $2, %al
 ; AVX512VL-NEXT:    fld1
 ; AVX512VL-NEXT:    fldz
 ; AVX512VL-NEXT:    fld %st(0)
@@ -61,8 +60,7 @@ define void @test(<4 x i64> %a, <4 x x86_fp80> %b, ptr %c) local_unnamed_addr {
 ; AVX512VL-NEXT:    fld %st(1)
 ; AVX512VL-NEXT:    fcmovne %st(3), %st
 ; AVX512VL-NEXT:    kmovd %k1, %eax
-; AVX512VL-NEXT:    kmovd %k1, %ecx
-; AVX512VL-NEXT:    testb $2, %cl
+; AVX512VL-NEXT:    testb $2, %al
 ; AVX512VL-NEXT:    fld %st(2)
 ; AVX512VL-NEXT:    fcmovne %st(4), %st
 ; AVX512VL-NEXT:    testb $1, %al