Add handling of x86_avx2_pmovmskb to computeMaskedBitsForTargetNode for consistency. Add comments and an assert for BMI instructions to PerformXorCombine since the enabling of the combine is conditional on it, but the function itself isn't.

llvm-svn: 147287

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index b1971c1c5a7..16a3d090e9e 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -12621,7 +12621,8 @@ void X86TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
     case Intrinsic::x86_sse2_movmsk_pd:
     case Intrinsic::x86_avx_movmsk_pd_256:
     case Intrinsic::x86_mmx_pmovmskb:
-    case Intrinsic::x86_sse2_pmovmskb_128: {
+    case Intrinsic::x86_sse2_pmovmskb_128:
+    case Intrinsic::x86_avx2_pmovmskb: {
       // High bits of movmskp{s|d}, pmovmskb are known zero.
       switch (IntId) {
         case Intrinsic::x86_sse_movmsk_ps:      NumLoBits = 4; break;
@@ -12630,6 +12631,7 @@ void X86TargetLowering::computeMaskedBitsForTargetNode(const SDValue Op,
         case Intrinsic::x86_avx_movmsk_pd_256:  NumLoBits = 4; break;
         case Intrinsic::x86_mmx_pmovmskb:       NumLoBits = 8; break;
         case Intrinsic::x86_sse2_pmovmskb_128:  NumLoBits = 16; break;
+        case Intrinsic::x86_avx2_pmovmskb:      NumLoBits = 32; break;
       }
       KnownZero = APInt::getHighBitsSet(Mask.getBitWidth(),
                                         Mask.getBitWidth() - NumLoBits);
@@ -13856,6 +13858,7 @@ static SDValue PerformOrCombine(SDNode *N, SelectionDAG &DAG,
   return SDValue();
 }
 
+// PerformXorCombine - Attempts to turn XOR nodes into BLSMSK nodes
 static SDValue PerformXorCombine(SDNode *N, SelectionDAG &DAG,
                                  TargetLowering::DAGCombinerInfo &DCI,
                                  const X86Subtarget *Subtarget) {
@@ -13867,6 +13870,8 @@ static SDValue PerformXorCombine(SDNode *N, SelectionDAG &DAG,
   if (VT != MVT::i32 && VT != MVT::i64)
     return SDValue();
 
+  assert(Subtarget->hasBMI() && "Creating BLSMSK requires BMI instructions");
+
   // Create BLSMSK instructions by finding X ^ (X-1)
   SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);