X86: use getConstant rather than getTargetConstant behind BUILD_VECTOR.

getTargetConstant should only be used when you can guarantee the instruction
selected will be able to cope with the raw value. BUILD_VECTOR is rather too
generic for this so we should use getConstant instead. In that case, an
instruction can still consume the constant, but if it doesn't it'll be
materialised through its own round of ISel.

Should fix PR21352.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221961 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/X86ISelLowering.cpp b/lib/Target/X86/X86ISelLowering.cpp
index 92cbbe68a28fd9398ef4bb3039d414d1660fe816..2f38b639ca24869df7b163a090b17f6cc0bbd435 100644 (file)
--- a/lib/Target/X86/X86ISelLowering.cpp
+++ b/lib/Target/X86/X86ISelLowering.cpp
@@ -5062,32 +5062,32 @@ static SDValue getZeroVector(EVT VT, const X86Subtarget *Subtarget,
   SDValue Vec;
   if (VT.is128BitVector()) {  // SSE
     if (Subtarget->hasSSE2()) {  // SSE2
-      SDValue Cst = DAG.getTargetConstant(0, MVT::i32);
+      SDValue Cst = DAG.getConstant(0, MVT::i32);
       Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4i32, Cst, Cst, Cst, Cst);
     } else { // SSE1
-      SDValue Cst = DAG.getTargetConstantFP(+0.0, MVT::f32);
+      SDValue Cst = DAG.getConstantFP(+0.0, MVT::f32);
       Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v4f32, Cst, Cst, Cst, Cst);
     }
   } else if (VT.is256BitVector()) { // AVX
     if (Subtarget->hasInt256()) { // AVX2
-      SDValue Cst = DAG.getTargetConstant(0, MVT::i32);
+      SDValue Cst = DAG.getConstant(0, MVT::i32);
       SDValue Ops[] = { Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst };
       Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v8i32, Ops);
     } else {
       // 256-bit logic and arithmetic instructions in AVX are all
       // floating-point, no support for integer ops. Emit fp zeroed vectors.
-      SDValue Cst = DAG.getTargetConstantFP(+0.0, MVT::f32);
+      SDValue Cst = DAG.getConstantFP(+0.0, MVT::f32);
       SDValue Ops[] = { Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst };
       Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v8f32, Ops);
     }
   } else if (VT.is512BitVector()) { // AVX-512
-      SDValue Cst = DAG.getTargetConstant(0, MVT::i32);
+      SDValue Cst = DAG.getConstant(0, MVT::i32);
       SDValue Ops[] = { Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst,
                         Cst, Cst, Cst, Cst, Cst, Cst, Cst, Cst };
       Vec = DAG.getNode(ISD::BUILD_VECTOR, dl, MVT::v16i32, Ops);
   } else if (VT.getScalarType() == MVT::i1) {
     assert(VT.getVectorNumElements() <= 16 && "Unexpected vector type");
-    SDValue Cst = DAG.getTargetConstant(0, MVT::i1);
+    SDValue Cst = DAG.getConstant(0, MVT::i1);
     SmallVector<SDValue, 16> Ops(VT.getVectorNumElements(), Cst);
     return DAG.getNode(ISD::BUILD_VECTOR, dl, VT, Ops);
   } else
@@ -5104,7 +5104,7 @@ static SDValue getOnesVector(MVT VT, bool HasInt256, SelectionDAG &DAG,
                              SDLoc dl) {
   assert(VT.isVector() && "Expected a vector type");
 
-  SDValue Cst = DAG.getTargetConstant(~0U, MVT::i32);
+  SDValue Cst = DAG.getConstant(~0U, MVT::i32);
   SDValue Vec;
   if (VT.is256BitVector()) {
     if (HasInt256) { // AVX2

diff --git a/test/CodeGen/X86/vector-shuffle-128-v16.ll b/test/CodeGen/X86/vector-shuffle-128-v16.ll
index 312f1291756b65751361968aef9c53f198a986ad..fb4cc7a367ebb1b214c0d9458227a9f6bc16fbfc 100644 (file)
--- a/test/CodeGen/X86/vector-shuffle-128-v16.ll
+++ b/test/CodeGen/X86/vector-shuffle-128-v16.ll
@@ -1219,3 +1219,14 @@ entry:
 
   ret <16 x i8> %s.2.0
 }
+
+define void @constant_gets_selected() {
+; ALL-LABEL: constant_gets_selected:
+; ALL-NOT movd $0, {{%xmm[0-9]+}}
+  %weird_zero = bitcast <4 x i32> zeroinitializer to <16 x i8>
+  %shuffle.i = shufflevector <16 x i8> <i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 undef, i8 0, i8 0, i8 0, i8 0>, <16 x i8> %weird_zero, <16 x i32> <i32 12, i32 13, i32 14, i32 15, i32 16, i32 17, i32 18, i32 19, i32 20, i32 21, i32 22, i32 23, i32 24, i32 25, i32 26, i32 27>
+  %weirder_zero = bitcast <16 x i8> %shuffle.i to <4 x i32>
+  store <4 x i32> %weirder_zero, <4 x i32>* undef, align 16
+  store <4 x i32> zeroinitializer, <4 x i32>* undef, align 16
+  ret void
+}