[X86] In lowerVectorShuffleAsElementInsertion, if were able to find a scalar i8 or i16 and need to zero extend it, make sure we use a vXi32 type of the full vector width.

Previously, this was hardcoded to v4i32, but if the input type is 256 bits we need to use v8i32.

Fixes PR35443

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319208 91177308-0d34-0410-b5e6-96231b3b80d8

Author: topperc

lib/Target/X86/X86ISelLowering.cpp

@@ -10149,7 +10149,7 @@ static SDValue lowerVectorShuffleAsElementInsertion(
         return SDValue();
 
       // Zero-extend directly to i32.
-      ExtVT = MVT::v4i32;
+      ExtVT = MVT::getVectorVT(MVT::i32, ExtVT.getSizeInBits() / 32);
       V2S = DAG.getNode(ISD::ZERO_EXTEND, DL, MVT::i32, V2S);
     }
     V2 = DAG.getNode(ISD::SCALAR_TO_VECTOR, DL, ExtVT, V2S);

test/CodeGen/X86/pr35443.ll

@@ -0,0 +1,30 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc < %s -mtriple=x86_64-unknown -mcpu=skx | FileCheck %s
+
+@ac = external local_unnamed_addr global [20 x i8], align 16
+@ai3 = external local_unnamed_addr global [20 x i32], align 16
+
+; Function Attrs: norecurse nounwind uwtable
+define void @main() {
+; CHECK-LABEL: main:
+; CHECK:       # BB#0: # %entry
+; CHECK-NEXT:    movzbl ac+{{.*}}(%rip), %eax
+; CHECK-NEXT:    vmovd %eax, %xmm0
+; CHECK-NEXT:    vpxor %xmm1, %xmm1, %xmm1
+; CHECK-NEXT:    vpsubq %ymm0, %ymm1, %ymm0
+; CHECK-NEXT:    vpmovqd %ymm0, ai3+{{.*}}(%rip)
+; CHECK-NEXT:    vzeroupper
+; CHECK-NEXT:    retq
+entry:
+  %wide.masked.load66 = call <4 x i8> @llvm.masked.load.v4i8.p0v4i8(<4 x i8>* bitcast (i8* getelementptr inbounds ([20 x i8], [20 x i8]* @ac, i64 0, i64 4) to <4 x i8>*), i32 1, <4 x i1> <i1 true, i1 false, i1 false, i1 false>, <4 x i8> undef)
+  %0 = zext <4 x i8> %wide.masked.load66 to <4 x i64>
+  %1 = sub <4 x i64> zeroinitializer, %0
+  %predphi = shufflevector <4 x i64> %1, <4 x i64> undef, <4 x i32> <i32 0, i32 5, i32 6, i32 7>
+  %2 = trunc <4 x i64> %predphi to <4 x i32>
+  %3 = add <4 x i32> zeroinitializer, %2
+  store <4 x i32> %3, <4 x i32>* bitcast (i32* getelementptr inbounds ([20 x i32], [20 x i32]* @ai3, i64 0, i64 4) to <4 x i32>*), align 16
+  ret void
+}
+
+; Function Attrs: argmemonly nounwind readonly
+declare <4 x i8> @llvm.masked.load.v4i8.p0v4i8(<4 x i8>*, i32, <4 x i1>, <4 x i8>)