Merging r343373:

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r343373 | rksimon | 2018-09-29 06:25:22 -0700 (Sat, 29 Sep 2018) | 3 lines

[X86][SSE] Fixed issue with v2i64 variable shifts on 32-bit targets

The shift amount might have peeked through a extract_subvector, altering the number of vector elements in the 'Amt' variable - so we were incorrectly calculating the ratio when peeking through bitcasts, resulting in incorrectly detecting splats.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_70@344810 91177308-0d34-0410-b5e6-96231b3b80d8

Author: tstellar

lib/Target/X86/X86ISelLowering.cpp

@@ -23312,15 +23312,14 @@ static SDValue LowerScalarVariableShift(SDValue Op, SelectionDAG &DAG,
   }
 
   // Check cases (mainly 32-bit) where i64 is expanded into high and low parts.
-  if (VT == MVT::v2i64  && Amt.getOpcode() == ISD::BITCAST &&
+  if (VT == MVT::v2i64 && Amt.getOpcode() == ISD::BITCAST &&
       Amt.getOperand(0).getOpcode() == ISD::BUILD_VECTOR) {
     Amt = Amt.getOperand(0);
-    unsigned Ratio = Amt.getSimpleValueType().getVectorNumElements() /
-                     VT.getVectorNumElements();
+    unsigned Ratio = 64 / Amt.getScalarValueSizeInBits();
     std::vector<SDValue> Vals(Ratio);
     for (unsigned i = 0; i != Ratio; ++i)
       Vals[i] = Amt.getOperand(i);
-    for (unsigned i = Ratio; i != Amt.getNumOperands(); i += Ratio) {
+    for (unsigned i = Ratio, e = Amt.getNumOperands(); i != e; i += Ratio) {
       for (unsigned j = 0; j != Ratio; ++j)
         if (Vals[j] != Amt.getOperand(i + j))
           return SDValue();

test/CodeGen/X86/known-signbits-vector.ll

@@ -381,19 +381,26 @@ define <4 x float> @signbits_ashr_sext_select_shuffle_sitofp(<4 x i64> %a0, <4 x
 ; X32-NEXT:    movl %esp, %ebp
 ; X32-NEXT:    andl $-16, %esp
 ; X32-NEXT:    subl $16, %esp
+; X32-NEXT:    vmovdqa {{.*#+}} xmm3 = [33,0,63,0]
+; X32-NEXT:    vmovdqa {{.*#+}} xmm4 = [0,2147483648,0,2147483648]
+; X32-NEXT:    vpsrlq %xmm3, %xmm4, %xmm5
+; X32-NEXT:    vpshufd {{.*#+}} xmm6 = xmm3[2,3,0,1]
+; X32-NEXT:    vpsrlq %xmm6, %xmm4, %xmm4
+; X32-NEXT:    vpblendw {{.*#+}} xmm4 = xmm5[0,1,2,3],xmm4[4,5,6,7]
+; X32-NEXT:    vextractf128 $1, %ymm2, %xmm5
+; X32-NEXT:    vpsrlq %xmm6, %xmm5, %xmm7
+; X32-NEXT:    vpsrlq %xmm3, %xmm5, %xmm5
+; X32-NEXT:    vpblendw {{.*#+}} xmm5 = xmm5[0,1,2,3],xmm7[4,5,6,7]
+; X32-NEXT:    vpsrlq %xmm6, %xmm2, %xmm6
+; X32-NEXT:    vpsrlq %xmm3, %xmm2, %xmm2
+; X32-NEXT:    vpblendw {{.*#+}} xmm2 = xmm2[0,1,2,3],xmm6[4,5,6,7]
 ; X32-NEXT:    vpmovsxdq 16(%ebp), %xmm3
+; X32-NEXT:    vpxor %xmm4, %xmm5, %xmm5
+; X32-NEXT:    vpsubq %xmm4, %xmm5, %xmm5
+; X32-NEXT:    vpxor %xmm4, %xmm2, %xmm2
+; X32-NEXT:    vpsubq %xmm4, %xmm2, %xmm2
 ; X32-NEXT:    vpmovsxdq 8(%ebp), %xmm4
-; X32-NEXT:    vmovdqa {{.*#+}} xmm5 = [33,0,63,0]
-; X32-NEXT:    vmovdqa {{.*#+}} xmm6 = [0,2147483648,0,2147483648]
-; X32-NEXT:    vpsrlq %xmm5, %xmm6, %xmm6
-; X32-NEXT:    vextractf128 $1, %ymm2, %xmm7
-; X32-NEXT:    vpsrlq %xmm5, %xmm7, %xmm7
-; X32-NEXT:    vpxor %xmm6, %xmm7, %xmm7
-; X32-NEXT:    vpsubq %xmm6, %xmm7, %xmm7
-; X32-NEXT:    vpsrlq %xmm5, %xmm2, %xmm2
-; X32-NEXT:    vpxor %xmm6, %xmm2, %xmm2
-; X32-NEXT:    vpsubq %xmm6, %xmm2, %xmm2
-; X32-NEXT:    vinsertf128 $1, %xmm7, %ymm2, %ymm2
+; X32-NEXT:    vinsertf128 $1, %xmm5, %ymm2, %ymm2
 ; X32-NEXT:    vinsertf128 $1, %xmm3, %ymm4, %ymm3
 ; X32-NEXT:    vextractf128 $1, %ymm1, %xmm4
 ; X32-NEXT:    vextractf128 $1, %ymm0, %xmm5