[LoopVectorize] Fix VPRecipeBuilder::createEdgeMask to correctly generate the mask

This patch fixes pr48832 by correctly generating the mask when a poison value is involved.

Consider this CFG (which is a part of the input):

```
for.body:                                         ; preds = %for.cond
  br i1 true, label %cond.false, label %land.rhs

land.rhs:                                         ; preds = %for.body
  br i1 poison, label %cond.end, label %cond.false

cond.false:                                       ; preds = %for.body, %land.rhs
  br label %cond.end

cond.end:                                         ; preds = %land.rhs, %cond.false
  %cond = phi i32 [ 0, %cond.false ], [ 1, %land.rhs ]

```

The path for.body -> land.rhs -> cond.end should be taken when 'select i1 false, i1 poison, i1 false' holds (which means it's never taken); but VPRecipeBuilder::createEdgeMask was emitting 'and i1 false, poison' instead.
The former one successfully blocks poison propagation whereas the latter one doesn't, making the condition poison and thus causing the miscompilation.

SimplifyCFG has a similar bug (which didn't expose a real-world bug yet), and a patch for this is also ongoing (see https://reviews.llvm.org/D95026).

Reviewed By: bjope

Differential Revision: https://reviews.llvm.org/D95217

(cherry picked from commit ed253ef)

Author: aqjune

llvm/lib/Transforms/Vectorize/LoopVectorizationPlanner.h

@@ -142,6 +142,10 @@ class VPBuilder {
     return createInstruction(Instruction::BinaryOps::Or, {LHS, RHS});
   }
 
+  VPValue *createSelect(VPValue *Cond, VPValue *TrueVal, VPValue *FalseVal) {
+    return createNaryOp(Instruction::Select, {Cond, TrueVal, FalseVal});
+  }
+
   //===--------------------------------------------------------------------===//
   // RAII helpers.
   //===--------------------------------------------------------------------===//

llvm/lib/Transforms/Vectorize/LoopVectorize.cpp

@@ -8195,8 +8195,15 @@ VPValue *VPRecipeBuilder::createEdgeMask(BasicBlock *Src, BasicBlock *Dst,
   if (BI->getSuccessor(0) != Dst)
     EdgeMask = Builder.createNot(EdgeMask);
 
-  if (SrcMask) // Otherwise block in-mask is all-one, no need to AND.
-    EdgeMask = Builder.createAnd(EdgeMask, SrcMask);
+  if (SrcMask) { // Otherwise block in-mask is all-one, no need to AND.
+    // The condition is 'SrcMask && EdgeMask', which is equivalent to
+    // 'select i1 SrcMask, i1 EdgeMask, i1 false'.
+    // The select version does not introduce new UB if SrcMask is false and
+    // EdgeMask is poison. Using 'and' here introduces undefined behavior.
+    VPValue *False = Plan->getOrAddVPValue(
+        ConstantInt::getFalse(BI->getCondition()->getType()));
+    EdgeMask = Builder.createSelect(SrcMask, EdgeMask, False);
+  }
 
   return EdgeMaskCache[Edge] = EdgeMask;
 }

llvm/test/Transforms/LoopVectorize/X86/masked_load_store.ll

@@ -2042,10 +2042,10 @@ define void @foo7(double* noalias nocapture %out, double** noalias nocapture rea
 ; AVX1-NEXT:    [[TMP49:%.*]] = xor <4 x i1> [[TMP41]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX1-NEXT:    [[TMP50:%.*]] = xor <4 x i1> [[TMP42]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX1-NEXT:    [[TMP51:%.*]] = xor <4 x i1> [[TMP43]], <i1 true, i1 true, i1 true, i1 true>
-; AVX1-NEXT:    [[TMP52:%.*]] = and <4 x i1> [[TMP48]], [[TMP28]]
-; AVX1-NEXT:    [[TMP53:%.*]] = and <4 x i1> [[TMP49]], [[TMP29]]
-; AVX1-NEXT:    [[TMP54:%.*]] = and <4 x i1> [[TMP50]], [[TMP30]]
-; AVX1-NEXT:    [[TMP55:%.*]] = and <4 x i1> [[TMP51]], [[TMP31]]
+; AVX1-NEXT:    [[TMP52:%.*]] = select <4 x i1> [[TMP28]], <4 x i1> [[TMP48]], <4 x i1> zeroinitializer
+; AVX1-NEXT:    [[TMP53:%.*]] = select <4 x i1> [[TMP29]], <4 x i1> [[TMP49]], <4 x i1> zeroinitializer
+; AVX1-NEXT:    [[TMP54:%.*]] = select <4 x i1> [[TMP30]], <4 x i1> [[TMP50]], <4 x i1> zeroinitializer
+; AVX1-NEXT:    [[TMP55:%.*]] = select <4 x i1> [[TMP31]], <4 x i1> [[TMP51]], <4 x i1> zeroinitializer
 ; AVX1-NEXT:    [[TMP56:%.*]] = getelementptr inbounds double, double* [[TMP44]], i32 0
 ; AVX1-NEXT:    [[TMP57:%.*]] = bitcast double* [[TMP56]] to <4 x double>*
 ; AVX1-NEXT:    call void @llvm.masked.store.v4f64.p0v4f64(<4 x double> <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>, <4 x double>* [[TMP57]], i32 8, <4 x i1> [[TMP52]])
@@ -2166,10 +2166,10 @@ define void @foo7(double* noalias nocapture %out, double** noalias nocapture rea
 ; AVX2-NEXT:    [[TMP49:%.*]] = xor <4 x i1> [[TMP41]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX2-NEXT:    [[TMP50:%.*]] = xor <4 x i1> [[TMP42]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX2-NEXT:    [[TMP51:%.*]] = xor <4 x i1> [[TMP43]], <i1 true, i1 true, i1 true, i1 true>
-; AVX2-NEXT:    [[TMP52:%.*]] = and <4 x i1> [[TMP48]], [[TMP28]]
-; AVX2-NEXT:    [[TMP53:%.*]] = and <4 x i1> [[TMP49]], [[TMP29]]
-; AVX2-NEXT:    [[TMP54:%.*]] = and <4 x i1> [[TMP50]], [[TMP30]]
-; AVX2-NEXT:    [[TMP55:%.*]] = and <4 x i1> [[TMP51]], [[TMP31]]
+; AVX2-NEXT:    [[TMP52:%.*]] = select <4 x i1> [[TMP28]], <4 x i1> [[TMP48]], <4 x i1> zeroinitializer
+; AVX2-NEXT:    [[TMP53:%.*]] = select <4 x i1> [[TMP29]], <4 x i1> [[TMP49]], <4 x i1> zeroinitializer
+; AVX2-NEXT:    [[TMP54:%.*]] = select <4 x i1> [[TMP30]], <4 x i1> [[TMP50]], <4 x i1> zeroinitializer
+; AVX2-NEXT:    [[TMP55:%.*]] = select <4 x i1> [[TMP31]], <4 x i1> [[TMP51]], <4 x i1> zeroinitializer
 ; AVX2-NEXT:    [[TMP56:%.*]] = getelementptr inbounds double, double* [[TMP44]], i32 0
 ; AVX2-NEXT:    [[TMP57:%.*]] = bitcast double* [[TMP56]] to <4 x double>*
 ; AVX2-NEXT:    call void @llvm.masked.store.v4f64.p0v4f64(<4 x double> <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>, <4 x double>* [[TMP57]], i32 8, <4 x i1> [[TMP52]])
@@ -2290,10 +2290,10 @@ define void @foo7(double* noalias nocapture %out, double** noalias nocapture rea
 ; AVX512-NEXT:    [[TMP49:%.*]] = xor <8 x i1> [[TMP41]], <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>
 ; AVX512-NEXT:    [[TMP50:%.*]] = xor <8 x i1> [[TMP42]], <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>
 ; AVX512-NEXT:    [[TMP51:%.*]] = xor <8 x i1> [[TMP43]], <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>
-; AVX512-NEXT:    [[TMP52:%.*]] = and <8 x i1> [[TMP48]], [[TMP28]]
-; AVX512-NEXT:    [[TMP53:%.*]] = and <8 x i1> [[TMP49]], [[TMP29]]
-; AVX512-NEXT:    [[TMP54:%.*]] = and <8 x i1> [[TMP50]], [[TMP30]]
-; AVX512-NEXT:    [[TMP55:%.*]] = and <8 x i1> [[TMP51]], [[TMP31]]
+; AVX512-NEXT:    [[TMP52:%.*]] = select <8 x i1> [[TMP28]], <8 x i1> [[TMP48]], <8 x i1> zeroinitializer
+; AVX512-NEXT:    [[TMP53:%.*]] = select <8 x i1> [[TMP29]], <8 x i1> [[TMP49]], <8 x i1> zeroinitializer
+; AVX512-NEXT:    [[TMP54:%.*]] = select <8 x i1> [[TMP30]], <8 x i1> [[TMP50]], <8 x i1> zeroinitializer
+; AVX512-NEXT:    [[TMP55:%.*]] = select <8 x i1> [[TMP31]], <8 x i1> [[TMP51]], <8 x i1> zeroinitializer
 ; AVX512-NEXT:    [[TMP56:%.*]] = getelementptr inbounds double, double* [[TMP44]], i32 0
 ; AVX512-NEXT:    [[TMP57:%.*]] = bitcast double* [[TMP56]] to <8 x double>*
 ; AVX512-NEXT:    call void @llvm.masked.store.v8f64.p0v8f64(<8 x double> <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>, <8 x double>* [[TMP57]], i32 8, <8 x i1> [[TMP52]])
@@ -2459,10 +2459,10 @@ define void @foo8(double* noalias nocapture %out, i32 ()** noalias nocapture rea
 ; AVX1-NEXT:    [[TMP49:%.*]] = xor <4 x i1> [[TMP41]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX1-NEXT:    [[TMP50:%.*]] = xor <4 x i1> [[TMP42]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX1-NEXT:    [[TMP51:%.*]] = xor <4 x i1> [[TMP43]], <i1 true, i1 true, i1 true, i1 true>
-; AVX1-NEXT:    [[TMP52:%.*]] = and <4 x i1> [[TMP48]], [[TMP28]]
-; AVX1-NEXT:    [[TMP53:%.*]] = and <4 x i1> [[TMP49]], [[TMP29]]
-; AVX1-NEXT:    [[TMP54:%.*]] = and <4 x i1> [[TMP50]], [[TMP30]]
-; AVX1-NEXT:    [[TMP55:%.*]] = and <4 x i1> [[TMP51]], [[TMP31]]
+; AVX1-NEXT:    [[TMP52:%.*]] = select <4 x i1> [[TMP28]], <4 x i1> [[TMP48]], <4 x i1> zeroinitializer
+; AVX1-NEXT:    [[TMP53:%.*]] = select <4 x i1> [[TMP29]], <4 x i1> [[TMP49]], <4 x i1> zeroinitializer
+; AVX1-NEXT:    [[TMP54:%.*]] = select <4 x i1> [[TMP30]], <4 x i1> [[TMP50]], <4 x i1> zeroinitializer
+; AVX1-NEXT:    [[TMP55:%.*]] = select <4 x i1> [[TMP31]], <4 x i1> [[TMP51]], <4 x i1> zeroinitializer
 ; AVX1-NEXT:    [[TMP56:%.*]] = getelementptr inbounds double, double* [[TMP44]], i32 0
 ; AVX1-NEXT:    [[TMP57:%.*]] = bitcast double* [[TMP56]] to <4 x double>*
 ; AVX1-NEXT:    call void @llvm.masked.store.v4f64.p0v4f64(<4 x double> <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>, <4 x double>* [[TMP57]], i32 8, <4 x i1> [[TMP52]])
@@ -2583,10 +2583,10 @@ define void @foo8(double* noalias nocapture %out, i32 ()** noalias nocapture rea
 ; AVX2-NEXT:    [[TMP49:%.*]] = xor <4 x i1> [[TMP41]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX2-NEXT:    [[TMP50:%.*]] = xor <4 x i1> [[TMP42]], <i1 true, i1 true, i1 true, i1 true>
 ; AVX2-NEXT:    [[TMP51:%.*]] = xor <4 x i1> [[TMP43]], <i1 true, i1 true, i1 true, i1 true>
-; AVX2-NEXT:    [[TMP52:%.*]] = and <4 x i1> [[TMP48]], [[TMP28]]
-; AVX2-NEXT:    [[TMP53:%.*]] = and <4 x i1> [[TMP49]], [[TMP29]]
-; AVX2-NEXT:    [[TMP54:%.*]] = and <4 x i1> [[TMP50]], [[TMP30]]
-; AVX2-NEXT:    [[TMP55:%.*]] = and <4 x i1> [[TMP51]], [[TMP31]]
+; AVX2-NEXT:    [[TMP52:%.*]] = select <4 x i1> [[TMP28]], <4 x i1> [[TMP48]], <4 x i1> zeroinitializer
+; AVX2-NEXT:    [[TMP53:%.*]] = select <4 x i1> [[TMP29]], <4 x i1> [[TMP49]], <4 x i1> zeroinitializer
+; AVX2-NEXT:    [[TMP54:%.*]] = select <4 x i1> [[TMP30]], <4 x i1> [[TMP50]], <4 x i1> zeroinitializer
+; AVX2-NEXT:    [[TMP55:%.*]] = select <4 x i1> [[TMP31]], <4 x i1> [[TMP51]], <4 x i1> zeroinitializer
 ; AVX2-NEXT:    [[TMP56:%.*]] = getelementptr inbounds double, double* [[TMP44]], i32 0
 ; AVX2-NEXT:    [[TMP57:%.*]] = bitcast double* [[TMP56]] to <4 x double>*
 ; AVX2-NEXT:    call void @llvm.masked.store.v4f64.p0v4f64(<4 x double> <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>, <4 x double>* [[TMP57]], i32 8, <4 x i1> [[TMP52]])
@@ -2707,10 +2707,10 @@ define void @foo8(double* noalias nocapture %out, i32 ()** noalias nocapture rea
 ; AVX512-NEXT:    [[TMP49:%.*]] = xor <8 x i1> [[TMP41]], <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>
 ; AVX512-NEXT:    [[TMP50:%.*]] = xor <8 x i1> [[TMP42]], <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>
 ; AVX512-NEXT:    [[TMP51:%.*]] = xor <8 x i1> [[TMP43]], <i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true, i1 true>
-; AVX512-NEXT:    [[TMP52:%.*]] = and <8 x i1> [[TMP48]], [[TMP28]]
-; AVX512-NEXT:    [[TMP53:%.*]] = and <8 x i1> [[TMP49]], [[TMP29]]
-; AVX512-NEXT:    [[TMP54:%.*]] = and <8 x i1> [[TMP50]], [[TMP30]]
-; AVX512-NEXT:    [[TMP55:%.*]] = and <8 x i1> [[TMP51]], [[TMP31]]
+; AVX512-NEXT:    [[TMP52:%.*]] = select <8 x i1> [[TMP28]], <8 x i1> [[TMP48]], <8 x i1> zeroinitializer
+; AVX512-NEXT:    [[TMP53:%.*]] = select <8 x i1> [[TMP29]], <8 x i1> [[TMP49]], <8 x i1> zeroinitializer
+; AVX512-NEXT:    [[TMP54:%.*]] = select <8 x i1> [[TMP30]], <8 x i1> [[TMP50]], <8 x i1> zeroinitializer
+; AVX512-NEXT:    [[TMP55:%.*]] = select <8 x i1> [[TMP31]], <8 x i1> [[TMP51]], <8 x i1> zeroinitializer
 ; AVX512-NEXT:    [[TMP56:%.*]] = getelementptr inbounds double, double* [[TMP44]], i32 0
 ; AVX512-NEXT:    [[TMP57:%.*]] = bitcast double* [[TMP56]] to <8 x double>*
 ; AVX512-NEXT:    call void @llvm.masked.store.v8f64.p0v8f64(<8 x double> <double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01, double 5.000000e-01>, <8 x double>* [[TMP57]], i32 8, <8 x i1> [[TMP52]])

llvm/test/Transforms/LoopVectorize/X86/x86-interleaved-accesses-masked-group.ll

@@ -408,7 +408,7 @@ define dso_local void @masked_strided1_optsize_unknown_tc(i8* noalias nocapture
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP0:%.*]] = icmp ugt <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT2]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP1:%.*]] = icmp ule <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP2:%.*]] = shl nuw nsw <8 x i32> [[VEC_IND]], <i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1>
-; DISABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = and <8 x i1> [[TMP0]], [[TMP1]]
+; DISABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = and <8 x i1> [[TMP1]], [[TMP0]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = extractelement <8 x i1> [[TMP3]], i32 0
 ; DISABLED_MASKED_STRIDED-NEXT:    br i1 [[TMP4]], label [[PRED_LOAD_IF:%.*]], label [[PRED_LOAD_CONTINUE:%.*]]
 ; DISABLED_MASKED_STRIDED:       pred.load.if:
@@ -520,7 +520,7 @@ define dso_local void @masked_strided1_optsize_unknown_tc(i8* noalias nocapture
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP1:%.*]] = icmp ule <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]]
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP2:%.*]] = shl nuw nsw i32 [[INDEX]], 1
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, i8* [[P:%.*]], i32 [[TMP2]]
-; ENABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = and <8 x i1> [[TMP0]], [[TMP1]]
+; ENABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = and <8 x i1> [[TMP1]], [[TMP0]]
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP5:%.*]] = bitcast i8* [[TMP3]] to <16 x i8>*
 ; ENABLED_MASKED_STRIDED-NEXT:    [[INTERLEAVED_MASK:%.*]] = shufflevector <8 x i1> [[TMP4]], <8 x i1> poison, <16 x i32> <i32 0, i32 0, i32 1, i32 1, i32 2, i32 2, i32 3, i32 3, i32 4, i32 4, i32 5, i32 5, i32 6, i32 6, i32 7, i32 7>
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP6:%.*]] = and <16 x i1> [[INTERLEAVED_MASK]], <i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false, i1 true, i1 false>
@@ -615,7 +615,7 @@ define dso_local void @masked_strided3_optsize_unknown_tc(i8* noalias nocapture
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP0:%.*]] = icmp ugt <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT2]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP1:%.*]] = icmp ule <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP2:%.*]] = mul nsw <8 x i32> [[VEC_IND]], <i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3, i32 3>
-; DISABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = and <8 x i1> [[TMP0]], [[TMP1]]
+; DISABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = and <8 x i1> [[TMP1]], [[TMP0]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = extractelement <8 x i1> [[TMP3]], i32 0
 ; DISABLED_MASKED_STRIDED-NEXT:    br i1 [[TMP4]], label [[PRED_LOAD_IF:%.*]], label [[PRED_LOAD_CONTINUE:%.*]]
 ; DISABLED_MASKED_STRIDED:       pred.load.if:
@@ -727,7 +727,7 @@ define dso_local void @masked_strided3_optsize_unknown_tc(i8* noalias nocapture
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP1:%.*]] = icmp ule <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]]
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP2:%.*]] = mul nsw i32 [[INDEX]], 3
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, i8* [[P:%.*]], i32 [[TMP2]]
-; ENABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = and <8 x i1> [[TMP0]], [[TMP1]]
+; ENABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = and <8 x i1> [[TMP1]], [[TMP0]]
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP5:%.*]] = bitcast i8* [[TMP3]] to <24 x i8>*
 ; ENABLED_MASKED_STRIDED-NEXT:    [[INTERLEAVED_MASK:%.*]] = shufflevector <8 x i1> [[TMP4]], <8 x i1> poison, <24 x i32> <i32 0, i32 0, i32 0, i32 1, i32 1, i32 1, i32 2, i32 2, i32 2, i32 3, i32 3, i32 3, i32 4, i32 4, i32 4, i32 5, i32 5, i32 5, i32 6, i32 6, i32 6, i32 7, i32 7, i32 7>
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP6:%.*]] = and <24 x i1> [[INTERLEAVED_MASK]], <i1 true, i1 false, i1 false, i1 true, i1 false, i1 false, i1 true, i1 false, i1 false, i1 true, i1 false, i1 false, i1 true, i1 false, i1 false, i1 true, i1 false, i1 false, i1 true, i1 false, i1 false, i1 true, i1 false, i1 false>
@@ -1535,7 +1535,7 @@ define dso_local void @masked_strided2_unknown_tc(i8* noalias nocapture readonly
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP0:%.*]] = icmp sgt <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT2]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP1:%.*]] = icmp ule <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP2:%.*]] = shl nuw nsw <8 x i32> [[VEC_IND]], <i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1, i32 1>
-; DISABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = and <8 x i1> [[TMP0]], [[TMP1]]
+; DISABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = and <8 x i1> [[TMP1]], [[TMP0]]
 ; DISABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = extractelement <8 x i1> [[TMP3]], i32 0
 ; DISABLED_MASKED_STRIDED-NEXT:    br i1 [[TMP4]], label [[PRED_LOAD_IF:%.*]], label [[PRED_LOAD_CONTINUE:%.*]]
 ; DISABLED_MASKED_STRIDED:       pred.load.if:
@@ -1871,7 +1871,7 @@ define dso_local void @masked_strided2_unknown_tc(i8* noalias nocapture readonly
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP1:%.*]] = icmp ule <8 x i32> [[VEC_IND]], [[BROADCAST_SPLAT]]
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP2:%.*]] = shl nuw nsw i32 [[INDEX]], 1
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, i8* [[P:%.*]], i32 [[TMP2]]
-; ENABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = and <8 x i1> [[TMP0]], [[TMP1]]
+; ENABLED_MASKED_STRIDED-NEXT:    [[TMP4:%.*]] = and <8 x i1> [[TMP1]], [[TMP0]]
 ; ENABLED_MASKED_STRIDED-NEXT:    [[TMP5:%.*]] = bitcast i8* [[TMP3]] to <16 x i8>*
 ; ENABLED_MASKED_STRIDED-NEXT:    [[INTERLEAVED_MASK:%.*]] = shufflevector <8 x i1> [[TMP4]], <8 x i1> poison, <16 x i32> <i32 0, i32 0, i32 1, i32 1, i32 2, i32 2, i32 3, i32 3, i32 4, i32 4, i32 5, i32 5, i32 6, i32 6, i32 7, i32 7>
 ; ENABLED_MASKED_STRIDED-NEXT:    [[WIDE_MASKED_VEC:%.*]] = call <16 x i8> @llvm.masked.load.v16i8.p0v16i8(<16 x i8>* [[TMP5]], i32 1, <16 x i1> [[INTERLEAVED_MASK]], <16 x i8> poison)

llvm/test/Transforms/LoopVectorize/if-conversion-nest.ll

@@ -39,7 +39,7 @@ define i32 @foo(i32* nocapture %A, i32* nocapture %B, i32 %n) {
 ; CHECK-NEXT:    [[TMP11:%.*]] = icmp sgt <4 x i32> [[WIDE_LOAD]], <i32 19, i32 19, i32 19, i32 19>
 ; CHECK-NEXT:    [[TMP12:%.*]] = icmp slt <4 x i32> [[WIDE_LOAD6]], <i32 4, i32 4, i32 4, i32 4>
 ; CHECK-NEXT:    [[TMP13:%.*]] = select <4 x i1> [[TMP12]], <4 x i32> <i32 4, i32 4, i32 4, i32 4>, <4 x i32> <i32 5, i32 5, i32 5, i32 5>
-; CHECK-NEXT:    [[TMP14:%.*]] = and <4 x i1> [[TMP11]], [[TMP10]]
+; CHECK-NEXT:    [[TMP14:%.*]] = and <4 x i1> [[TMP10]], [[TMP11]]
 ; CHECK-NEXT:    [[TMP15:%.*]] = xor <4 x i1> [[TMP11]], <i1 true, i1 true, i1 true, i1 true>
 ; CHECK-NEXT:    [[TMP16:%.*]] = and <4 x i1> [[TMP10]], [[TMP15]]
 ; CHECK-NEXT:    [[PREDPHI:%.*]] = select <4 x i1> [[TMP14]], <4 x i32> <i32 3, i32 3, i32 3, i32 3>, <4 x i32> <i32 9, i32 9, i32 9, i32 9>

llvm/test/Transforms/LoopVectorize/if-pred-non-void.ll

@@ -161,7 +161,7 @@ for.cond.cleanup:                                 ; preds = %if.end
 ; CHECK: %[[CMP1:.+]] = icmp slt <2 x i32> %[[VAL:.+]], <i32 100, i32 100>
 ; CHECK: %[[CMP2:.+]] = icmp sge <2 x i32> %[[VAL]], <i32 200, i32 200>
 ; CHECK: %[[NOT:.+]] = xor <2 x i1> %[[CMP1]], <i1 true, i1 true>
-; CHECK: %[[AND:.+]] = and <2 x i1> %[[CMP2]], %[[NOT]]
+; CHECK: %[[AND:.+]] = select <2 x i1> %[[NOT]], <2 x i1> %[[CMP2]], <2 x i1> zeroinitializer
 ; CHECK: %[[OR:.+]] = or <2 x i1> %[[AND]], %[[CMP1]]
 ; CHECK: %[[EXTRACT:.+]] = extractelement <2 x i1> %[[OR]], i32 0
 ; CHECK: br i1 %[[EXTRACT]], label %[[THEN:[a-zA-Z0-9.]+]], label %[[FI:[a-zA-Z0-9.]+]]

llvm/test/Transforms/LoopVectorize/if-reduction.ll

@@ -610,9 +610,9 @@ for.end:                                          ; preds = %for.body, %entry
 ; CHECK-DAG: %[[M1:.*]] = fmul fast <4 x float> %[[V0]], <float 3.000000e+00,
 ; CHECK-DAG: %[[M2:.*]] = fmul fast <4 x float> %[[V0]], <float 2.000000e+00,
 ; CHECK: %[[C11:.*]] = xor <4 x i1> %[[C1]], <i1 true,
-; CHECK-DAG: %[[C12:.*]] = and <4 x i1> %[[C2]], %[[C11]]
+; CHECK-DAG: %[[C12:.*]] = select <4 x i1> %[[C11]], <4 x i1> %[[C2]], <4 x i1> zeroinitializer
 ; CHECK-DAG: %[[C21:.*]] = xor <4 x i1> %[[C2]], <i1 true,
-; CHECK: %[[C22:.*]] = and <4 x i1> %[[C21]], %[[C11]]
+; CHECK: %[[C22:.*]] = select <4 x i1> %[[C11]], <4 x i1> %[[C21]], <4 x i1> zeroinitializer
 ; CHECK: %[[S1:.*]] = select <4 x i1> %[[C22]], <4 x float> %[[M1]], <4 x float> %[[M2]]
 ; CHECK: %[[S2:.*]] = select <4 x i1> %[[C1]], <4 x float> %[[V0]], <4 x float> %[[S1]]
 ; CHECK: fadd fast <4 x float> %[[S2]],
@@ -678,9 +678,9 @@ for.end:                                          ; preds = %for.inc, %entry
 ; CHECK-DAG: %[[SUB:.*]] = fsub fast <4 x float>
 ; CHECK-DAG: %[[ADD:.*]] = fadd fast <4 x float>
 ; CHECK: %[[C11:.*]] = xor <4 x i1> %[[C1]], <i1 true,
-; CHECK-DAG: %[[C12:.*]] = and <4 x i1> %[[C2]], %[[C11]]
+; CHECK-DAG: %[[C12:.*]] = select <4 x i1> %[[C11]], <4 x i1> %[[C2]], <4 x i1> zeroinitializer
 ; CHECK-DAG: %[[C21:.*]] = xor <4 x i1> %[[C2]], <i1 true,
-; CHECK: %[[C22:.*]] = and <4 x i1> %[[C21]], %[[C11]]
+; CHECK: %[[C22:.*]] = select <4 x i1> %[[C11]], <4 x i1> %[[C21]], <4 x i1> zeroinitializer
 ; CHECK: %[[S1:.*]] = select <4 x i1> %[[C12]], <4 x float> %[[SUB]], <4 x float> %[[ADD]]
 ; CHECK: %[[S2:.*]] = select <4 x i1> %[[C22]], {{.*}} <4 x float> %[[S1]]
 define float @fcmp_fadd_fsub(float* nocapture readonly %a, i32 %n) nounwind readonly {