[llvm] r343270 - [ScalarizeMaskedMemIntrin] Handle the case where the mask is an all zero vector.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Thu Sep 27 14:28:46 2018
New Revision: 343270

URL: http://llvm.org/viewvc/llvm-project?rev=343270&view=rev
Log:
[ScalarizeMaskedMemIntrin] Handle the case where the mask is an all zero vector.

This shouldn't really happen in practice I hope, but we tried to handle other constant cases. We missed this one because we checked for ConstantVector without realizing that zero becomes ConstantAggregateZero instead.

So instead just check for Constant and use getAggregateElement which will do the dirty work for us.

Modified:
    llvm/trunk/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp
    llvm/trunk/test/Transforms/ScalarizeMaskedMemIntrin/X86/expand-masked-load.ll

Modified: llvm/trunk/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp?rev=343270&r1=343269&r2=343270&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp (original)
+++ llvm/trunk/lib/CodeGen/ScalarizeMaskedMemIntrin.cpp Thu Sep 27 14:28:46 2018
@@ -151,9 +151,9 @@ static void scalarizeMaskedLoad(CallInst
   // The result vector
   Value *VResult = UndefVal;
 
-  if (isa<ConstantVector>(Mask)) {
+  if (isa<Constant>(Mask)) {
     for (unsigned Idx = 0; Idx < VectorWidth; ++Idx) {
-      if (cast<ConstantVector>(Mask)->getOperand(Idx)->isNullValue())
+      if (cast<Constant>(Mask)->getAggregateElement(Idx)->isNullValue())
         continue;
       Value *Gep =
           Builder.CreateInBoundsGEP(EltTy, FirstEltPtr, Builder.getInt32(Idx));
@@ -280,9 +280,9 @@ static void scalarizeMaskedStore(CallIns
   Value *FirstEltPtr = Builder.CreateBitCast(Ptr, NewPtrType);
   unsigned VectorWidth = VecType->getNumElements();
 
-  if (isa<ConstantVector>(Mask)) {
+  if (isa<Constant>(Mask)) {
     for (unsigned Idx = 0; Idx < VectorWidth; ++Idx) {
-      if (cast<ConstantVector>(Mask)->getOperand(Idx)->isNullValue())
+      if (cast<Constant>(Mask)->getAggregateElement(Idx)->isNullValue())
         continue;
       Value *OneElt = Builder.CreateExtractElement(Src, Builder.getInt32(Idx));
       Value *Gep =
@@ -385,9 +385,9 @@ static void scalarizeMaskedGather(CallIn
   unsigned VectorWidth = VecType->getNumElements();
 
   // Shorten the way if the mask is a vector of constants.
-  if (isa<ConstantVector>(Mask)) {
+  if (isa<Constant>(Mask)) {
     for (unsigned Idx = 0; Idx < VectorWidth; ++Idx) {
-      if (cast<ConstantVector>(Mask)->getOperand(Idx)->isNullValue())
+      if (cast<Constant>(Mask)->getAggregateElement(Idx)->isNullValue())
         continue;
       Value *Ptr = Builder.CreateExtractElement(Ptrs, Builder.getInt32(Idx),
                                                 "Ptr" + Twine(Idx));
@@ -504,9 +504,9 @@ static void scalarizeMaskedScatter(CallI
   unsigned VectorWidth = Src->getType()->getVectorNumElements();
 
   // Shorten the way if the mask is a vector of constants.
-  if (isa<ConstantVector>(Mask)) {
+  if (isa<Constant>(Mask)) {
     for (unsigned Idx = 0; Idx < VectorWidth; ++Idx) {
-      if (cast<ConstantVector>(Mask)->getOperand(Idx)->isNullValue())
+      if (cast<ConstantVector>(Mask)->getAggregateElement(Idx)->isNullValue())
         continue;
       Value *OneElt = Builder.CreateExtractElement(Src, Builder.getInt32(Idx),
                                                    "Elt" + Twine(Idx));

Modified: llvm/trunk/test/Transforms/ScalarizeMaskedMemIntrin/X86/expand-masked-load.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ScalarizeMaskedMemIntrin/X86/expand-masked-load.ll?rev=343270&r1=343269&r2=343270&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ScalarizeMaskedMemIntrin/X86/expand-masked-load.ll (original)
+++ llvm/trunk/test/Transforms/ScalarizeMaskedMemIntrin/X86/expand-masked-load.ll Thu Sep 27 14:28:46 2018
@@ -41,24 +41,8 @@ define <2 x i64> @scalarize_v2i64_ones_m
 define <2 x i64> @scalarize_v2i64_zero_mask(<2 x i64>* %p, <2 x i64> %passthru) {
 ; CHECK-LABEL: @scalarize_v2i64_zero_mask(
 ; CHECK-NEXT:    [[TMP1:%.*]] = bitcast <2 x i64>* [[P:%.*]] to i64*
-; CHECK-NEXT:    br i1 false, label [[COND_LOAD:%.*]], label [[ELSE:%.*]]
-; CHECK:       cond.load:
-; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds i64, i64* [[TMP1]], i32 0
-; CHECK-NEXT:    [[TMP3:%.*]] = load i64, i64* [[TMP2]], align 8
-; CHECK-NEXT:    [[TMP4:%.*]] = insertelement <2 x i64> undef, i64 [[TMP3]], i32 0
-; CHECK-NEXT:    br label [[ELSE]]
-; CHECK:       else:
-; CHECK-NEXT:    [[RES_PHI_ELSE:%.*]] = phi <2 x i64> [ [[TMP4]], [[COND_LOAD]] ], [ undef, [[TMP0:%.*]] ]
-; CHECK-NEXT:    br i1 false, label [[COND_LOAD1:%.*]], label [[ELSE2:%.*]]
-; CHECK:       cond.load1:
-; CHECK-NEXT:    [[TMP5:%.*]] = getelementptr inbounds i64, i64* [[TMP1]], i32 1
-; CHECK-NEXT:    [[TMP6:%.*]] = load i64, i64* [[TMP5]], align 8
-; CHECK-NEXT:    [[TMP7:%.*]] = insertelement <2 x i64> [[RES_PHI_ELSE]], i64 [[TMP6]], i32 1
-; CHECK-NEXT:    br label [[ELSE2]]
-; CHECK:       else2:
-; CHECK-NEXT:    [[RES_PHI_SELECT:%.*]] = phi <2 x i64> [ [[TMP7]], [[COND_LOAD1]] ], [ [[RES_PHI_ELSE]], [[ELSE]] ]
-; CHECK-NEXT:    [[TMP8:%.*]] = select <2 x i1> zeroinitializer, <2 x i64> [[RES_PHI_SELECT]], <2 x i64> [[PASSTHRU:%.*]]
-; CHECK-NEXT:    ret <2 x i64> [[TMP8]]
+; CHECK-NEXT:    [[TMP2:%.*]] = select <2 x i1> zeroinitializer, <2 x i64> undef, <2 x i64> [[PASSTHRU:%.*]]
+; CHECK-NEXT:    ret <2 x i64> [[TMP2]]
 ;
   %ret = call <2 x i64> @llvm.masked.load.v2i64.p0v2i64(<2 x i64>* %p, i32 8, <2 x i1> <i1 false, i1 false>, <2 x i64> %passthru)
   ret <2 x i64> %ret