[llvm] 88de933 - [ConstantFold][SVE] Fix constand fold for vector call.

[Huihui Zhang via llvm-commits]

Author: Huihui Zhang
Date: 2020-02-11T14:06:15-08:00
New Revision: 88de9338f26c3c75001c17a5c4b71736e18fa0b6

URL: https://github.com/llvm/llvm-project/commit/88de9338f26c3c75001c17a5c4b71736e18fa0b6
DIFF: https://github.com/llvm/llvm-project/commit/88de9338f26c3c75001c17a5c4b71736e18fa0b6.diff

LOG: [ConstantFold][SVE] Fix constand fold for vector call.

Summary:
Do not iterate on scalable vectors.

Reviewers: sdesmalen, efriedma, apazos, huntergr, willlovett

Reviewed By: sdesmalen

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74419

Added: 
    

Modified: 
    llvm/lib/Analysis/ConstantFolding.cpp
    llvm/test/Analysis/ConstantFolding/vscale.ll

Removed: 
    


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diff  --git a/llvm/lib/Analysis/ConstantFolding.cpp b/llvm/lib/Analysis/ConstantFolding.cpp
index 280a13ff1153..0ebc6a5919e8 100644
--- a/llvm/lib/Analysis/ConstantFolding.cpp
+++ b/llvm/lib/Analysis/ConstantFolding.cpp
@@ -2400,6 +2400,11 @@ static Constant *ConstantFoldVectorCall(StringRef Name,
   SmallVector<Constant *, 4> Lane(Operands.size());
   Type *Ty = VTy->getElementType();
 
+  // Do not iterate on scalable vector. The number of elements is unknown at
+  // compile-time.
+  if (VTy->getVectorIsScalable())
+    return nullptr;
+
   if (IntrinsicID == Intrinsic::masked_load) {
     auto *SrcPtr = Operands[0];
     auto *Mask = Operands[2];

diff  --git a/llvm/test/Analysis/ConstantFolding/vscale.ll b/llvm/test/Analysis/ConstantFolding/vscale.ll
index 2491308910df..3a3d6a16c7d6 100644
--- a/llvm/test/Analysis/ConstantFolding/vscale.ll
+++ b/llvm/test/Analysis/ConstantFolding/vscale.ll
@@ -210,3 +210,14 @@ define <vscale x 4 x i32> @select() {
   %r = select <vscale x 4 x i1> undef, <vscale x 4 x i32> zeroinitializer, <vscale x 4 x i32> undef
   ret <vscale x 4 x i32> %r
 }
+
+declare <vscale x 16 x i8> @llvm.sadd.sat.nxv16i8(<vscale x 16 x i8>, <vscale x 16 x i8>)
+
+define <vscale x 16 x i8> @call() {
+; CHECK-LABEL: @call(
+; CHECK-NEXT:    [[R:%.*]] = call <vscale x 16 x i8> @llvm.sadd.sat.nxv16i8(<vscale x 16 x i8> undef, <vscale x 16 x i8> undef)
+; CHECK-NEXT:    ret <vscale x 16 x i8> [[R]]
+;
+  %r =  call <vscale x 16 x i8> @llvm.sadd.sat.nxv16i8(<vscale x 16 x i8> undef, <vscale x 16 x i8> undef)
+  ret <vscale x 16 x i8> %r
+}