[PATCH] D92475: [IR] Bail out for scalable vectors in ShuffleVectorInst::isConcat

[Cullen Rhodes via Phabricator via llvm-commits]

c-rhodes created this revision.
c-rhodes added reviewers: sdesmalen, ctetreau, craig.topper.
Herald added subscribers: dexonsmith, hiraditya.
Herald added a project: LLVM.
c-rhodes requested review of this revision.

Shuffle mask for concat can't be expressed for scalable vectors, so we
should bail out. A test has been added that previously crashed, also
tested isIdentityWithPadding and isIdentityWithExtract where we already
bail out.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D92475

Files:
  llvm/lib/IR/Instructions.cpp
  llvm/unittests/IR/InstructionsTest.cpp


Index: llvm/unittests/IR/InstructionsTest.cpp
===================================================================
--- llvm/unittests/IR/InstructionsTest.cpp
+++ llvm/unittests/IR/InstructionsTest.cpp
@@ -1096,6 +1096,17 @@
   EXPECT_TRUE(Id14->changesLength());
   EXPECT_TRUE(Id14->increasesLength());
   delete Id14;
+
+  // Not possible to express these masks for scalable vectors, make sure we
+  // don't crash.
+  ShuffleVectorInst *Id15 =
+      new ShuffleVectorInst(Constant::getAllOnesValue(VScaleV2Int32Ty),
+                            Constant::getNullValue(VScaleV2Int32Ty),
+                            Constant::getNullValue(VScaleV2Int32Ty));
+  EXPECT_FALSE(Id15->isIdentityWithPadding());
+  EXPECT_FALSE(Id15->isIdentityWithExtract());
+  EXPECT_FALSE(Id15->isConcat());
+  delete Id15;
 }
 
 TEST(InstructionsTest, GetSplat) {
Index: llvm/lib/IR/Instructions.cpp
===================================================================
--- llvm/lib/IR/Instructions.cpp
+++ llvm/lib/IR/Instructions.cpp
@@ -2274,6 +2274,11 @@
       isa<UndefValue>(Op<2>()))
     return false;
 
+  // FIXME: Not currently possible to express a shuffle mask for a scalable
+  // vector for this case.
+  if (isa<ScalableVectorType>(getType()))
+    return false;
+
   int NumOpElts = cast<FixedVectorType>(Op<0>()->getType())->getNumElements();
   int NumMaskElts = cast<FixedVectorType>(getType())->getNumElements();
   if (NumMaskElts != NumOpElts * 2)


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D92475.308930.patch
Type: text/x-patch
Size: 1454 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20201202/5e211327/attachment.bin>