[llvm-branch-commits] [llvm] 9b01896 - [IR] Support scalable vectors in ShuffleVectorInst::increasesLength

[Cullen Rhodes via llvm-branch-commits]

Author: Cullen Rhodes
Date: 2020-12-07T10:42:48Z
New Revision: 9b0189655500c30c4ccb0fb5f3ce14a2ac9c6682

URL: https://github.com/llvm/llvm-project/commit/9b0189655500c30c4ccb0fb5f3ce14a2ac9c6682
DIFF: https://github.com/llvm/llvm-project/commit/9b0189655500c30c4ccb0fb5f3ce14a2ac9c6682.diff

LOG: [IR] Support scalable vectors in ShuffleVectorInst::increasesLength

Since the length of the llvm::SmallVector shufflemask is related to the
minimum number of elements in a scalable vector, it is fine to just get
the Min field of the ElementCount. This is already done for the similar
function changesLength, tests have been added for both.

Reviewed By: sdesmalen

Differential Revision: https://reviews.llvm.org/D92472

Added: 
    

Modified: 
    llvm/include/llvm/IR/Instructions.h
    llvm/unittests/IR/InstructionsTest.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/IR/Instructions.h b/llvm/include/llvm/IR/Instructions.h
index 4b08de66e398..00ecc2aa7f37 100644
--- a/llvm/include/llvm/IR/Instructions.h
+++ b/llvm/include/llvm/IR/Instructions.h
@@ -2081,8 +2081,9 @@ class ShuffleVectorInst : public Instruction {
   /// elements than its source vectors.
   /// Example: shufflevector <2 x n> A, <2 x n> B, <1,2,3>
   bool increasesLength() const {
-    unsigned NumSourceElts =
-        cast<FixedVectorType>(Op<0>()->getType())->getNumElements();
+    unsigned NumSourceElts = cast<VectorType>(Op<0>()->getType())
+                                 ->getElementCount()
+                                 .getKnownMinValue();
     unsigned NumMaskElts = ShuffleMask.size();
     return NumSourceElts < NumMaskElts;
   }

diff  --git a/llvm/unittests/IR/InstructionsTest.cpp b/llvm/unittests/IR/InstructionsTest.cpp
index f98ef4b52ccd..09260d347840 100644
--- a/llvm/unittests/IR/InstructionsTest.cpp
+++ b/llvm/unittests/IR/InstructionsTest.cpp
@@ -1083,7 +1083,19 @@ TEST(InstructionsTest, ShuffleMaskQueries) {
                             Constant::getNullValue(VScaleV4Int32Ty));
   int Index = 0;
   EXPECT_FALSE(Id13->isExtractSubvectorMask(Index));
+  EXPECT_FALSE(Id13->changesLength());
+  EXPECT_FALSE(Id13->increasesLength());
   delete Id13;
+
+  // Result has twice as many operands.
+  Type *VScaleV2Int32Ty = ScalableVectorType::get(Int32Ty, 2);
+  ShuffleVectorInst *Id14 =
+      new ShuffleVectorInst(Constant::getAllOnesValue(VScaleV2Int32Ty),
+                            UndefValue::get(VScaleV2Int32Ty),
+                            Constant::getNullValue(VScaleV4Int32Ty));
+  EXPECT_TRUE(Id14->changesLength());
+  EXPECT_TRUE(Id14->increasesLength());
+  delete Id14;
 }
 
 TEST(InstructionsTest, GetSplat) {