[IR][Patternmatch] Add m_SpecificInt_ULT() predicate

Summary:
Match an integer or vector with every element unsigned less than the
Threshold. For vectors, this includes constants with undefined elements.

FIXME: is it worth generalizing this to simply take ICmpInst::Predicate?

Reviewers: craig.topper, spatel, nikic

Reviewed By: spatel

Subscribers: llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D63811

llvm-svn: 364711

1 files changed, 21 insertions, 0 deletions

diff --git a/llvm/unittests/IR/PatternMatch.cpp b/llvm/unittests/IR/PatternMatch.cpp
index de47975e7c6..8ea7a68b27c 100644
--- a/llvm/unittests/IR/PatternMatch.cpp
+++ b/llvm/unittests/IR/PatternMatch.cpp
@@ -64,6 +64,27 @@ TEST_F(PatternMatchTest, OneUse) {
   EXPECT_FALSE(m_OneUse(m_Value()).match(Leaf));
 }
 
+TEST_F(PatternMatchTest, SpecificIntULT) {
+  Type *IntTy = IRB.getInt32Ty();
+  unsigned BitWidth = IntTy->getScalarSizeInBits();
+
+  Value *Zero = ConstantInt::get(IntTy, 0);
+  Value *One = ConstantInt::get(IntTy, 1);
+  Value *NegOne = ConstantInt::get(IntTy, -1);
+
+  EXPECT_FALSE(m_SpecificInt_ULT(APInt(BitWidth, 0)).match(Zero));
+  EXPECT_FALSE(m_SpecificInt_ULT(APInt(BitWidth, 0)).match(One));
+  EXPECT_FALSE(m_SpecificInt_ULT(APInt(BitWidth, 0)).match(NegOne));
+
+  EXPECT_TRUE(m_SpecificInt_ULT(APInt(BitWidth, 1)).match(Zero));
+  EXPECT_FALSE(m_SpecificInt_ULT(APInt(BitWidth, 1)).match(One));
+  EXPECT_FALSE(m_SpecificInt_ULT(APInt(BitWidth, 1)).match(NegOne));
+
+  EXPECT_TRUE(m_SpecificInt_ULT(APInt(BitWidth, -1)).match(Zero));
+  EXPECT_TRUE(m_SpecificInt_ULT(APInt(BitWidth, -1)).match(One));
+  EXPECT_FALSE(m_SpecificInt_ULT(APInt(BitWidth, -1)).match(NegOne));
+}
+
 TEST_F(PatternMatchTest, CommutativeDeferredValue) {
   Value *X = IRB.getInt32(1);
   Value *Y = IRB.getInt32(2);