[PatternMatch] Make m_Br more flexible, add matchers for BB values.

Currently m_Br only takes references to BasicBlock*, which limits its
flexibility. For example, you have to declare a variable, even if you
ignore the result or you have to have additional checks to make sure the
matched BB matches an expected one.

This patch adds m_BasicBlock and m_SpecificBB matchers, which can be
used like the existing matchers for constants or values.

I also had a look at the existing uses and updated a few. IMO it makes
the code a bit more explicit.

Reviewers: spatel, craig.topper, RKSimon, majnemer, lebedev.ri

Reviewed By: lebedev.ri

Differential Revision: https://reviews.llvm.org/D68013

llvm-svn: 372885

1 files changed, 28 insertions, 0 deletions

diff --git a/llvm/unittests/IR/PatternMatch.cpp b/llvm/unittests/IR/PatternMatch.cpp
index fe8c518fa82..d52d4fe980f 100644
--- a/llvm/unittests/IR/PatternMatch.cpp
+++ b/llvm/unittests/IR/PatternMatch.cpp
@@ -1045,6 +1045,34 @@ TEST_F(PatternMatchTest, FloatingPointFNeg) {
   EXPECT_FALSE(match(V3, m_FNeg(m_Value(Match))));
 }
 
+TEST_F(PatternMatchTest, CondBranchTest) {
+  BasicBlock *TrueBB = BasicBlock::Create(Ctx, "TrueBB", F);
+  BasicBlock *FalseBB = BasicBlock::Create(Ctx, "FalseBB", F);
+  Value *Br1 = IRB.CreateCondBr(IRB.getTrue(), TrueBB, FalseBB);
+
+  EXPECT_TRUE(match(Br1, m_Br(m_Value(), m_BasicBlock(), m_BasicBlock())));
+
+  BasicBlock *A, *B;
+  EXPECT_TRUE(match(Br1, m_Br(m_Value(), m_BasicBlock(A), m_BasicBlock(B))));
+  EXPECT_EQ(TrueBB, A);
+  EXPECT_EQ(FalseBB, B);
+
+  EXPECT_FALSE(
+      match(Br1, m_Br(m_Value(), m_SpecificBB(FalseBB), m_BasicBlock())));
+  EXPECT_FALSE(
+      match(Br1, m_Br(m_Value(), m_BasicBlock(), m_SpecificBB(TrueBB))));
+  EXPECT_FALSE(
+      match(Br1, m_Br(m_Value(), m_SpecificBB(FalseBB), m_BasicBlock(TrueBB))));
+  EXPECT_TRUE(
+      match(Br1, m_Br(m_Value(), m_SpecificBB(TrueBB), m_BasicBlock(FalseBB))));
+
+  // Check we can use m_Deferred with branches.
+  EXPECT_FALSE(match(Br1, m_Br(m_Value(), m_BasicBlock(A), m_Deferred(A))));
+  Value *Br2 = IRB.CreateCondBr(IRB.getTrue(), TrueBB, TrueBB);
+  A = nullptr;
+  EXPECT_TRUE(match(Br2, m_Br(m_Value(), m_BasicBlock(A), m_Deferred(A))));
+}
+
 template <typename T> struct MutableConstTest : PatternMatchTest { };
 
 typedef ::testing::Types<std::tuple<Value*, Instruction*>,