[PatternMatch] Add m_SExtOrSelf(), m_ZExtOrSExtOrSelf() matchers + unittests

m_SExtOrSelf() is for consistency.

m_ZExtOrSExtOrSelf() is motivated by the D68103/r373106 :
sometimes it is useful to look past any extensions of the shift amount,
and m_ZExtOrSExtOrSelf() may be exactly the tool to do that.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373128 91177308-0d34-0410-b5e6-96231b3b80d8

include/llvm/IR/PatternMatch.h

@@ -1319,6 +1319,12 @@ m_ZExtOrSelf(const OpTy &Op) {
   return m_CombineOr(m_ZExt(Op), Op);
 }
 
+template <typename OpTy>
+inline match_combine_or<CastClass_match<OpTy, Instruction::SExt>, OpTy>
+m_SExtOrSelf(const OpTy &Op) {
+  return m_CombineOr(m_SExt(Op), Op);
+}
+
 template <typename OpTy>
 inline match_combine_or<CastClass_match<OpTy, Instruction::ZExt>,
                         CastClass_match<OpTy, Instruction::SExt>>
@@ -1326,6 +1332,15 @@ m_ZExtOrSExt(const OpTy &Op) {
   return m_CombineOr(m_ZExt(Op), m_SExt(Op));
 }
 
+template <typename OpTy>
+inline match_combine_or<
+    match_combine_or<CastClass_match<OpTy, Instruction::ZExt>,
+                     CastClass_match<OpTy, Instruction::SExt>>,
+    OpTy>
+m_ZExtOrSExtOrSelf(const OpTy &Op) {
+  return m_CombineOr(m_ZExtOrSExt(Op), Op);
+}
+
 /// Matches UIToFP.
 template <typename OpTy>
 inline CastClass_match<OpTy, Instruction::UIToFP> m_UIToFP(const OpTy &Op) {

unittests/IR/PatternMatch.cpp

@@ -471,6 +471,42 @@ TEST_F(PatternMatchTest, Unless) {
   EXPECT_FALSE(m_Unless(m_c_Add(m_Zero(), m_One())).match(X));
 }
 
+TEST_F(PatternMatchTest, ZExtSExtSelf) {
+  LLVMContext &Ctx = IRB.getContext();
+
+  Value *One32 = IRB.getInt32(1);
+  Value *One64Z = IRB.CreateZExt(One32, IntegerType::getInt64Ty(Ctx));
+  Value *One64S = IRB.CreateSExt(One32, IntegerType::getInt64Ty(Ctx));
+
+  EXPECT_TRUE(m_One().match(One32));
+  EXPECT_FALSE(m_One().match(One64Z));
+  EXPECT_FALSE(m_One().match(One64S));
+
+  EXPECT_FALSE(m_ZExt(m_One()).match(One32));
+  EXPECT_TRUE(m_ZExt(m_One()).match(One64Z));
+  EXPECT_FALSE(m_ZExt(m_One()).match(One64S));
+
+  EXPECT_FALSE(m_SExt(m_One()).match(One32));
+  EXPECT_FALSE(m_SExt(m_One()).match(One64Z));
+  EXPECT_TRUE(m_SExt(m_One()).match(One64S));
+
+  EXPECT_TRUE(m_ZExtOrSelf(m_One()).match(One32));
+  EXPECT_TRUE(m_ZExtOrSelf(m_One()).match(One64Z));
+  EXPECT_FALSE(m_ZExtOrSelf(m_One()).match(One64S));
+
+  EXPECT_TRUE(m_SExtOrSelf(m_One()).match(One32));
+  EXPECT_FALSE(m_SExtOrSelf(m_One()).match(One64Z));
+  EXPECT_TRUE(m_SExtOrSelf(m_One()).match(One64S));
+
+  EXPECT_FALSE(m_ZExtOrSExt(m_One()).match(One32));
+  EXPECT_TRUE(m_ZExtOrSExt(m_One()).match(One64Z));
+  EXPECT_TRUE(m_ZExtOrSExt(m_One()).match(One64S));
+
+  EXPECT_TRUE(m_ZExtOrSExtOrSelf(m_One()).match(One32));
+  EXPECT_TRUE(m_ZExtOrSExtOrSelf(m_One()).match(One64Z));
+  EXPECT_TRUE(m_ZExtOrSExtOrSelf(m_One()).match(One64S));
+}
+
 TEST_F(PatternMatchTest, Power2) {
   Value *C128 = IRB.getInt32(128);
   Value *CNeg128 = ConstantExpr::getNeg(cast<Constant>(C128));