[MIPatternMatch] Add matcher for G_PTR_ADD

Add a matcher which recognizes G_PTR_ADD and add a test.

Differential Revision: https://reviews.llvm.org/D94348

Author: Jessica Paquette

llvm/include/llvm/CodeGen/GlobalISel/MIPatternMatch.h

@@ -220,6 +220,12 @@ m_GAdd(const LHS &L, const RHS &R) {
   return BinaryOp_match<LHS, RHS, TargetOpcode::G_ADD, true>(L, R);
 }
 
+template <typename LHS, typename RHS>
+inline BinaryOp_match<LHS, RHS, TargetOpcode::G_PTR_ADD, true>
+m_GPtrAdd(const LHS &L, const RHS &R) {
+  return BinaryOp_match<LHS, RHS, TargetOpcode::G_PTR_ADD, true>(L, R);
+}
+
 template <typename LHS, typename RHS>
 inline BinaryOp_match<LHS, RHS, TargetOpcode::G_SUB> m_GSub(const LHS &L,
                                                             const RHS &R) {

llvm/unittests/CodeGen/GlobalISel/PatternMatchTest.cpp

@@ -47,6 +47,7 @@ TEST_F(AArch64GISelMITest, MatchBinaryOp) {
     return;
   LLT s32 = LLT::scalar(32);
   LLT s64 = LLT::scalar(64);
+  LLT p0 = LLT::pointer(0, 64);
   auto MIBAdd = B.buildAdd(s64, Copies[0], Copies[1]);
   // Test case for no bind.
   bool match =
@@ -145,6 +146,13 @@ TEST_F(AArch64GISelMITest, MatchBinaryOp) {
   EXPECT_TRUE(match);
   EXPECT_EQ(Src0, Copies[0]);
   EXPECT_EQ(Src1, TruncCopy1.getReg(0));
+
+  // Build a G_PTR_ADD and check that we can match it.
+  auto PtrAdd = B.buildPtrAdd(p0, {B.buildUndef(p0)}, Copies[0]);
+  match = mi_match(PtrAdd.getReg(0), *MRI, m_GPtrAdd(m_Reg(Src0), m_Reg(Src1)));
+  EXPECT_TRUE(match);
+  EXPECT_EQ(Src0, PtrAdd->getOperand(1).getReg());
+  EXPECT_EQ(Src1, Copies[0]);
 }
 
 TEST_F(AArch64GISelMITest, MatchICmp) {