[GISel][NFCish]: Add pattern matchers for G_BITCAST/PTRTOINT/INTTOPTR

[aditya_nandakumar]

Summary

Adds pattern matchers for the above along with unit tests for the same.

[dsanders]

LGTM without the 'NFCish' in the subject line. This is a functional change to support these matchers.

[aditya_nandakumar]

Committed in r325542. Thanks for the review Daniel.

include/llvm/CodeGen/GlobalISel/MIPatternMatch.h

 }
 
 template <typename SrcTy>
 inline UnaryOp_match<SrcTy, TargetOpcode::G_TRUNC> m_GTrunc(const SrcTy &Src) {
   return UnaryOp_match<SrcTy, TargetOpcode::G_TRUNC>(Src);
 }
 
 template <typename SrcTy>
+inline UnaryOp_match<SrcTy, TargetOpcode::G_BITCAST>
+m_GBitcast(const SrcTy &Src) {
+  return UnaryOp_match<SrcTy, TargetOpcode::G_BITCAST>(Src);
+}
+
+template <typename SrcTy>
+inline UnaryOp_match<SrcTy, TargetOpcode::G_PTRTOINT>
+m_GPtrToInt(const SrcTy &Src) {
+  return UnaryOp_match<SrcTy, TargetOpcode::G_PTRTOINT>(Src);
+}
+
+template <typename SrcTy>
+inline UnaryOp_match<SrcTy, TargetOpcode::G_INTTOPTR>
+m_GIntToPtr(const SrcTy &Src) {
+  return UnaryOp_match<SrcTy, TargetOpcode::G_INTTOPTR>(Src);
+}
+
+template <typename SrcTy>
 inline UnaryOp_match<SrcTy, TargetOpcode::G_FPTRUNC>
 m_GFPTrunc(const SrcTy &Src) {
   return UnaryOp_match<SrcTy, TargetOpcode::G_FPTRUNC>(Src);
 }
 
 template <typename SrcTy>
 inline UnaryOp_match<SrcTy, TargetOpcode::COPY> m_Copy(SrcTy &&Src) {
   return UnaryOp_match<SrcTy, TargetOpcode::COPY>(std::forward<SrcTy>(Src));

unittests/CodeGen/GlobalISel/PatternMatchTest.cpp

ASSERT_FALSE(mi_match(MIBAdd->getOperand(0).getReg(), MRI,
                         m_GAdd(m_SpecificType(s32), m_Reg())));
   ASSERT_TRUE(mi_match(MIBAdd->getOperand(0).getReg(), MRI,
                        m_GAdd(m_SpecificType(s64), m_Reg())));
 
   // Try to match the destination type of a bitcast.
   LLT v2s32 = LLT::vector(2, 32);
   auto MIBCast = B.buildCast(v2s32, Copies[0]);
   ASSERT_TRUE(
+      mi_match(MIBCast->getOperand(0).getReg(), MRI, m_GBitcast(m_Reg())));
+  ASSERT_TRUE(
       mi_match(MIBCast->getOperand(0).getReg(), MRI, m_SpecificType(v2s32)));
   ASSERT_TRUE(
       mi_match(MIBCast->getOperand(1).getReg(), MRI, m_SpecificType(s64)));
+
+  // Build a PTRToInt and INTTOPTR and match and test them.
+  LLT PtrTy = LLT::pointer(0, 64);
+  auto MIBIntToPtr = B.buildCast(PtrTy, Copies[0]);
+  auto MIBPtrToInt = B.buildCast(s64, MIBIntToPtr);
+  unsigned Src0;
+
+  // match the ptrtoint(inttoptr reg)
+  bool match = mi_match(MIBPtrToInt->getOperand(0).getReg(), MRI,
+                        m_GPtrToInt(m_GIntToPtr(m_Reg(Src0))));
+  ASSERT_TRUE(match);
+  ASSERT_EQ(Src0, Copies[0]);
 }
 
 TEST(PatternMatchInstr, MatchCombinators) {
   LLVMContext Context;
   std::unique_ptr<TargetMachine> TM = createTargetMachine();
   if (!TM)
     return;
   auto ModuleMMIPair = createDummyModule(Context, *TM, "");