GlobalISel: add a G_PHI instruction to give phis a type.

They're another source of generic vregs, which are going to need a type on the
definition when we remove the register width from MachineRegisterInfo.

llvm-svn: 280412

3 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index a27d53941a4..f0ac16712a5 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -405,7 +405,7 @@ bool IRTranslator::translateStaticAlloca(const AllocaInst &AI) {
 
 bool IRTranslator::translatePHI(const User &U) {
   const PHINode &PI = cast<PHINode>(U);
-  MachineInstrBuilder MIB = MIRBuilder.buildInstr(TargetOpcode::PHI);
+  auto MIB = MIRBuilder.buildInstr(TargetOpcode::G_PHI, LLT{*U.getType()});
   MIB.addDef(getOrCreateVReg(PI));
 
   PendingPHIs.emplace_back(&PI, MIB.getInstr());
diff --git a/llvm/lib/CodeGen/GlobalISel/MachineLegalizer.cpp b/llvm/lib/CodeGen/GlobalISel/MachineLegalizer.cpp
index cc3d4ecd7c6..5a15f65c45e 100644
--- a/llvm/lib/CodeGen/GlobalISel/MachineLegalizer.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/MachineLegalizer.cpp
@@ -30,8 +30,10 @@ MachineLegalizer::MachineLegalizer() : TablesInitialized(false) {
   DefaultActions[TargetOpcode::G_ANYEXT] = Legal;
   DefaultActions[TargetOpcode::G_TRUNC] = Legal;
 
-  // G_TYPE is essentially an annotated COPY so it's always legal.
+  // G_TYPE and G_PHI are essentially an annotated COPY/PHI instructions so
+  // they're always legal.
   DefaultActions[TargetOpcode::G_TYPE] = Legal;
+  DefaultActions[TargetOpcode::G_PHI] = Legal;
 
   DefaultActions[TargetOpcode::G_INTRINSIC] = Legal;
   DefaultActions[TargetOpcode::G_INTRINSIC_W_SIDE_EFFECTS] = Legal;
diff --git a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
index 779b624b0f7..26342a19546 100644
--- a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
@@ -235,6 +235,12 @@ bool AArch64InstructionSelector::select(MachineInstr &I) const {
     return true;
   }
 
+   case TargetOpcode::G_PHI: {
+     I.setDesc(TII.get(TargetOpcode::PHI));
+     I.removeTypes();
+     return true;
+   }
+
   case TargetOpcode::G_FRAME_INDEX: {
     // allocas and G_FRAME_INDEX are only supported in addrspace(0).
     if (I.getType() != LLT::pointer(0)) {