[GISEl]: Translate phi into G_PHI

G_PHI has the same semantics as PHI but also has types.
This lets us verify that the types in the G_PHI are consistent.
This also allows specifying legalization actions for G_PHIs.

https://reviews.llvm.org/D36990

llvm-svn: 311596

1 files changed, 17 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/MachineVerifier.cpp b/llvm/lib/CodeGen/MachineVerifier.cpp
index fcb5448..7429a7f 100644
--- a/llvm/lib/CodeGen/MachineVerifier.cpp
+++ b/llvm/lib/CodeGen/MachineVerifier.cpp
@@ -926,6 +926,23 @@ void MachineVerifier::visitMachineInstrBefore(const MachineInstr *MI) {
       report("Generic instruction accessing memory must have one mem operand",
              MI);
     break;
+  case TargetOpcode::G_PHI: {
+    LLT DstTy = MRI->getType(MI->getOperand(0).getReg());
+    if (!DstTy.isValid() ||
+        !std::all_of(MI->operands_begin() + 1, MI->operands_end(),
+                     [this, &DstTy](const MachineOperand &MO) {
+                       if (!MO.isReg())
+                         return true;
+                       LLT Ty = MRI->getType(MO.getReg());
+                       if (!Ty.isValid() || (Ty != DstTy))
+                         return false;
+                       return true;
+                     }))
+      report("Generic Instruction G_PHI has operands with incompatible/missing "
+             "types",
+             MI);
+    break;
+  }
   case TargetOpcode::STATEPOINT:
     if (!MI->getOperand(StatepointOpers::IDPos).isImm() ||
         !MI->getOperand(StatepointOpers::NBytesPos).isImm() ||