GlobalISel: support selecting fpext/fptrunc instructions on AArch64.

llvm-svn: 286253

1 files changed, 54 insertions, 0 deletions

diff --git a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
index 80ea8d6d61d..ac8323ac624 100644
--- a/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
+++ b/llvm/lib/Target/AArch64/AArch64InstructionSelector.cpp
@@ -953,6 +953,60 @@ bool AArch64InstructionSelector::select(MachineInstr &I) const {
   case TargetOpcode::G_BITCAST:
     return selectCopy(I, TII, MRI, TRI, RBI);
 
+  case TargetOpcode::G_FPEXT: {
+    if (MRI.getType(I.getOperand(0).getReg()) != LLT::scalar(64)) {
+      DEBUG(dbgs() << "G_FPEXT to type " << Ty
+                   << ", expected: " << LLT::scalar(64) << '\n');
+      return false;
+    }
+
+    if (MRI.getType(I.getOperand(1).getReg()) != LLT::scalar(32)) {
+      DEBUG(dbgs() << "G_FPEXT from type " << Ty
+                   << ", expected: " << LLT::scalar(32) << '\n');
+      return false;
+    }
+
+    const unsigned DefReg = I.getOperand(0).getReg();
+    const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
+
+    if (RB.getID() != AArch64::FPRRegBankID) {
+      DEBUG(dbgs() << "G_FPEXT on bank: " << RB << ", expected: FPR\n");
+      return false;
+    }
+
+    I.setDesc(TII.get(AArch64::FCVTDSr));
+    constrainSelectedInstRegOperands(I, TII, TRI, RBI);
+
+    return true;
+  }
+
+  case TargetOpcode::G_FPTRUNC: {
+    if (MRI.getType(I.getOperand(0).getReg()) != LLT::scalar(32)) {
+      DEBUG(dbgs() << "G_FPTRUNC to type " << Ty
+                   << ", expected: " << LLT::scalar(32) << '\n');
+      return false;
+    }
+
+    if (MRI.getType(I.getOperand(1).getReg()) != LLT::scalar(64)) {
+      DEBUG(dbgs() << "G_FPTRUNC from type " << Ty
+                   << ", expected: " << LLT::scalar(64) << '\n');
+      return false;
+    }
+
+    const unsigned DefReg = I.getOperand(0).getReg();
+    const RegisterBank &RB = *RBI.getRegBank(DefReg, MRI, TRI);
+
+    if (RB.getID() != AArch64::FPRRegBankID) {
+      DEBUG(dbgs() << "G_FPTRUNC on bank: " << RB << ", expected: FPR\n");
+      return false;
+    }
+
+    I.setDesc(TII.get(AArch64::FCVTSDr));
+    constrainSelectedInstRegOperands(I, TII, TRI, RBI);
+
+    return true;
+  }
+
   case TargetOpcode::G_SELECT: {
     if (MRI.getType(I.getOperand(1).getReg()) != LLT::scalar(1)) {
       DEBUG(dbgs() << "G_SELECT cond has type: " << Ty