GlobalISel: legalize G_FPOW to a libcall on AArch64.

There's no instruction to implement it.

llvm-svn: 294531

2 files changed, 16 insertions, 5 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index f41af0547a3..1f78243e115 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -92,6 +92,16 @@ void LegalizerHelper::extractParts(unsigned Reg, LLT Ty, int NumParts,
   MIRBuilder.buildExtract(VRegs, Indexes, Reg);
 }
 
+static RTLIB::Libcall getRTLibDesc(unsigned Opcode, unsigned Size) {
+  switch (Opcode) {
+  case TargetOpcode::G_FREM:
+    return Size == 64 ? RTLIB::REM_F64 : RTLIB::REM_F32;
+  case TargetOpcode::G_FPOW:
+    return Size == 64 ? RTLIB::POW_F64 : RTLIB::POW_F32;
+  }
+  llvm_unreachable("Unknown libcall function");
+}
+
 LegalizerHelper::LegalizeResult
 LegalizerHelper::libcall(MachineInstr &MI) {
   LLT Ty = MRI.getType(MI.getOperand(0).getReg());
@@ -101,14 +111,13 @@ LegalizerHelper::libcall(MachineInstr &MI) {
   switch (MI.getOpcode()) {
   default:
     return UnableToLegalize;
+  case TargetOpcode::G_FPOW:
   case TargetOpcode::G_FREM: {
     auto &Ctx = MIRBuilder.getMF().getFunction()->getContext();
     Type *Ty = Size == 64 ? Type::getDoubleTy(Ctx) : Type::getFloatTy(Ctx);
     auto &CLI = *MIRBuilder.getMF().getSubtarget().getCallLowering();
     auto &TLI = *MIRBuilder.getMF().getSubtarget().getTargetLowering();
-    const char *Name =
-        TLI.getLibcallName(Size == 64 ? RTLIB::REM_F64 : RTLIB::REM_F32);
-
+    const char *Name = TLI.getLibcallName(getRTLibDesc(MI.getOpcode(), Size));
     CLI.lowerCall(
         MIRBuilder, MachineOperand::CreateES(Name),
         {MI.getOperand(0).getReg(), Ty},
diff --git a/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp b/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp
index 32f9c5f80d0..c978be9ab10 100644
--- a/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp
+++ b/llvm/lib/Target/AArch64/AArch64LegalizerInfo.cpp
@@ -78,8 +78,10 @@ AArch64LegalizerInfo::AArch64LegalizerInfo() {
     for (auto Ty : {s32, s64})
       setAction({BinOp, Ty}, Legal);
 
-  setAction({G_FREM, s32}, Libcall);
-  setAction({G_FREM, s64}, Libcall);
+  for (unsigned BinOp : {G_FREM, G_FPOW}) {
+    setAction({BinOp, s32}, Libcall);
+    setAction({BinOp, s64}, Libcall);
+  }
 
   // FIXME: what should we do about G_INSERTs with more than one source value?
   // For now the default of not specifying means we'll fall back.