GlobalISel: legalize frem to a libcall on AArch64.

llvm-svn: 279988

1 files changed, 28 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/GlobalISel/MachineLegalizeHelper.cpp b/llvm/lib/CodeGen/GlobalISel/MachineLegalizeHelper.cpp
index b6ec2b89ad6..afc8289640b 100644
--- a/llvm/lib/CodeGen/GlobalISel/MachineLegalizeHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/MachineLegalizeHelper.cpp
@@ -14,10 +14,12 @@
 //===----------------------------------------------------------------------===//
 
 #include "llvm/CodeGen/GlobalISel/MachineLegalizeHelper.h"
+#include "llvm/CodeGen/GlobalISel/CallLowering.h"
 #include "llvm/CodeGen/GlobalISel/MachineLegalizer.h"
 #include "llvm/CodeGen/MachineRegisterInfo.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/raw_ostream.h"
+#include "llvm/Target/TargetLowering.h"
 #include "llvm/Target/TargetSubtargetInfo.h"
 
 #include <sstream>
@@ -38,6 +40,8 @@ MachineLegalizeHelper::legalizeInstrStep(MachineInstr &MI,
   switch (std::get<0>(Action)) {
   case MachineLegalizer::Legal:
     return AlreadyLegal;
+  case MachineLegalizer::Libcall:
+    return libcall(MI);
   case MachineLegalizer::NarrowScalar:
     return narrowScalar(MI, std::get<1>(Action), std::get<2>(Action));
   case MachineLegalizer::WidenScalar:
@@ -90,6 +94,30 @@ void MachineLegalizeHelper::extractParts(unsigned Reg, LLT Ty, int NumParts,
 }
 
 MachineLegalizeHelper::LegalizeResult
+MachineLegalizeHelper::libcall(MachineInstr &MI) {
+  unsigned Size = MI.getType().getSizeInBits();
+  MIRBuilder.setInstr(MI);
+
+  switch (MI.getOpcode()) {
+  default:
+    return UnableToLegalize;
+  case TargetOpcode::G_FREM: {
+    MVT Ty = MVT::getFloatingPointVT(MI.getType().getSizeInBits());
+    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);
+
+    CLI.lowerCall(MIRBuilder, MachineOperand::CreateES(Name), Ty,
+                  MI.getOperand(0).getReg(), {Ty, Ty},
+                  {MI.getOperand(1).getReg(), MI.getOperand(2).getReg()});
+    MI.eraseFromParent();
+    return Legalized;
+  }
+  }
+}
+
+MachineLegalizeHelper::LegalizeResult
 MachineLegalizeHelper::narrowScalar(MachineInstr &MI, unsigned TypeIdx,
                                     LLT NarrowTy) {
   // FIXME: Don't know how to handle secondary types yet.