[GlobalISel] Use the correct calling conv for calls

This commit adds a parameter that lets us pass in the calling convention
of the call to CallLowering::lowerCall. This allows us to handle
situations where the calling convetion of the callee is different from
that of the caller.

Differential Revision: https://reviews.llvm.org/D31039

llvm-svn: 298254
diff --git a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
index e45ae4a..b0fdf3b 100644
--- a/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/CallLowering.cpp
@@ -52,7 +52,7 @@
   if (!OrigRet.Ty->isVoidTy())
     setArgFlags(OrigRet, AttributeSet::ReturnIndex, DL, CS);
 
-  return lowerCall(MIRBuilder, Callee, OrigRet, OrigArgs);
+  return lowerCall(MIRBuilder, CS.getCallingConv(), Callee, OrigRet, OrigArgs);
 }
 
 template <typename FuncInfoTy>
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 7b09fd8..0f97469 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -523,7 +523,8 @@
     return false;
   }
 
-  return CLI->lowerCall(MIRBuilder, MachineOperand::CreateES(Callee),
+  return CLI->lowerCall(MIRBuilder, CI.getCallingConv(),
+                        MachineOperand::CreateES(Callee),
                         CallLowering::ArgInfo(0, CI.getType()), Args);
 }
 
diff --git a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
index af4747f..e26473d 100644
--- a/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp
@@ -114,11 +114,12 @@
     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(getRTLibDesc(MI.getOpcode(), Size));
+    auto Libcall = getRTLibDesc(MI.getOpcode(), Size);
+    const char *Name = TLI.getLibcallName(Libcall);
     MIRBuilder.getMF().getFrameInfo().setHasCalls(true);
     CLI.lowerCall(
-        MIRBuilder, MachineOperand::CreateES(Name),
-        {MI.getOperand(0).getReg(), Ty},
+        MIRBuilder, TLI.getLibcallCallingConv(Libcall),
+        MachineOperand::CreateES(Name), {MI.getOperand(0).getReg(), Ty},
         {{MI.getOperand(1).getReg(), Ty}, {MI.getOperand(2).getReg(), Ty}});
     MI.eraseFromParent();
     return Legalized;
diff --git a/llvm/lib/Target/AArch64/AArch64CallLowering.cpp b/llvm/lib/Target/AArch64/AArch64CallLowering.cpp
index 79e5221..f781ecb 100644
--- a/llvm/lib/Target/AArch64/AArch64CallLowering.cpp
+++ b/llvm/lib/Target/AArch64/AArch64CallLowering.cpp
@@ -302,6 +302,7 @@
 }
 
 bool AArch64CallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
+                                    CallingConv::ID CallConv,
                                     const MachineOperand &Callee,
                                     const ArgInfo &OrigRet,
                                     ArrayRef<ArgInfo> OrigArgs) const {
@@ -321,9 +322,9 @@
   // Find out which ABI gets to decide where things go.
   const AArch64TargetLowering &TLI = *getTLI<AArch64TargetLowering>();
   CCAssignFn *AssignFnFixed =
-      TLI.CCAssignFnForCall(F.getCallingConv(), /*IsVarArg=*/false);
+      TLI.CCAssignFnForCall(CallConv, /*IsVarArg=*/false);
   CCAssignFn *AssignFnVarArg =
-      TLI.CCAssignFnForCall(F.getCallingConv(), /*IsVarArg=*/true);
+      TLI.CCAssignFnForCall(CallConv, /*IsVarArg=*/true);
 
   auto CallSeqStart = MIRBuilder.buildInstr(AArch64::ADJCALLSTACKDOWN);
 
diff --git a/llvm/lib/Target/AArch64/AArch64CallLowering.h b/llvm/lib/Target/AArch64/AArch64CallLowering.h
index ec4a1e7..d96ce95 100644
--- a/llvm/lib/Target/AArch64/AArch64CallLowering.h
+++ b/llvm/lib/Target/AArch64/AArch64CallLowering.h
@@ -34,8 +34,8 @@
   bool lowerFormalArguments(MachineIRBuilder &MIRBuilder, const Function &F,
                             ArrayRef<unsigned> VRegs) const override;
 
-  bool lowerCall(MachineIRBuilder &MIRBuilder, const MachineOperand &Callee,
-                 const ArgInfo &OrigRet,
+  bool lowerCall(MachineIRBuilder &MIRBuilder, CallingConv::ID CallConv,
+                 const MachineOperand &Callee, const ArgInfo &OrigRet,
                  ArrayRef<ArgInfo> OrigArgs) const override;
 
 private:
diff --git a/llvm/lib/Target/ARM/ARMCallLowering.cpp b/llvm/lib/Target/ARM/ARMCallLowering.cpp
index 4662a5c..7485aaf 100644
--- a/llvm/lib/Target/ARM/ARMCallLowering.cpp
+++ b/llvm/lib/Target/ARM/ARMCallLowering.cpp
@@ -373,6 +373,7 @@
 } // End anonymous namespace.
 
 bool ARMCallLowering::lowerCall(MachineIRBuilder &MIRBuilder,
+                                CallingConv::ID CallConv,
                                 const MachineOperand &Callee,
                                 const ArgInfo &OrigRet,
                                 ArrayRef<ArgInfo> OrigArgs) const {
@@ -387,10 +388,6 @@
 
   auto CallSeqStart = MIRBuilder.buildInstr(ARM::ADJCALLSTACKDOWN);
 
-  // FIXME: This is the calling convention of the caller - we should use the
-  // calling convention of the callee instead.
-  auto CallConv = MF.getFunction()->getCallingConv();
-
   // Create the call instruction so we can add the implicit uses of arg
   // registers, but don't insert it yet.
   auto MIB = MIRBuilder.buildInstrNoInsert(ARM::BLX).add(Callee).addRegMask(
diff --git a/llvm/lib/Target/ARM/ARMCallLowering.h b/llvm/lib/Target/ARM/ARMCallLowering.h
index a712561..6404c7a 100644
--- a/llvm/lib/Target/ARM/ARMCallLowering.h
+++ b/llvm/lib/Target/ARM/ARMCallLowering.h
@@ -34,8 +34,8 @@
   bool lowerFormalArguments(MachineIRBuilder &MIRBuilder, const Function &F,
                             ArrayRef<unsigned> VRegs) const override;
 
-  bool lowerCall(MachineIRBuilder &MIRBuilder, const MachineOperand &Callee,
-                 const ArgInfo &OrigRet,
+  bool lowerCall(MachineIRBuilder &MIRBuilder, CallingConv::ID CallConv,
+                 const MachineOperand &Callee, const ArgInfo &OrigRet,
                  ArrayRef<ArgInfo> OrigArgs) const override;
 
 private: