[GlobalISel] Add the necessary plumbing to lower formal arguments.
llvm-svn: 260579
diff --git a/llvm/include/llvm/Target/TargetLowering.h b/llvm/include/llvm/Target/TargetLowering.h
index 857e59a..4f38f64 100644
--- a/llvm/include/llvm/Target/TargetLowering.h
+++ b/llvm/include/llvm/Target/TargetLowering.h
@@ -33,6 +33,9 @@
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/CallingConv.h"
+#ifdef LLVM_BUILD_GLOBAL_ISEL
+# include "llvm/IR/Function.h"
+#endif
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InlineAsm.h"
#include "llvm/IR/Instructions.h"
@@ -2517,6 +2520,22 @@
unsigned VReg) const {
return false;
}
+
+ /// This hook must be implemented to lower the incoming (formal)
+ /// arguments, described by \p Args, for GlobalISel. Each argument
+ /// must end up in the related virtual register described by VRegs.
+ /// In other words, the first argument should end up in VRegs[0],
+ /// the second in VRegs[1], and so on.
+ /// \p MIRBuilder is set to the proper insertion for the argument
+ /// lowering.
+ ///
+ /// \return True if the lowering succeeded, false otherwise.
+ virtual bool
+ LowerFormalArguments(MachineIRBuilder &MIRBuilder,
+ const Function::ArgumentListType &Args,
+ const SmallVectorImpl<unsigned> &VRegs) const {
+ return false;
+ }
#endif
/// Return true if result of the specified node is used by a return node
diff --git a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
index 4368f92..8b93f45 100644
--- a/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
+++ b/llvm/lib/CodeGen/GlobalISel/IRTranslator.cpp
@@ -12,6 +12,7 @@
#include "llvm/CodeGen/GlobalISel/IRTranslator.h"
+#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/IR/Constant.h"
@@ -103,9 +104,22 @@
bool IRTranslator::runOnMachineFunction(MachineFunction &MF) {
const Function &F = *MF.getFunction();
+ if (F.empty())
+ return false;
TLI = MF.getSubtarget().getTargetLowering();
MIRBuilder.setFunction(MF);
MRI = &MF.getRegInfo();
+ // Setup the arguments.
+ MachineBasicBlock &MBB = getOrCreateBB(&F.front());
+ MIRBuilder.setBasicBlock(MBB);
+ SmallVector<unsigned, 8> VRegArgs;
+ for (const Argument &Arg: F.args())
+ VRegArgs.push_back(*getOrCreateVRegs(&Arg).begin());
+ bool Succeeded = TLI->LowerFormalArguments(MIRBuilder, F.getArgumentList(),
+ VRegArgs);
+ if (!Succeeded)
+ report_fatal_error("Unable to lower arguments");
+
for (const BasicBlock &BB: F) {
MachineBasicBlock &MBB = getOrCreateBB(&BB);
MIRBuilder.setBasicBlock(MBB);