diff options
| author | Chris Lattner <sabre@nondot.org> | 2005-04-09 15:23:56 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2005-04-09 15:23:56 +0000 |
| commit | 4c52f0ec8c41eff3ca88bd26d6da46c49209e3e9 (patch) | |
| tree | d55490dfbeddadd374ba0ee52aef650068c90dac /lib/Target/X86/X86ISelSimple.cpp | |
| parent | d493b34d31ddb37b2e2f0b24e00c4597cb1dcfd6 (diff) | |
Use live out sets for return values instead of imp_defs, which is cleaner and faster.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21181 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/X86ISelSimple.cpp')
| -rw-r--r-- | lib/Target/X86/X86ISelSimple.cpp | 29 |
1 files changed, 21 insertions, 8 deletions
diff --git a/lib/Target/X86/X86ISelSimple.cpp b/lib/Target/X86/X86ISelSimple.cpp index 48546aa54f..6c37b7095f 100644 --- a/lib/Target/X86/X86ISelSimple.cpp +++ b/lib/Target/X86/X86ISelSimple.cpp @@ -618,7 +618,8 @@ void X86ISel::LoadArgumentsToVirtualRegs(Function &Fn) { unsigned ArgOffset = 0; // Frame mechanisms handle retaddr slot MachineFrameInfo *MFI = F->getFrameInfo(); - for (Function::arg_iterator I = Fn.arg_begin(), E = Fn.arg_end(); I != E; ++I) { + for (Function::arg_iterator I = Fn.arg_begin(), E = Fn.arg_end(); + I != E; ++I) { bool ArgLive = !I->use_empty(); unsigned Reg = ArgLive ? getReg(*I) : 0; int FI; // Frame object index @@ -676,6 +677,25 @@ void X86ISel::LoadArgumentsToVirtualRegs(Function &Fn) { // llvm.va_start. if (Fn.getFunctionType()->isVarArg()) VarArgsFrameIndex = MFI->CreateFixedObject(1, ArgOffset); + + // Finally, inform the compiler what our live-outs will be, aka, what we will + // be returning in registers. + if (Fn.getReturnType() != Type::VoidTy) + switch (getClassB(Fn.getReturnType())) { + default: assert(0 && "Unknown type!"); + case cByte: + case cShort: + case cInt: + F->addLiveOut(X86::EAX); + break; + case cLong: + F->addLiveOut(X86::EAX); + F->addLiveOut(X86::EDX); + break; + case cFP: + F->addLiveOut(X86::ST0); + break; + } } /// EmitSpecialCodeForMain - Emit any code that needs to be executed only in @@ -1434,23 +1454,16 @@ void X86ISel::visitReturnInst(ReturnInst &I) { case cShort: case cInt: promote32(X86::EAX, ValueRecord(RetVal)); - // Declare that EAX is live on exit - BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::EAX).addReg(X86::ESP); break; case cFP: { // Floats & Doubles: Return in ST(0) unsigned RetReg = getReg(RetVal); BuildMI(BB, X86::FpSETRESULT, 1).addReg(RetReg); - // Declare that top-of-stack is live on exit - BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::ST0).addReg(X86::ESP); break; } case cLong: { unsigned RetReg = getReg(RetVal); BuildMI(BB, X86::MOV32rr, 1, X86::EAX).addReg(RetReg); BuildMI(BB, X86::MOV32rr, 1, X86::EDX).addReg(RetReg+1); - // Declare that EAX & EDX are live on exit - BuildMI(BB, X86::IMPLICIT_USE, 3).addReg(X86::EAX).addReg(X86::EDX) - .addReg(X86::ESP); break; } default: |