Emit pseudo instructions to indicate that some registers are live on entrance

and exit of the function.  This fixes bug: Jello/2003-05-06-LivenessClobber.llx
and the Fhourstones benchmark

llvm-svn: 6010
This commit is contained in:
Chris Lattner 2003-05-06 21:32:22 +00:00
parent b6fab2a875
commit 54c4b56baf

View File

@ -78,6 +78,11 @@ namespace {
F->getBasicBlockList().push_back(MBBMap[I] = new MachineBasicBlock(I));
BB = &F->front();
// Declare that the stack pointer is live on entrance to the function
BuildMI(BB, X86::IMPLICIT_DEF, 0, X86::ESP);
// Copy incoming arguments off of the stack...
LoadArgumentsToVirtualRegs(Fn);
// Instruction select everything except PHI nodes
@ -671,13 +676,19 @@ void ISel::visitReturnInst(ReturnInst &I) {
case cShort:
case cInt:
promote32(X86::EAX, ValueRecord(RetReg, RetVal->getType()));
// Declare that EAX is live on exit
BuildMI(BB, X86::IMPLICIT_USE, 1).addReg(X86::EAX);
break;
case cFP: // Floats & Doubles: Return in ST(0)
BuildMI(BB, X86::FpSETRESULT, 1).addReg(RetReg);
// Declare that top-of-stack is live on exit
BuildMI(BB, X86::IMPLICIT_USE, 1).addReg(X86::ST0);
break;
case cLong:
BuildMI(BB, X86::MOVrr32, 1, X86::EAX).addReg(RetReg);
BuildMI(BB, X86::MOVrr32, 1, X86::EDX).addReg(RetReg+1);
// Declare that EAX & EDX are live on exit
BuildMI(BB, X86::IMPLICIT_USE, 2).addReg(X86::EAX).addReg(X86::EDX);
break;
default:
visitInstruction(I);