Implicitly defined registers can clobber callee saved registers too!

This fixes the return-address-not-being-saved problem in the Alpha backend.

llvm-svn: 19741
This commit is contained in:
Chris Lattner 2005-01-22 00:49:16 +00:00
parent e3d81200bc
commit 29d6389d78

View File

@ -96,6 +96,7 @@ FunctionPass *llvm::createPrologEpilogCodeInserter() { return new PEI(); }
void PEI::calculateCallerSavedRegisters(MachineFunction &Fn) {
const MRegisterInfo *RegInfo = Fn.getTarget().getRegisterInfo();
const TargetFrameInfo *TFI = Fn.getTarget().getFrameInfo();
const TargetInstrInfo &TII = *Fn.getTarget().getInstrInfo();
// Get the callee saved register list...
const unsigned *CSRegs = RegInfo->getCalleeSaveRegs();
@ -133,6 +134,11 @@ void PEI::calculateCallerSavedRegisters(MachineFunction &Fn) {
"Register allocation must be performed!");
ModifiedRegs[MO.getReg()] = true; // Register is modified
}
// Mark any implicitly defined registers as being modified.
for (const unsigned *ImpDefs = TII.getImplicitDefs(I->getOpcode());
*ImpDefs; ++ImpDefs)
ModifiedRegs[*ImpDefs] = true;
}
++I;
}