6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-05 13:09:10 +00:00
Code Issues Projects Releases Wiki Activity

Register allocator is responsible for spilling callee saved regs

Browse Source 
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@5092 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Chris Lattner 2002-12-17 02:48:57 +00:00
parent 5b9cd61946
commit 6c6cf873f3
1 changed files with 3 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
lib/Target/X86/X86RegisterInfo.cpp
View File

@ -117,14 +117,6 @@ void X86RegisterInfo::emitPrologue(MachineFunction &MF,
MachineBasicBlock &MBB = MF.front(); // Prolog goes in entry BB
MachineBasicBlock::iterator MBBI = MBB.begin();
// PUSH all callee-save registers
const unsigned* regs = getCalleeSaveRegs();
while (*regs) {
MachineInstr *MI = BuildMI(X86::PUSHr32, 1).addReg(*regs);
MBBI = ++MBB.insert(MBBI, MI);
++regs;
}
// PUSH ebp
MachineInstr *MI = BuildMI(X86::PUSHr32, 1).addReg(X86::EBP);
MBBI = ++MBB.insert(MBBI, MI);
@ -144,15 +136,7 @@ void X86RegisterInfo::emitEpilogue(MachineBasicBlock &MBB,
assert((*MBBI)->getOpcode() == X86::RET &&
"Can only insert epilog into returning blocks");
// insert LEAVE
MBBI = ++MBB.insert(MBBI, BuildMI(X86::LEAVE, 0));
// POP all callee-save registers in REVERSE ORDER
static const unsigned regs[] = { X86::EBX, X86::EDI, X86::ESI,
MRegisterInfo::NoRegister };
unsigned idx = 0;
while (regs[idx]) {
MachineInstr *MI = BuildMI(X86::POPr32, 0, regs[idx++]);
MBBI = ++(MBB.insert(MBBI, MI));
}
// insert LEAVE: mov ESP, EBP; pop EBP
MBBI = ++MBB.insert(MBBI, BuildMI(X86::MOVrr32, 1,X86::ESP).addReg(X86::EBP));
MBBI = ++MBB.insert(MBBI, BuildMI(X86::POPr32, 1).addReg(X86::EBP));
}