6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-22 13:29:44 +00:00
Code Issues Projects Releases Wiki Activity

Be more aggressive about removing joined physreg copies.

Browse Source 
When a joined COPY changes subreg liveness, we keep it around as a KILL,
otherwise it is safe to delete.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@110403 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2010-08-05 23:51:28 +00:00
parent c910c8d2fa
commit f67202c94d
1 changed files with 10 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
lib/CodeGen/SimpleRegisterCoalescing.cpp
View File

@ -1726,7 +1726,8 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
bool DoDelete = true; bool DoDelete = true;
assert(MI->isCopyLike() && "Unrecognized copy instruction"); assert(MI->isCopyLike() && "Unrecognized copy instruction");
unsigned SrcReg = MI->getOperand(MI->isSubregToReg() ? 2 : 1).getReg(); unsigned SrcReg = MI->getOperand(MI->isSubregToReg() ? 2 : 1).getReg();
if (TargetRegisterInfo::isPhysicalRegister(SrcReg)) if (TargetRegisterInfo::isPhysicalRegister(SrcReg) &&
MI->getNumOperands() > 2)
// Do not delete extract_subreg, insert_subreg of physical // Do not delete extract_subreg, insert_subreg of physical
// registers unless the definition is dead. e.g. // registers unless the definition is dead. e.g.
// %DO<def> = INSERT_SUBREG %D0<undef>, %S0<kill>, 1 // %DO<def> = INSERT_SUBREG %D0<undef>, %S0<kill>, 1
@ -1740,9 +1741,15 @@ bool SimpleRegisterCoalescing::runOnMachineFunction(MachineFunction &fn) {
ShortenDeadCopyLiveRange(li, MI); ShortenDeadCopyLiveRange(li, MI);
DoDelete = true; DoDelete = true;
} }
if (!DoDelete) if (!DoDelete) {
// We need the instruction to adjust liveness, so make it a KILL.
if (MI->isSubregToReg()) {
MI->RemoveOperand(3);
MI->RemoveOperand(1);
}
MI->setDesc(tii_->get(TargetOpcode::KILL));
mii = llvm::next(mii); mii = llvm::next(mii);
else { } else {
li_->RemoveMachineInstrFromMaps(MI); li_->RemoveMachineInstrFromMaps(MI);
mii = mbbi->erase(mii); mii = mbbi->erase(mii);
++numPeep; ++numPeep;