[llvm-commits] [llvm] r82834 - in /llvm/trunk/lib/CodeGen: MachineLICM.cpp MachineSink.cpp
Dan Gohman
gohman at apple.com
Fri Sep 25 19:34:00 PDT 2009
Author: djg
Date: Fri Sep 25 21:34:00 2009
New Revision: 82834
URL: http://llvm.org/viewvc/llvm-project?rev=82834&view=rev
Log:
Don't hoist or sink instructions with physreg uses if the physreg is
allocatable. Even if it doesn't appear to have any defs, it may latter
on after register allocation.
Modified:
llvm/trunk/lib/CodeGen/MachineLICM.cpp
llvm/trunk/lib/CodeGen/MachineSink.cpp
Modified: llvm/trunk/lib/CodeGen/MachineLICM.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineLICM.cpp?rev=82834&r1=82833&r2=82834&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineLICM.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineLICM.cpp Fri Sep 25 21:34:00 2009
@@ -44,6 +44,7 @@
const TargetMachine *TM;
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
+ BitVector AllocatableSet;
// Various analyses that we use...
MachineLoopInfo *LI; // Current MachineLoopInfo
@@ -138,6 +139,7 @@
TII = TM->getInstrInfo();
TRI = TM->getRegisterInfo();
RegInfo = &MF.getRegInfo();
+ AllocatableSet = TRI->getAllocatableSet(MF);
// Get our Loop information...
LI = &getAnalysis<MachineLoopInfo>();
@@ -261,13 +263,20 @@
// we can move it, but only if the def is dead.
if (MO.isUse()) {
// If the physreg has no defs anywhere, it's just an ambient register
- // and we can freely move its uses.
+ // and we can freely move its uses. Alternatively, if it's allocatable,
+ // it could get allocated to something with a def during allocation.
if (!RegInfo->def_empty(Reg))
return false;
+ if (AllocatableSet.test(Reg))
+ return false;
// Check for a def among the register's aliases too.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias)
- if (!RegInfo->def_empty(*Alias))
+ for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
+ unsigned AliasReg = *Alias;
+ if (!RegInfo->def_empty(AliasReg))
+ return false;
+ if (AllocatableSet.test(AliasReg))
return false;
+ }
// Otherwise it's safe to move.
continue;
} else if (!MO.isDead()) {
Modified: llvm/trunk/lib/CodeGen/MachineSink.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineSink.cpp?rev=82834&r1=82833&r2=82834&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineSink.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineSink.cpp Fri Sep 25 21:34:00 2009
@@ -39,6 +39,7 @@
MachineFunction *CurMF; // Current MachineFunction
MachineRegisterInfo *RegInfo; // Machine register information
MachineDominatorTree *DT; // Machine dominator tree
+ BitVector AllocatableSet; // Which physregs are allocatable?
public:
static char ID; // Pass identification
@@ -99,6 +100,7 @@
TRI = TM->getRegisterInfo();
RegInfo = &CurMF->getRegInfo();
DT = &getAnalysis<MachineDominatorTree>();
+ AllocatableSet = TRI->getAllocatableSet(*CurMF);
bool EverMadeChange = false;
@@ -180,13 +182,20 @@
// we can move it, but only if the def is dead.
if (MO.isUse()) {
// If the physreg has no defs anywhere, it's just an ambient register
- // and we can freely move its uses.
+ // and we can freely move its uses. Alternatively, if it's allocatable,
+ // it could get allocated to something with a def during allocation.
if (!RegInfo->def_empty(Reg))
return false;
+ if (AllocatableSet.test(Reg))
+ return false;
// Check for a def among the register's aliases too.
- for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias)
- if (!RegInfo->def_empty(*Alias))
+ for (const unsigned *Alias = TRI->getAliasSet(Reg); *Alias; ++Alias) {
+ unsigned AliasReg = *Alias;
+ if (!RegInfo->def_empty(AliasReg))
+ return false;
+ if (AllocatableSet.test(AliasReg))
return false;
+ }
} else if (!MO.isDead()) {
// A def that isn't dead. We can't move it.
return false;
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