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Don't mark a register live at an undef use. 

llvm-svn: 80621
This commit is contained in:
David Goodwin 2009-08-31 20:47:02 +00:00
parent d9b6115f27
commit c8985204d9
2 changed files with 34 additions and 13 deletions
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21
llvm/lib/CodeGen/PostRASchedulerList.cpp
View File

@ -310,11 +310,11 @@ void SchedulePostRATDList::StartBlock(MachineBasicBlock *BB) {
// prologue/epilogue insertion so there's no way to add additional
// saved registers.
//
// TODO: If the callee saves and restores these, then we can potentially
// use them between the save and the restore. To do that, we could scan
// the exit blocks to see which of these registers are defined.
// Alternatively, callee-saved registers that aren't saved and restored
// could be marked live-in in every block.
// TODO: there is a new method
// MachineFrameInfo::getPristineRegs(MBB). It gives you a list of
// CSRs that have not been saved when entering the MBB. The
// remaining CSRs have been saved and can be treated like call
// clobbered registers.
for (const unsigned *I = TRI->getCalleeSavedRegs(); *I; ++I) {
unsigned Reg = *I;
Classes[Reg] = reinterpret_cast<TargetRegisterClass *>(-1);
@ -788,7 +788,6 @@ void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
I != E; --Count) {
MachineInstr *MI = --I;
DEBUG(MI->dump());
// Update liveness. Registers that are defed but not used in this
// instruction are now dead. Mark register and all subregs as they
// are completely defined.
@ -801,8 +800,6 @@ void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
// Ignore two-addr defs.
if (MI->isRegTiedToUseOperand(i)) continue;
DEBUG(errs() << "*** Handling Defs " << TM.getRegisterInfo()->get(Reg).Name << '\n');
KillIndices[Reg] = ~0u;
// Repeat for all subregs.
@ -822,8 +819,6 @@ void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
unsigned Reg = MO.getReg();
if ((Reg == 0) || ReservedRegs.test(Reg)) continue;
DEBUG(errs() << "*** Handling Uses " << TM.getRegisterInfo()->get(Reg).Name << '\n');
bool kill = false;
if (killedRegs.find(Reg) == killedRegs.end()) {
kill = true;
@ -851,14 +846,14 @@ void SchedulePostRATDList::FixupKills(MachineBasicBlock *MBB) {
killedRegs.insert(Reg);
}
// Mark any used register and subregs as now live...
// Mark any used register (that is not using undef) and subregs as
// now live...
for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI->getOperand(i);
if (!MO.isReg() || !MO.isUse()) continue;
if (!MO.isReg() || !MO.isUse() || MO.isUndef()) continue;
unsigned Reg = MO.getReg();
if ((Reg == 0) || ReservedRegs.test(Reg)) continue;
DEBUG(errs() << "Killing " << TM.getRegisterInfo()->get(Reg).Name << '\n');
KillIndices[Reg] = Count;
for (const unsigned *Subreg = TRI->getSubRegisters(Reg);

26
llvm/test/CodeGen/ARM/2009-08-21-PostRAKill4.ll Normal file
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@ -0,0 +1,26 @@
; RUN: llvm-as < %s | llc -asm-verbose=false -O3 -relocation-model=pic -disable-fp-elim -mtriple=thumbv7-apple-darwin -mcpu=cortex-a8 -disable-post-RA-scheduler=0 -avoid-hazards
; ModuleID = '<stdin>'
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:32-f32:32:32-f64:32:32-v64:64:64-v128:128:128-a0:0:64"
target triple = "armv7-apple-darwin9"
@.str = external constant [36 x i8], align 1 ; <[36 x i8]*> [#uses=0]
@.str1 = external constant [31 x i8], align 1 ; <[31 x i8]*> [#uses=1]
@.str2 = external constant [4 x i8], align 1 ; <[4 x i8]*> [#uses=1]
declare arm_apcscc i32 @getUnknown(i32, ...) nounwind
declare void @llvm.va_start(i8*) nounwind
declare void @llvm.va_end(i8*) nounwind
declare arm_apcscc i32 @printf(i8* nocapture, ...) nounwind
define arm_apcscc i32 @main() nounwind {
entry:
%0 = tail call arm_apcscc i32 (i8*, ...)* @printf(i8* getelementptr ([31 x i8]* @.str1, i32 0, i32 0), i32 1, i32 1, i32 1, i32 1, i32 1, i32 1) nounwind ; <i32> [#uses=0]
%1 = tail call arm_apcscc i32 (i8*, ...)* @printf(i8* getelementptr ([31 x i8]* @.str1, i32 0, i32 0), i32 -128, i32 116, i32 116, i32 -3852, i32 -31232, i32 -1708916736) nounwind ; <i32> [#uses=0]
%2 = tail call arm_apcscc i32 (i32, ...)* @getUnknown(i32 undef, i32 116, i32 116, i32 -3852, i32 -31232, i32 30556, i32 -1708916736) nounwind ; <i32> [#uses=1]
%3 = tail call arm_apcscc i32 (i8*, ...)* @printf(i8* getelementptr ([4 x i8]* @.str2, i32 0, i32 0), i32 %2) nounwind ; <i32> [#uses=0]
ret i32 0
}