Teach taildup to update livein set. rdar://11538365

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157663 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Evan Cheng 2012-05-30 00:42:39 +00:00
parent 3d4166dff0
commit eb25bd2356
2 changed files with 165 additions and 0 deletions

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@ -20,7 +20,9 @@
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/MachineSSAUpdater.h"
#include "llvm/CodeGen/RegisterScavenging.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetRegisterInfo.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
@ -57,8 +59,10 @@ namespace {
/// TailDuplicatePass - Perform tail duplication.
class TailDuplicatePass : public MachineFunctionPass {
const TargetInstrInfo *TII;
const TargetRegisterInfo *TRI;
MachineModuleInfo *MMI;
MachineRegisterInfo *MRI;
RegScavenger *RS;
bool PreRegAlloc;
// SSAUpdateVRs - A list of virtual registers for which to update SSA form.
@ -124,9 +128,13 @@ INITIALIZE_PASS(TailDuplicatePass, "tailduplication", "Tail Duplication",
bool TailDuplicatePass::runOnMachineFunction(MachineFunction &MF) {
TII = MF.getTarget().getInstrInfo();
TRI = MF.getTarget().getRegisterInfo();
MRI = &MF.getRegInfo();
MMI = getAnalysisIfAvailable<MachineModuleInfo>();
PreRegAlloc = MRI->isSSA();
RS = NULL;
if (MRI->tracksLiveness() && TRI->trackLivenessAfterRegAlloc(MF))
RS = new RegScavenger();
bool MadeChange = false;
while (TailDuplicateBlocks(MF))
@ -777,6 +785,23 @@ TailDuplicatePass::TailDuplicate(MachineBasicBlock *TailBB,
// Remove PredBB's unconditional branch.
TII->RemoveBranch(*PredBB);
if (RS && !TailBB->livein_empty()) {
// Update PredBB livein.
RS->enterBasicBlock(PredBB);
if (!PredBB->empty())
RS->forward(prior(PredBB->end()));
BitVector RegsLiveAtExit(TRI->getNumRegs());
RS->getRegsUsed(RegsLiveAtExit, false);
for (MachineBasicBlock::livein_iterator I = TailBB->livein_begin(),
E = TailBB->livein_end(); I != E; ++I) {
if (!RegsLiveAtExit[*I])
// If a register is previously livein to the tail but it's not live
// at the end of predecessor BB, then it should be added to its
// livein list.
PredBB->addLiveIn(*I);
}
}
// Clone the contents of TailBB into PredBB.
DenseMap<unsigned, unsigned> LocalVRMap;
SmallVector<std::pair<unsigned,unsigned>, 4> CopyInfos;

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@ -0,0 +1,140 @@
; RUN: llc -mtriple=thumbv7-apple-ios -mcpu=cortex-a8 -verify-machineinstrs < %s
; Teach taildup to update livein set to appease verifier.
; rdar://11538365
%struct.__CFString.2 = type opaque
declare void @CFRelease(i8*)
define hidden fastcc i32 @t() ssp {
entry:
%mylocale.i.i = alloca [256 x i8], align 1
br i1 undef, label %return, label %CFStringIsHyphenationAvailableForLocale.exit
CFStringIsHyphenationAvailableForLocale.exit: ; preds = %entry
br i1 undef, label %return, label %if.end
if.end: ; preds = %CFStringIsHyphenationAvailableForLocale.exit
br i1 undef, label %if.end8.thread.i, label %if.then.i
if.then.i: ; preds = %if.end
br i1 undef, label %if.end8.thread.i, label %if.end8.i
if.end8.thread.i: ; preds = %if.then.i, %if.end
unreachable
if.end8.i: ; preds = %if.then.i
br i1 undef, label %if.then11.i, label %__CFHyphenationPullTokenizer.exit
if.then11.i: ; preds = %if.end8.i
unreachable
__CFHyphenationPullTokenizer.exit: ; preds = %if.end8.i
br i1 undef, label %if.end68, label %if.then3
if.then3: ; preds = %__CFHyphenationPullTokenizer.exit
br i1 undef, label %cond.end, label %cond.false
cond.false: ; preds = %if.then3
br label %cond.end
cond.end: ; preds = %cond.false, %if.then3
br i1 undef, label %while.end, label %while.body
while.body: ; preds = %cond.end
unreachable
while.end: ; preds = %cond.end
br i1 undef, label %if.end5.i, label %if.then.i16
if.then.i16: ; preds = %while.end
br i1 undef, label %if.then4.i, label %if.end5.i
if.then4.i: ; preds = %if.then.i16
br i1 false, label %cleanup.thread, label %if.end.i20
if.end5.i: ; preds = %if.then.i16, %while.end
unreachable
if.end.i20: ; preds = %if.then4.i
br label %for.body.i146.i
for.body.i146.i: ; preds = %for.body.i146.i, %if.end.i20
br i1 undef, label %if.end20.i, label %for.body.i146.i
if.end20.i: ; preds = %for.body.i146.i
br i1 undef, label %cleanup.thread, label %if.end23.i
if.end23.i: ; preds = %if.end20.i
br label %for.body.i94.i
for.body.i94.i: ; preds = %for.body.i94.i, %if.end23.i
br i1 undef, label %if.then28.i, label %for.body.i94.i
if.then28.i: ; preds = %for.body.i94.i
br i1 undef, label %cond.true.i26, label %land.lhs.true
cond.true.i26: ; preds = %if.then28.i
br label %land.lhs.true
land.lhs.true: ; preds = %cond.true.i26, %if.then28.i
br i1 false, label %cleanup.thread, label %if.end35
if.end35: ; preds = %land.lhs.true
br i1 undef, label %cleanup.thread, label %if.end45
if.end45: ; preds = %if.end35
br i1 undef, label %if.then50, label %if.end.i37
if.end.i37: ; preds = %if.end45
br label %if.then50
if.then50: ; preds = %if.end.i37, %if.end45
br i1 undef, label %__CFHyphenationGetHyphensForString.exit, label %if.end.i
if.end.i: ; preds = %if.then50
br i1 undef, label %cleanup.i, label %cond.true.i
cond.true.i: ; preds = %if.end.i
br i1 undef, label %for.cond16.preheader.i, label %for.cond57.preheader.i
for.cond16.preheader.i: ; preds = %cond.true.i
%cmp1791.i = icmp sgt i32 undef, 1
br i1 %cmp1791.i, label %for.body18.i, label %for.cond57.preheader.i
for.cond57.preheader.i: ; preds = %for.cond16.preheader.i, %cond.true.i
%sub69.i = add i32 undef, -2
br label %cleanup.i
for.body18.i: ; preds = %for.cond16.preheader.i
store i16 0, i16* undef, align 2
br label %while.body.i
while.body.i: ; preds = %while.body.i, %for.body18.i
br label %while.body.i
cleanup.i: ; preds = %for.cond57.preheader.i, %if.end.i
br label %__CFHyphenationGetHyphensForString.exit
__CFHyphenationGetHyphensForString.exit: ; preds = %cleanup.i, %if.then50
%retval.1.i = phi i32 [ 0, %cleanup.i ], [ -1, %if.then50 ]
%phitmp = bitcast %struct.__CFString.2* null to i8*
br label %if.end68
cleanup.thread: ; preds = %if.end35, %land.lhs.true, %if.end20.i, %if.then4.i
call void @llvm.stackrestore(i8* null)
br label %return
if.end68: ; preds = %__CFHyphenationGetHyphensForString.exit, %__CFHyphenationPullTokenizer.exit
%hyphenCount.2 = phi i32 [ %retval.1.i, %__CFHyphenationGetHyphensForString.exit ], [ 0, %__CFHyphenationPullTokenizer.exit ]
%_token.1 = phi i8* [ %phitmp, %__CFHyphenationGetHyphensForString.exit ], [ undef, %__CFHyphenationPullTokenizer.exit ]
call void @CFRelease(i8* %_token.1)
br label %return
return: ; preds = %if.end68, %cleanup.thread, %CFStringIsHyphenationAvailableForLocale.exit, %entry
%retval.1 = phi i32 [ %hyphenCount.2, %if.end68 ], [ -1, %CFStringIsHyphenationAvailableForLocale.exit ], [ -1, %cleanup.thread ], [ -1, %entry ]
ret i32 %retval.1
}
declare void @llvm.stackrestore(i8*) nounwind