maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity

One more coalescer fix wrt deadness propagation. 

llvm-svn: 48837
This commit is contained in:
Evan Cheng 2008-03-26 20:15:49 +00:00
parent 289ba4f335
commit db390694ff
2 changed files with 50 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
llvm/lib/CodeGen/SimpleRegisterCoalescing.cpp
View File

@ -554,6 +554,23 @@ void SimpleRegisterCoalescing::ShortenDeadCopyLiveRange(LiveInterval &li,
}
}
/// PropagateDeadness - Propagate the dead marker to the instruction which
/// defines the val#.
static void PropagateDeadness(LiveInterval &li, MachineInstr *CopyMI,
unsigned &LRStart, LiveIntervals *li_,
const TargetRegisterInfo* tri_) {
MachineInstr *DefMI =
li_->getInstructionFromIndex(li_->getDefIndex(LRStart));
if (DefMI && DefMI != CopyMI) {
int DeadIdx = DefMI->findRegisterDefOperandIdx(li.reg, false, tri_);
if (DeadIdx != -1) {
DefMI->getOperand(DeadIdx).setIsDead();
// A dead def should have a single cycle interval.
++LRStart;
}
}
}
/// ShortenDeadCopyLiveRange - Shorten a live range as it's artificially
/// extended by a dead copy. Mark the last use (if any) of the val# as kill
/// as ends the live range there. If there isn't another use, then this
@ -613,23 +630,14 @@ SimpleRegisterCoalescing::ShortenDeadCopySrcLiveRange(LiveInterval &li,
// Live-in to the function but dead. Remove it from entry live-in set.
mf_->begin()->removeLiveIn(li.reg);
}
removeRange(li, LR->start, LR->end, li_, tri_);
// FIXME: Shorten intervals in BBs that reaches this BB.
} else {
// Not livein into BB.
MachineInstr *DefMI =
li_->getInstructionFromIndex(li_->getDefIndex(RemoveStart));
if (DefMI && DefMI != CopyMI) {
int DeadIdx = DefMI->findRegisterDefOperandIdx(li.reg, false, tri_);
if (DeadIdx != -1) {
DefMI->getOperand(DeadIdx).setIsDead();
// A dead def should have a single cycle interval.
++RemoveStart;
}
}
removeRange(li, RemoveStart, LR->end, li_, tri_);
}
if (LR->valno->def == RemoveStart)
// If the def MI defines the val#, propagate the dead marker.
PropagateDeadness(li, CopyMI, RemoveStart, li_, tri_);
removeRange(li, RemoveStart, LR->end, li_, tri_);
removeIntervalIfEmpty(li, li_, tri_);
}

28
llvm/test/CodeGen/PowerPC/2008-03-26-CoalescerBug.ll Normal file
View File

@ -0,0 +1,28 @@
; RUN: llvm-as < %s | llc -mtriple=powerpc-apple-darwin
define i32 @t(i64 %byteStart, i32 %activeIndex) nounwind {
entry:
%tmp50 = load i32* null, align 4 ; <i32> [#uses=1]
%tmp5051 = zext i32 %tmp50 to i64 ; <i64> [#uses=3]
%tmp53 = udiv i64 %byteStart, %tmp5051 ; <i64> [#uses=1]
%tmp5354 = trunc i64 %tmp53 to i32 ; <i32> [#uses=1]
%tmp62 = urem i64 %byteStart, %tmp5051 ; <i64> [#uses=1]
%tmp94 = add i32 0, 1 ; <i32> [#uses=1]
%tmp100 = urem i32 %tmp94, 0 ; <i32> [#uses=2]
%tmp108 = add i32 0, %activeIndex ; <i32> [#uses=1]
%tmp110 = sub i32 %tmp108, 0 ; <i32> [#uses=1]
%tmp112 = urem i32 %tmp110, 0 ; <i32> [#uses=2]
%tmp122 = icmp ult i32 %tmp112, %tmp100 ; <i1> [#uses=1]
%iftmp.175.0 = select i1 %tmp122, i32 %tmp112, i32 %tmp100 ; <i32> [#uses=1]
%tmp119 = add i32 %tmp5354, 0 ; <i32> [#uses=1]
%tmp131 = add i32 %tmp119, %iftmp.175.0 ; <i32> [#uses=1]
%tmp131132 = zext i32 %tmp131 to i64 ; <i64> [#uses=1]
%tmp147 = mul i64 %tmp131132, %tmp5051 ; <i64> [#uses=1]
br i1 false, label %bb164, label %bb190
bb164: ; preds = %entry
%tmp171172 = and i64 %tmp62, 4294967295 ; <i64> [#uses=1]
%tmp173 = add i64 %tmp171172, %tmp147 ; <i64> [#uses=0]
ret i32 0
bb190: ; preds = %entry
ret i32 0
}