Only erase virtregs with no uses left.

Also make sure registers aren't erased twice if the dead def mentions
the register twice.

This fixes PR12911.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157254 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Jakob Stoklund Olesen 2012-05-22 14:52:12 +00:00
parent 5cdbb1de7d
commit 76ff741836
2 changed files with 133 additions and 4 deletions

View File

@ -220,6 +220,9 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
DEBUG(dbgs() << "Deleting dead def " << Idx << '\t' << *MI);
// Collect virtual registers to be erased after MI is gone.
SmallVector<unsigned, 8> RegsToErase;
// Check for live intervals that may shrink
for (MachineInstr::mop_iterator MOI = MI->operands_begin(),
MOE = MI->operands_end(); MOI != MOE; ++MOI) {
@ -245,10 +248,8 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
if (TheDelegate)
TheDelegate->LRE_WillShrinkVirtReg(LI.reg);
LI.removeValNo(VNI);
if (LI.empty()) {
ToShrink.remove(&LI);
eraseVirtReg(Reg);
}
if (LI.empty())
RegsToErase.push_back(Reg);
}
}
}
@ -258,6 +259,16 @@ void LiveRangeEdit::eliminateDeadDefs(SmallVectorImpl<MachineInstr*> &Dead,
LIS.RemoveMachineInstrFromMaps(MI);
MI->eraseFromParent();
++NumDCEDeleted;
// Erase any virtregs that are now empty and unused. There may be <undef>
// uses around. Keep the empty live range in that case.
for (unsigned i = 0, e = RegsToErase.size(); i != e; ++i) {
unsigned Reg = RegsToErase[i];
if (LIS.hasInterval(Reg) && MRI.reg_nodbg_empty(Reg)) {
ToShrink.remove(&LIS.getInterval(Reg));
eraseVirtReg(Reg);
}
}
}
if (ToShrink.empty())

View File

@ -0,0 +1,118 @@
; RUN: llc < %s -verify-coalescing
; PR12911
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-apple-macosx10.7.0"
@d = common global i32 0, align 4
@c = common global i32 0, align 4
@b = common global i32 0, align 4
@h = common global i32 0, align 4
@f = common global i32 0, align 4
@g = common global i32 0, align 4
@a = common global i16 0, align 2
@e = common global i32 0, align 4
define void @fn1() nounwind uwtable ssp {
entry:
%0 = load i32* @d, align 4
%tobool72 = icmp eq i32 %0, 0
br i1 %tobool72, label %for.end32, label %for.cond1.preheader.lr.ph
for.cond1.preheader.lr.ph: ; preds = %entry
%1 = load i32* @c, align 4
%tobool2 = icmp eq i32 %1, 0
%2 = load i32* @b, align 4
%cmp = icmp sgt i32 %2, 0
%conv = zext i1 %cmp to i32
%3 = load i32* @g, align 4
%tobool4 = icmp eq i32 %3, 0
%4 = load i16* @a, align 2
%tobool9 = icmp eq i16 %4, 0
br label %for.cond1.preheader
for.cond1.preheader: ; preds = %for.cond25.loopexit.us-lcssa.us-lcssa, %if.end.us50, %if.end.us, %if.end.us.us, %for.cond1.preheader.lr.ph
%j.073 = phi i32 [ undef, %for.cond1.preheader.lr.ph ], [ %j.1.us.us, %if.end.us.us ], [ %j.1.us, %if.end.us ], [ %j.073, %for.cond25.loopexit.us-lcssa.us-lcssa ], [ %j.1.us36, %if.end.us50 ]
br i1 %tobool2, label %for.cond1.preheader.split.us, label %for.cond1.preheader.for.cond1.preheader.split_crit_edge
for.cond1.preheader.for.cond1.preheader.split_crit_edge: ; preds = %for.cond1.preheader
br i1 %tobool9, label %if.end.us50, label %for.cond1.preheader.split.for.cond1.preheader.split.split_crit_edge
for.cond1.preheader.split.us: ; preds = %for.cond1.preheader
br i1 %tobool9, label %cond.end.us.us, label %cond.end.us
cond.false18.us.us: ; preds = %if.end.us.us
%5 = load i32* @f, align 4
%sext76 = shl i32 %5, 16
%phitmp75 = ashr exact i32 %sext76, 16
br label %cond.end.us.us
if.end.us.us: ; preds = %cond.end.us.us, %if.then.us.us
br i1 %tobool4, label %cond.false18.us.us, label %for.cond1.preheader
if.then.us.us: ; preds = %cond.end.us.us
store i32 0, i32* @f, align 4
br label %if.end.us.us
cond.end.us.us: ; preds = %cond.false18.us.us, %for.cond1.preheader.split.us
%j.1.us.us = phi i32 [ %j.073, %for.cond1.preheader.split.us ], [ %phitmp75, %cond.false18.us.us ]
store i32 %conv, i32* @h, align 4
br i1 %cmp, label %if.then.us.us, label %if.end.us.us
cond.end21.us: ; preds = %land.lhs.true12.us, %cond.false18.us
%cond22.us = phi i16 [ %add.us, %cond.false18.us ], [ %4, %land.lhs.true12.us ]
%conv24.us = sext i16 %cond22.us to i32
br label %cond.end.us
cond.false18.us: ; preds = %if.end6.us, %land.lhs.true12.us
%add.us = add i16 %4, %conv7.us
br label %cond.end21.us
land.lhs.true12.us: ; preds = %if.end6.us
%conv10.us = sext i16 %conv7.us to i32
%sub.us = sub nsw i32 0, %conv10.us
%cmp14.us = icmp slt i32 %sub.us, 1
br i1 %cmp14.us, label %cond.end21.us, label %cond.false18.us
if.end6.us: ; preds = %if.end.us
%6 = load i32* @f, align 4
%conv7.us = trunc i32 %6 to i16
%tobool11.us = icmp eq i16 %conv7.us, 0
br i1 %tobool11.us, label %cond.false18.us, label %land.lhs.true12.us
if.end.us: ; preds = %cond.end.us, %if.then.us
br i1 %tobool4, label %if.end6.us, label %for.cond1.preheader
if.then.us: ; preds = %cond.end.us
store i32 0, i32* @f, align 4
br label %if.end.us
cond.end.us: ; preds = %cond.end21.us, %for.cond1.preheader.split.us
%j.1.us = phi i32 [ %conv24.us, %cond.end21.us ], [ %j.073, %for.cond1.preheader.split.us ]
store i32 %conv, i32* @h, align 4
br i1 %cmp, label %if.then.us, label %if.end.us
for.cond1.preheader.split.for.cond1.preheader.split.split_crit_edge: ; preds = %for.cond1.preheader.for.cond1.preheader.split_crit_edge
br i1 %tobool4, label %if.end6.us65, label %for.cond25.loopexit.us-lcssa.us-lcssa
cond.false18.us40: ; preds = %if.end.us50
%7 = load i32* @f, align 4
%sext = shl i32 %7, 16
%phitmp = ashr exact i32 %sext, 16
br label %if.end.us50
if.end.us50: ; preds = %cond.false18.us40, %for.cond1.preheader.for.cond1.preheader.split_crit_edge
%j.1.us36 = phi i32 [ %j.073, %for.cond1.preheader.for.cond1.preheader.split_crit_edge ], [ %phitmp, %cond.false18.us40 ]
store i32 0, i32* @h, align 4
br i1 %tobool4, label %cond.false18.us40, label %for.cond1.preheader
if.end6.us65: ; preds = %if.end6.us65, %for.cond1.preheader.split.for.cond1.preheader.split.split_crit_edge
store i32 0, i32* @h, align 4
br label %if.end6.us65
for.cond25.loopexit.us-lcssa.us-lcssa: ; preds = %for.cond1.preheader.split.for.cond1.preheader.split.split_crit_edge
store i32 0, i32* @h, align 4
br label %for.cond1.preheader
for.end32: ; preds = %entry
ret void
}