PR11868. The previous loop in LiveIntervals::join would sometimes fall over if

more than two adjacent ranges needed to be merged. The new version should be
able to handle an arbitrary sequence of adjancent ranges.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149588 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Lang Hames 2012-02-02 05:37:34 +00:00
parent 3f5b107a4b
commit 02e08d5b4d
2 changed files with 38 additions and 11 deletions

View File

@ -389,29 +389,30 @@ void LiveInterval::join(LiveInterval &Other,
// now.
if (MustMapCurValNos) {
// Map the first live range.
iterator OutIt = begin();
OutIt->valno = NewVNInfo[LHSValNoAssignments[OutIt->valno->id]];
++OutIt;
for (iterator I = OutIt, E = end(); I != E; ++I) {
OutIt->valno = NewVNInfo[LHSValNoAssignments[I->valno->id]];
for (iterator I = next(OutIt), E = end(); I != E; ++I) {
VNInfo* nextValNo = NewVNInfo[LHSValNoAssignments[I->valno->id]];
assert(nextValNo != 0 && "Huh?");
// If this live range has the same value # as its immediate predecessor,
// and if they are neighbors, remove one LiveRange. This happens when we
// have [0,3:0)[4,7:1) and map 0/1 onto the same value #.
if (OutIt->valno == (OutIt-1)->valno && (OutIt-1)->end == OutIt->start) {
(OutIt-1)->end = OutIt->end;
// have [0,4:0)[4,7:1) and map 0/1 onto the same value #.
if (OutIt->valno == nextValNo && OutIt->end == I->start) {
OutIt->end = I->end;
} else {
if (I != OutIt) {
// Didn't merge. Move OutIt to the next interval,
++OutIt;
OutIt->valno = nextValNo;
if (OutIt != I) {
OutIt->start = I->start;
OutIt->end = I->end;
}
// Didn't merge, on to the next one.
++OutIt;
}
}
// If we merge some live ranges, chop off the end.
++OutIt;
ranges.erase(OutIt, end());
}

View File

@ -0,0 +1,26 @@
; RUN: llc -verify-coalescing < %s
; PR11868
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:64:128-a0:0:64-n32-S64"
target triple = "armv7-none-linux-gnueabi"
%0 = type { <4 x float> }
%1 = type { <4 x float> }
@foo = external global %0, align 16
define arm_aapcs_vfpcc void @bar(float, i1 zeroext, i1 zeroext) nounwind {
%4 = load <4 x float>* getelementptr inbounds (%0* @foo, i32 0, i32 0), align 16
%5 = extractelement <4 x float> %4, i32 0
%6 = extractelement <4 x float> %4, i32 1
%7 = extractelement <4 x float> %4, i32 2
%8 = insertelement <4 x float> undef, float %5, i32 0
%9 = insertelement <4 x float> %8, float %6, i32 1
%10 = insertelement <4 x float> %9, float %7, i32 2
%11 = insertelement <4 x float> %10, float 0.000000e+00, i32 3
store <4 x float> %11, <4 x float>* undef, align 16
call arm_aapcs_vfpcc void @baz(%1* undef, float 0.000000e+00) nounwind
ret void
}
declare arm_aapcs_vfpcc void @baz(%1*, float)