Revert r132245, "Create two BlockInfo entries when a live range is discontinuous through a block."
This commit seems to have broken a darwin 9 tester.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132299 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SplitKit.cpp b/lib/CodeGen/SplitKit.cpp
index ef5650c..53141b5 100644
--- a/lib/CodeGen/SplitKit.cpp
+++ b/lib/CodeGen/SplitKit.cpp
@@ -145,7 +145,7 @@
/// where CurLI is live.
bool SplitAnalysis::calcLiveBlockInfo() {
ThroughBlocks.resize(MF.getNumBlockIDs());
- NumThroughBlocks = NumGapBlocks = 0;
+ NumThroughBlocks = 0;
if (CurLI->empty())
return true;
@@ -164,63 +164,56 @@
SlotIndex Start, Stop;
tie(Start, Stop) = LIS.getSlotIndexes()->getMBBRange(BI.MBB);
- // If the block contains no uses, the range must be live through. At one
- // point, SimpleRegisterCoalescing could create dangling ranges that ended
- // mid-block.
- if (UseI == UseE || *UseI >= Stop) {
- ++NumThroughBlocks;
- ThroughBlocks.set(BI.MBB->getNumber());
- // The range shouldn't end mid-block if there are no uses. This shouldn't
- // happen.
- if (LVI->end < Stop)
- return false;
- } else {
- // This block has uses. Find the first and last uses in the block.
+ // LVI is the first live segment overlapping MBB.
+ BI.LiveIn = LVI->start <= Start;
+ if (!BI.LiveIn)
+ BI.Def = LVI->start;
+
+ // Find the first and last uses in the block.
+ bool Uses = UseI != UseE && *UseI < Stop;
+ if (Uses) {
BI.FirstUse = *UseI;
assert(BI.FirstUse >= Start);
do ++UseI;
while (UseI != UseE && *UseI < Stop);
BI.LastUse = UseI[-1];
assert(BI.LastUse < Stop);
-
- // LVI is the first live segment overlapping MBB.
- BI.LiveIn = LVI->start <= Start;
-
- // Look for gaps in the live range.
- BI.LiveOut = true;
- while (LVI->end < Stop) {
- SlotIndex LastStop = LVI->end;
- if (++LVI == LVE || LVI->start >= Stop) {
- BI.LiveOut = false;
- break;
- }
- if (LastStop < LVI->start) {
- // There is a gap in the live range. Create duplicate entries for the
- // live-in snippet and the live-out snippet.
- ++NumGapBlocks;
-
- // Push the Live-in part.
- BI.LiveThrough = false;
- BI.LiveOut = false;
- UseBlocks.push_back(BI);
- UseBlocks.back().LastUse = LastStop;
-
- // Set up BI for the live-out part.
- BI.LiveIn = false;
- BI.LiveOut = true;
- BI.FirstUse = LVI->start;
- }
- }
-
- // Don't set LiveThrough when the block has a gap.
- BI.LiveThrough = BI.LiveIn && BI.LiveOut;
- UseBlocks.push_back(BI);
-
- // LVI is now at LVE or LVI->end >= Stop.
- if (LVI == LVE)
- break;
}
+ // Look for gaps in the live range.
+ bool hasGap = false;
+ BI.LiveOut = true;
+ while (LVI->end < Stop) {
+ SlotIndex LastStop = LVI->end;
+ if (++LVI == LVE || LVI->start >= Stop) {
+ BI.Kill = LastStop;
+ BI.LiveOut = false;
+ break;
+ }
+ if (LastStop < LVI->start) {
+ hasGap = true;
+ BI.Kill = LastStop;
+ BI.Def = LVI->start;
+ }
+ }
+
+ // Don't set LiveThrough when the block has a gap.
+ BI.LiveThrough = !hasGap && BI.LiveIn && BI.LiveOut;
+ if (Uses)
+ UseBlocks.push_back(BI);
+ else {
+ ++NumThroughBlocks;
+ ThroughBlocks.set(BI.MBB->getNumber());
+ }
+ // FIXME: This should never happen. The live range stops or starts without a
+ // corresponding use. An earlier pass did something wrong.
+ if (!BI.LiveThrough && !Uses)
+ return false;
+
+ // LVI is now at LVE or LVI->end >= Stop.
+ if (LVI == LVE)
+ break;
+
// Live segment ends exactly at Stop. Move to the next segment.
if (LVI->end == Stop && ++LVI == LVE)
break;