[llvm-commits] CVS: llvm/lib/CodeGen/LiveIntervalAnalysis.cpp

[Evan Cheng]

Changes in directory llvm/lib/CodeGen:

LiveIntervalAnalysis.cpp updated: 1.228 -> 1.229
---
Log message:

Fix for PR1279: http://llvm.org/PR1279 . Dead def has a live interval of length 1. Copy coalescing should
not violate that.

---
Diffs of the changes:  (+5 -3)

 LiveIntervalAnalysis.cpp |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)


Index: llvm/lib/CodeGen/LiveIntervalAnalysis.cpp
diff -u llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.228 llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.229
--- llvm/lib/CodeGen/LiveIntervalAnalysis.cpp:1.228	Mon Mar 26 17:40:42 2007
+++ llvm/lib/CodeGen/LiveIntervalAnalysis.cpp	Tue Mar 27 20:30:37 2007
@@ -935,9 +935,9 @@
     // The instruction which defines the src is only truly dead if there are
     // no intermediate uses and there isn't a use beyond the copy.
     // FIXME: find the last use, mark is kill and shorten the live range.
-    if (SrcEnd > getDefIndex(CopyIdx))
+    if (SrcEnd > getDefIndex(CopyIdx)) {
       isDead = false;
-    else {
+    } else {
       MachineOperand *MOU;
       MachineInstr *LastUse= lastRegisterUse(repSrcReg, SrcStart, CopyIdx, MOU);
       if (LastUse) {
@@ -947,7 +947,9 @@
         isShorten = true;
         RemoveStart = getDefIndex(getInstructionIndex(LastUse));
         RemoveEnd   = SrcEnd;
-      }
+      } else if (RemoveStart > 0)
+        // A dead def should have a single cycle interval.
+        ++RemoveStart;
     }
   }