From 25f34a30d66e33381a023d97d72ce44ded2c7f72 Mon Sep 17 00:00:00 2001
From: Evan Cheng <evan.cheng@apple.com>
Date: Mon, 15 Sep 2008 06:28:41 +0000
Subject: [PATCH] Correctly update kill infos after extending a live range and
 merge 2 val#'s; fix 56165 - do not mark val# copy field if the copy does not
 define the val#.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56199 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/SimpleRegisterCoalescing.cpp   | 11 +++++---
 test/CodeGen/ARM/2008-09-14-CoaleserBug.ll | 29 ++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 test/CodeGen/ARM/2008-09-14-CoaleserBug.ll

diff --git a/lib/CodeGen/SimpleRegisterCoalescing.cpp b/lib/CodeGen/SimpleRegisterCoalescing.cpp
index 0a1419ce810..e06eb161c08 100644
--- a/lib/CodeGen/SimpleRegisterCoalescing.cpp
+++ b/lib/CodeGen/SimpleRegisterCoalescing.cpp
@@ -182,16 +182,20 @@ bool SimpleRegisterCoalescing::AdjustCopiesBackFrom(LiveInterval &IntA,
   }
 
   // Okay, merge "B1" into the same value number as "B0".
-  if (BValNo != ValLR->valno)
+  if (BValNo != ValLR->valno) {
+    IntB.addKills(ValLR->valno, BValNo->kills);
     IntB.MergeValueNumberInto(BValNo, ValLR->valno);
+  }
   DOUT << "   result = "; IntB.print(DOUT, tri_);
   DOUT << "\n";
 
   // If the source instruction was killing the source register before the
   // merge, unset the isKill marker given the live range has been extended.
   int UIdx = ValLREndInst->findRegisterUseOperandIdx(IntB.reg, true);
-  if (UIdx != -1)
+  if (UIdx != -1) {
     ValLREndInst->getOperand(UIdx).setIsKill(false);
+    IntB.removeKill(ValLR->valno, FillerStart);
+  }
 
   ++numExtends;
   return true;
@@ -568,7 +572,8 @@ SimpleRegisterCoalescing::UpdateRegDefsUses(unsigned SrcReg, unsigned DstReg,
       LiveInterval &LI = li_->getInterval(CopyDstReg);
       unsigned DefIdx = li_->getDefIndex(li_->getInstructionIndex(UseMI));
       const LiveRange *DLR = LI.getLiveRangeContaining(DefIdx);
-      DLR->valno->copy = UseMI;
+      if (DLR->valno->def == DefIdx)
+        DLR->valno->copy = UseMI;
     }
   }
 }
diff --git a/test/CodeGen/ARM/2008-09-14-CoaleserBug.ll b/test/CodeGen/ARM/2008-09-14-CoaleserBug.ll
new file mode 100644
index 00000000000..c601b90e071
--- /dev/null
+++ b/test/CodeGen/ARM/2008-09-14-CoaleserBug.ll
@@ -0,0 +1,29 @@
+; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin
+
+@"\01LC1" = external constant [288 x i8]		; <[288 x i8]*> [#uses=1]
+
+declare void @llvm.memcpy.i32(i8*, i8*, i32, i32) nounwind
+
+define i32 @main(i32 %argc, i8** %argv) nounwind {
+entry:
+	br label %bb.i
+
+bb.i:		; preds = %bb.i, %entry
+	%i.01.i = phi i32 [ 0, %entry ], [ %indvar.next52, %bb.i ]		; <i32> [#uses=1]
+	%indvar.next52 = add i32 %i.01.i, 1		; <i32> [#uses=2]
+	%exitcond53 = icmp eq i32 %indvar.next52, 15		; <i1> [#uses=1]
+	br i1 %exitcond53, label %bb.i33.loopexit, label %bb.i
+
+bb.i33.loopexit:		; preds = %bb.i
+	%0 = malloc [347 x i8]		; <[347 x i8]*> [#uses=2]
+	%.sub = getelementptr [347 x i8]* %0, i32 0, i32 0		; <i8*> [#uses=1]
+	call void @llvm.memcpy.i32( i8* %.sub, i8* getelementptr ([288 x i8]* @"\01LC1", i32 0, i32 0), i32 287, i32 1 ) nounwind
+	br label %bb.i28
+
+bb.i28:		; preds = %bb.i28, %bb.i33.loopexit
+	br i1 false, label %repeat_fasta.exit, label %bb.i28
+
+repeat_fasta.exit:		; preds = %bb.i28
+	free [347 x i8]* %0
+	unreachable
+}