Don't spill dead def.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51305 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/LiveIntervalAnalysis.cpp b/lib/CodeGen/LiveIntervalAnalysis.cpp
index 8b25344b4771f98cfe4030acca773cb1ddc26d25..2558b09ad60f124b9c1dc460f0cd3332893cfac1 100644 (file)
--- a/lib/CodeGen/LiveIntervalAnalysis.cpp
+++ b/lib/CodeGen/LiveIntervalAnalysis.cpp
@@ -1562,7 +1562,9 @@ addIntervalsForSpills(const LiveInterval &li,
         if (!Folded) {
           LiveRange *LR = &nI.ranges[nI.ranges.size()-1];
           bool isKill = LR->end == getStoreIndex(index);
-          vrm.addSpillPoint(VReg, isKill, MI);
+          if (!MI->registerDefIsDead(nI.reg))
+            // No need to spill a dead def.
+            vrm.addSpillPoint(VReg, isKill, MI);
           if (isKill)
             AddedKill.insert(&nI);
         }

diff --git a/test/CodeGen/ARM/2008-05-19-LiveIntervalsBug.ll b/test/CodeGen/ARM/2008-05-19-LiveIntervalsBug.ll
new file mode 100644 (file)
index 0000000..035af08
--- /dev/null
+++ b/test/CodeGen/ARM/2008-05-19-LiveIntervalsBug.ll
@@ -0,0 +1,55 @@
+; RUN: llvm-as < %s | llc -mtriple=arm-apple-darwin
+
+       %struct.BiContextType = type { i16, i8, i32 }
+       %struct.Bitstream = type { i32, i32, i8, i32, i32, i8, i8, i32, i32, i8*, i32 }
+       %struct.DataPartition = type { %struct.Bitstream*, %struct.EncodingEnvironment, %struct.EncodingEnvironment }
+       %struct.DecRefPicMarking_t = type { i32, i32, i32, i32, i32, %struct.DecRefPicMarking_t* }
+       %struct.EncodingEnvironment = type { i32, i32, i32, i32, i32, i8*, i32*, i32, i32 }
+       %struct.ImageParameters = type { i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, float, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i8**, i8**, i32, i32***, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [9 x [16 x [16 x i16]]], [5 x [16 x [16 x i16]]], [9 x [8 x [8 x i16]]], [2 x [4 x [16 x [16 x i16]]]], [16 x [16 x i16]], [16 x [16 x i32]], i32****, i32***, i32***, i32***, i32****, i32****, %struct.Picture*, %struct.Slice*, %struct.Macroblock*, i32*, i32*, i32, i32, i32, i32, [4 x [4 x i32]], i32, i32, i32, i32, i32, double, i32, i32, i32, i32, i16******, i16******, i16******, i16******, [15 x i16], i32, i32, i32, i32, i32, i32, i32, i32, [6 x [32 x i32]], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [1 x i32], i32, i32, [2 x i32], i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, %struct.DecRefPicMarking_t*, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, double**, double***, i32***, double**, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, [3 x [2 x i32]], [2 x i32], i32, i32, i16, i32, i32, i32, i32, i32 }
+       %struct.Macroblock = type { i32, i32, i32, [2 x i32], i32, [8 x i32], %struct.Macroblock*, %struct.Macroblock*, i32, [2 x [4 x [4 x [2 x i32]]]], [16 x i8], [16 x i8], i32, i64, [4 x i32], [4 x i32], i64, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i32, i16, double, i32, i32, i32, i32, i32, i32, i32, i32, i32 }
+       %struct.MotionInfoContexts = type { [3 x [11 x %struct.BiContextType]], [2 x [9 x %struct.BiContextType]], [2 x [10 x %struct.BiContextType]], [2 x [6 x %struct.BiContextType]], [4 x %struct.BiContextType], [4 x %struct.BiContextType], [3 x %struct.BiContextType] }
+       %struct.Picture = type { i32, i32, [100 x %struct.Slice*], i32, float, float, float }
+       %struct.Slice = type { i32, i32, i32, i32, i32, i32, %struct.DataPartition*, %struct.MotionInfoContexts*, %struct.TextureInfoContexts*, i32, i32*, i32*, i32*, i32, i32*, i32*, i32*, i32 (i32)*, [3 x [2 x i32]] }
+       %struct.TextureInfoContexts = type { [2 x %struct.BiContextType], [4 x %struct.BiContextType], [3 x [4 x %struct.BiContextType]], [10 x [4 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]], [10 x [5 x %struct.BiContextType]], [10 x [5 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]], [10 x [15 x %struct.BiContextType]] }
+@images = external global %struct.ImageParameters              ; <%struct.ImageParameters*> [#uses=2]
+
+declare i8* @calloc(i32, i32)
+
+define fastcc void @init_global_buffers() nounwind {
+entry:
+       %tmp50.i.i = mul i32 0, 0               ; <i32> [#uses=2]
+       br i1 false, label %init_orig_buffers.exit, label %cond_true.i29
+
+cond_true.i29:         ; preds = %entry
+       %tmp17.i = load i32* getelementptr (%struct.ImageParameters* @images, i32 0, i32 20), align 8           ; <i32> [#uses=1]
+       %tmp20.i27 = load i32* getelementptr (%struct.ImageParameters* @images, i32 0, i32 16), align 8         ; <i32> [#uses=1]
+       %tmp8.i.i = select i1 false, i32 1, i32 0               ; <i32> [#uses=1]
+       br label %bb.i8.us.i
+
+bb.i8.us.i:            ; preds = %get_mem2Dpel.exit.i.us.i, %cond_true.i29
+       %j.04.i.us.i = phi i32 [ %indvar.next39.i, %get_mem2Dpel.exit.i.us.i ], [ 0, %cond_true.i29 ]           ; <i32> [#uses=2]
+       %tmp13.i.us.i = getelementptr i16*** null, i32 %j.04.i.us.i             ; <i16***> [#uses=0]
+       %tmp15.i.i.us.i = tail call i8* @calloc( i32 0, i32 2 )         ; <i8*> [#uses=0]
+       store i16* null, i16** null, align 4
+       br label %bb.i.i.us.i
+
+get_mem2Dpel.exit.i.us.i:              ; preds = %bb.i.i.us.i
+       %indvar.next39.i = add i32 %j.04.i.us.i, 1              ; <i32> [#uses=2]
+       %exitcond40.i = icmp eq i32 %indvar.next39.i, 2         ; <i1> [#uses=1]
+       br i1 %exitcond40.i, label %get_mem3Dpel.exit.split.i, label %bb.i8.us.i
+
+bb.i.i.us.i:           ; preds = %bb.i.i.us.i, %bb.i8.us.i
+       %exitcond.i = icmp eq i32 0, %tmp8.i.i          ; <i1> [#uses=1]
+       br i1 %exitcond.i, label %get_mem2Dpel.exit.i.us.i, label %bb.i.i.us.i
+
+get_mem3Dpel.exit.split.i:             ; preds = %get_mem2Dpel.exit.i.us.i
+       %tmp30.i.i = shl i32 %tmp17.i, 2                ; <i32> [#uses=1]
+       %tmp31.i.i = mul i32 %tmp30.i.i, %tmp20.i27             ; <i32> [#uses=1]
+       %tmp23.i31 = add i32 %tmp31.i.i, %tmp50.i.i             ; <i32> [#uses=1]
+       br label %init_orig_buffers.exit
+
+init_orig_buffers.exit:                ; preds = %get_mem3Dpel.exit.split.i, %entry
+       %memory_size.0.i = phi i32 [ %tmp23.i31, %get_mem3Dpel.exit.split.i ], [ %tmp50.i.i, %entry ]           ; <i32> [#uses=1]
+       %tmp41 = add i32 0, %memory_size.0.i            ; <i32> [#uses=0]
+       unreachable
+}