Stack Coloring: Handle the case where END markers come before BEGIN markers properly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163530 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/CodeGen/StackColoring.cpp b/lib/CodeGen/StackColoring.cpp
index 462a134ace3156da6c0fd15128da8f1789820b90..927ecef17160ba8971397e156acf4bc6d520d049 100644 (file)
--- a/lib/CodeGen/StackColoring.cpp
+++ b/lib/CodeGen/StackColoring.cpp
@@ -315,6 +315,18 @@ void StackColoring::calculateLocalLiveness() {
       LocalLiveOut.reset(BlockLiveness[BB].End);
       LocalLiveIn.reset(BlockLiveness[BB].Begin);
 
+      // If we have both BEGIN and END markers in the same basic block then
+      // we know that the BEGIN marker comes after the END, because we already
+      // handle the case where the BEGIN comes before the END when collecting
+      // the markers (and building the BEGIN/END vectore).
+      // Want to enable the LIVE_IN and LIVE_OUT of slots that have both
+      // BEGIN and END because it means that the value lives before and after
+      // this basic block.
+      BitVector LocalEndBegin = BlockLiveness[BB].End;
+      LocalEndBegin &= BlockLiveness[BB].Begin;
+      LocalLiveIn |= LocalEndBegin;
+      LocalLiveOut |= LocalEndBegin;
+
       if (LocalLiveIn.test(BlockLiveness[BB].LiveIn)) {
         changed = true;
         BlockLiveness[BB].LiveIn |= LocalLiveIn;

diff --git a/test/CodeGen/X86/StackColoring.ll b/test/CodeGen/X86/StackColoring.ll
index 6ef3b3cd023223d4da6b71ca9fe38e1612658d7c..0f36ce29b9a8f4993835866bd459a77d889fb1ab 100644 (file)
--- a/test/CodeGen/X86/StackColoring.ll
+++ b/test/CodeGen/X86/StackColoring.ll
@@ -325,6 +325,33 @@ entry:
   ret void
 }
 
+
+;YESCOLOR: subq  $272, %rsp
+;NOCOLOR: subq  $272, %rsp
+
+define i32 @myCall_end_before_begin(i32 %in, i1 %d) {
+entry:
+  %a = alloca [17 x i8*], align 8
+  %a2 = alloca [16 x i8*], align 8
+  %b = bitcast [17 x i8*]* %a to i8*
+  %b2 = bitcast [16 x i8*]* %a2 to i8*
+  %t1 = call i32 @foo(i32 %in, i8* %b)
+  %t2 = call i32 @foo(i32 %in, i8* %b)
+  call void @llvm.lifetime.end(i64 -1, i8* %b)
+  call void @llvm.lifetime.start(i64 -1, i8* %b)
+  br i1 %d, label %bb2, label %bb3
+bb2:
+  call void @llvm.lifetime.start(i64 -1, i8* %b2)
+  %t3 = call i32 @foo(i32 %in, i8* %b2)
+  %t4 = call i32 @foo(i32 %in, i8* %b2)
+  %t5 = add i32 %t1, %t2
+  %t6 = add i32 %t3, %t4
+  %t7 = add i32 %t5, %t6
+  ret i32 %t7
+bb3:
+  ret i32 0
+}
+
 declare void @bar([100 x i32]* , [100 x i32]*) nounwind
 
 declare void @llvm.lifetime.start(i64, i8* nocapture) nounwind