[llvm-commits] [llvm] r163530 - in /llvm/trunk: lib/CodeGen/StackColoring.cpp test/CodeGen/X86/StackColoring.ll

[Nadav Rotem]

Author: nadav
Date: Mon Sep 10 13:51:09 2012
New Revision: 163530

URL: http://llvm.org/viewvc/llvm-project?rev=163530&view=rev
Log:
Stack Coloring: Handle the case where END markers come before BEGIN markers properly.

Modified:
    llvm/trunk/lib/CodeGen/StackColoring.cpp
    llvm/trunk/test/CodeGen/X86/StackColoring.ll

Modified: llvm/trunk/lib/CodeGen/StackColoring.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/StackColoring.cpp?rev=163530&r1=163529&r2=163530&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/StackColoring.cpp (original)
+++ llvm/trunk/lib/CodeGen/StackColoring.cpp Mon Sep 10 13:51:09 2012
@@ -315,6 +315,18 @@
       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;

Modified: llvm/trunk/test/CodeGen/X86/StackColoring.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/StackColoring.ll?rev=163530&r1=163529&r2=163530&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/StackColoring.ll (original)
+++ llvm/trunk/test/CodeGen/X86/StackColoring.ll Mon Sep 10 13:51:09 2012
@@ -325,6 +325,33 @@
   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