Patch to enhance the source code line information for profiler.

src/ia32/lithium-codegen-ia32.cc

Index: src/ia32/lithium-codegen-ia32.cc
===================================================================
--- src/ia32/lithium-codegen-ia32.cc	(revision 15925)
+++ src/ia32/lithium-codegen-ia32.cc	(working copy)
@@ -350,6 +350,9 @@
 
     if (!CpuFeatures::IsSupported(SSE2)) FlushX87StackIfNecessary(instr);
 
+    int pos = instr->position();
+    if (pos >= 0) RecordPosition(pos);

[danno, 2013/07/29 12:29:01]

In order to optimize the size of the source pos tables, don't output the pos
again if it's the same as the pos for the last instruction.

+
     instr->CompileToNative(this);

[danno, 2013/07/29 12:29:01]

Not that your solution doesn't handle deferred code correctly, which is all
output at the end of a routine. Please take a look at GenerateDeferredCode.

 
     if (!CpuFeatures::IsSupported(SSE2)) {