Add more details the --trace-deopt output

src/arm/deoptimizer-arm.cc

Index: src/arm/deoptimizer-arm.cc
===================================================================
--- src/arm/deoptimizer-arm.cc	(revision 7379)
+++ src/arm/deoptimizer-arm.cc	(working copy)
@@ -291,10 +291,18 @@
   for (int i = 0; ok && i < 4; i++) {
     uint32_t input_value = input_->GetFrameSlot(input_offset);
     if (FLAG_trace_osr) {
-      PrintF("    [sp + %d] <- 0x%08x ; [sp + %d] (fixed part)\n",
+      const char* name = "UNKNOWN";
+      switch (i) {

[Kevin Millikin (Chromium), 2011/03/28 09:07:01]

Maybe it would be nicer to use the constants in frames-arm.h.  This bit of the
frame is uninterpreted by OSR, so it doesn't actually matter what "i"
corresponds to.  You could do something like:

for (int i = 1; ok && i >= -2; --i) {
  ...
  if (FLAG_trace_osr) {
    const char* name = "UNKNOWN";
    switch (i * kPointerSize) {
      case StandardFrameConstants::kCallerPCOffset:
        name = "caller's pc";
        break;
      case StandardFrameConstants::kCallerFPOffset:
        name = "caller's fp";
        break;
      case StandardFrameConstants::kContextOffset:
        name = "context";
        break;
      case JavaScriptFrameConstants::kFunctionOffset:
        name = "function";
        break;
    }

[Søren Thygesen Gjesse, 2011/03/28 12:27:29]

Good point, used

  for (int i =  StandardFrameConstants::kCallerPCOffset;
       ok && i >=  StandardFrameConstants::kMarkerOffset;
       i -= kPointerSize) {

for the looping.

[Kevin Millikin (Chromium), 2011/03/28 13:11:40]

Sounds good.

+        case 0: name = "caller's pc"; break;
+        case 1: name = "fp"; break;
+        case 2: name = "context"; break;
+        case 3: name = "function"; break;
+      }
+      PrintF("    [sp + %d] <- 0x%08x ; [sp + %d] (fixed part - %s)\n",
              output_offset,
              input_value,
-             input_offset);
+             input_offset,
+             name);
     }
     output_[0]->SetFrameSlot(output_offset, input_->GetFrameSlot(input_offset));
     input_offset -= kPointerSize;