Fix crash in arm conditional expression code generation.

Fix crash in arm conditional expression code generation.

Committed: http://code.google.com/p/v8/source/detail?r=2399

[Erik Corry, 2009-07-08 19:39:35]

LGTM

[Mads Ager (chromium), 2009-07-08 19:40:30]

I'll work on generating a regression test case.  This crashes the nytimes.com
webpage when using the arm codegenerator.

[Kevin Millikin (Chromium), 2009-07-09 01:20:31]

This issue is pretty minor.  It only comes up when the condition is
unconditionally true.

I'm not sure how much that comes up on ARM where we don't do compile-time
constant folding yet.  My guess is it's only the optimization "typeof(blah) !=
string" where the string is not one returned by typeof.

http://codereview.chromium.org/155234/diff/1/2
File src/arm/codegen-arm.cc (right):

http://codereview.chromium.org/155234/diff/1/2#newcode2434
Line 2434: if (frame_ != NULL) {
You only need to jump around the else part if you are going to emit it.  You
could write:

if (else_.is_linked()) {
  JumpTarget exit;
  if (has_valid_frame()) exit.Jump();
  LoadAndSpill(node->else_expression(), typeof_state());
  if (exit.is_linked()) exit.Bind();
}

[Mads Ager (chromium), 2009-07-09 04:11:08]

http://codereview.chromium.org/155234/diff/1/2
File src/arm/codegen-arm.cc (right):

http://codereview.chromium.org/155234/diff/1/2#newcode2434
Line 2434: if (frame_ != NULL) {
On 2009/07/09 01:20:31, Kevin Millikin wrote:
> You only need to jump around the else part if you are going to emit it.  You
> could write:
> 
> if (else_.is_linked()) {
>   JumpTarget exit;
>   if (has_valid_frame()) exit.Jump();
>   LoadAndSpill(node->else_expression(), typeof_state());
>   if (exit.is_linked()) exit.Bind();
> }

Done.  I left the binding of the else_ JumpTarget in there though.  :-)