Add more generic version of reloc info padding to ensure enough space for rel...

Add more generic version of reloc info padding to ensure enough space for reloc patching during deoptimization (fixes issue 1174).

The old version only added extra space when we did indirect calls, but
the problem remains the same with normal calls that can be represented
as a single byte. When doing patching each call will always be at
least 2 bytes long because we use RUNTIME_ENTY as the reloc mode.



Committed: http://code.google.com/p/v8/source/detail?r=6894

[Søren Thygesen Gjesse, 2011-02-21 13:27:20]

LGTM, however I am wondering if it wouldn't be better to collect what we need
instead of the deltas where we generate to little?

  AddToMinRelocSizeForDeoptimization

  min_reloc_size_for_deoptimization_

The call AddToMinRelocSizeForDeoptimization at all places where deopt will have
to write new reloc info.

That will make it more clear what is happening, and we don't need to do padding
if other reloc info provides the space we need as we end up wiht a min size for
the reloc info required for deopt.

http://codereview.chromium.org/6541053/diff/2002/src/assembler.h
File src/assembler.h (right):

http://codereview.chromium.org/6541053/diff/2002/src/assembler.h#newcode187
src/assembler.h:187: // The size of a comment is equal to tree bytes for the
extra tagged pc +
tree -> three

http://codereview.chromium.org/6541053/diff/2002/src/ia32/lithium-codegen-ia3...
File src/ia32/lithium-codegen-ia32.cc (right):

http://codereview.chromium.org/6541053/diff/2002/src/ia32/lithium-codegen-ia3...
src/ia32/lithium-codegen-ia32.cc:396: RecordPosition(pointers->position());
Move this comment and code to after the '__ call'?

http://codereview.chromium.org/6541053/diff/2002/src/ia32/lithium-codegen-ia32.h
File src/ia32/lithium-codegen-ia32.h (right):

http://codereview.chromium.org/6541053/diff/2002/src/ia32/lithium-codegen-ia3...
src/ia32/lithium-codegen-ia32.h:106: void AddRelocPadding(int count) {
reloc_padding_count_ += count; }
AddRelocPadding -> AddRelocPaddingForDeoptimization

http://codereview.chromium.org/6541053/diff/2002/src/ia32/lithium-codegen-ia3...
src/ia32/lithium-codegen-ia32.h:259: int reloc_padding_count_;
reloc_padding_count_ -> reloc_padding_count_for_deoptimization_

[Rico, 2011-02-22 11:48:19]

Could you have another look, I changed this actually calculate how much space is
actually needed.

[Søren Thygesen Gjesse, 2011-02-22 11:58:33]

LGTM

http://codereview.chromium.org/6541053/diff/6003/src/ia32/lithium-codegen-ia32.h
File src/ia32/lithium-codegen-ia32.h (right):

http://codereview.chromium.org/6541053/diff/6003/src/ia32/lithium-codegen-ia3...
src/ia32/lithium-codegen-ia32.h:106: void EnsureRelocSpaceForDeoptimization() {
Do we want this in the .h file (I guess we have no lithium-codegen-ia32-inl.h)?

[Rico, 2011-02-22 12:06:10]

http://codereview.chromium.org/6541053/diff/6003/src/ia32/lithium-codegen-ia32.h
File src/ia32/lithium-codegen-ia32.h (right):

http://codereview.chromium.org/6541053/diff/6003/src/ia32/lithium-codegen-ia3...
src/ia32/lithium-codegen-ia32.h:106: void EnsureRelocSpaceForDeoptimization() {
On 2011/02/22 11:58:33, Søren Gjesse wrote:
> Do we want this in the .h file (I guess we have no
lithium-codegen-ia32-inl.h)?

Moved to the cc file