Initial implementation of fast path operation for bitwise OR.

Initial implementation of fast path operation for bitwise OR.

Support a binary operation (bitwise OR) so long as it's not nested in
the left subexpression.  This ensures that the expression stack never
has height greater than two and so can be kept fully in registers.

The bounded expression stack height and the absence of any side
effects on the fast path allows us to still bailout out to the very
beginning of the function if any of our fast-path checks fail.

Committed: http://code.google.com/p/v8/source/detail?r=3822

[Kevin Millikin (Chromium), 2010-02-09 12:27:43]

I'll put together some dedicated tests as a separate change.

[Mads Ager (chromium), 2010-02-09 13:15:44]

LGTM except for the inobject property load case.

http://codereview.chromium.org/594008/diff/1/2
File src/arm/fast-codegen-arm.cc (right):

http://codereview.chromium.org/594008/diff/1/2#newcode111
src/arm/fast-codegen-arm.cc:111: __ ldr(destination(),
FieldMemOperand(scratch0(), offset));
scratch0() receiver_reg()?

http://codereview.chromium.org/594008/diff/1/7
File src/ia32/fast-codegen-ia32.cc (right):

http://codereview.chromium.org/594008/diff/1/7#newcode115
src/ia32/fast-codegen-ia32.cc:115: __ mov(destination(),
FieldOperand(scratch0(), offset));
scratch0() -> receiver_reg()?

http://codereview.chromium.org/594008/diff/1/8
File src/x64/fast-codegen-x64.cc (right):

http://codereview.chromium.org/594008/diff/1/8#newcode114
src/x64/fast-codegen-x64.cc:114: __ movq(destination(), FieldOperand(scratch0(),
offset));
scratch0() -> receiver_reg()?

[Kevin Millikin (Chromium), 2010-02-09 13:26:07]

http://codereview.chromium.org/594008/diff/1/2
File src/arm/fast-codegen-arm.cc (right):

http://codereview.chromium.org/594008/diff/1/2#newcode111
src/arm/fast-codegen-arm.cc:111: __ ldr(destination(),
FieldMemOperand(scratch0(), offset));
On 2010/02/09 13:15:44, Mads Ager wrote:
> scratch0() receiver_reg()?

Yes, thank you.