X64 Crankshaft: Add DoPower to lithium compiler on x64 platform.

X64 Crankshaft: Add DoPower to lithium compiler on x64 platform.

Committed: http://code.google.com/p/v8/source/detail?r=6980

[Rico, 2011-02-28 19:18:34]

LGTM

http://codereview.chromium.org/6592038/diff/1/src/x64/lithium-codegen-x64.cc
File src/x64/lithium-codegen-x64.cc (right):

http://codereview.chromium.org/6592038/diff/1/src/x64/lithium-codegen-x64.cc#...
src/x64/lithium-codegen-x64.cc:2466: DoubleRegister left_reg =
ToDoubleRegister(left);
I don't think we use DoubleRegister anywhere else do we, normally we use
XMMRegister. I was not even aware that we had a typedef of this

http://codereview.chromium.org/6592038/diff/1/src/x64/lithium-codegen-x64.cc#...
src/x64/lithium-codegen-x64.cc:2475: if (!right_reg.is(xmm1)) {
We know that right is in xmm2, you explicitly request that in lithium-x64

http://codereview.chromium.org/6592038/diff/1/src/x64/lithium-codegen-x64.cc#...
src/x64/lithium-codegen-x64.cc:2484: if (!right_reg.is(rdi)) {
We know that right is in rax, you explicitly request this in lithium-x64

http://codereview.chromium.org/6592038/diff/1/src/x64/lithium-x64.cc
File src/x64/lithium-x64.cc (right):

http://codereview.chromium.org/6592038/diff/1/src/x64/lithium-x64.cc#newcode1450
src/x64/lithium-x64.cc:1450: CAN_DEOPTIMIZE_EAGERLY);
I do not see why we request right to be in xmm2 and rax when we need them in rdi
and xmm1. In addition, is there any reason why we require the result to be in
xmm3?

[William Hesse, 2011-03-01 09:30:45]

Comments all addressed.  Added Win64 use of rdx instead of rdi for first integer
argument.