We're basically trading undefined behavior for implementation defined
behavior, which should be OK for UBSan. :-) The generated code should
be identical, at least I checked that for GCC 4.6.3 on x64.

BUG=377790
LOG=y
R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/332733002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21828 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/321373002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21827 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/324913002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21826 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

The at register is no longer in usage, so changed it to "scratch".

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/335753003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21825 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Initialize scratch register for all possible code paths.

TEST=mjsunit/compiler/division-by-constant.js
BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/333713002

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21822 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=machenbach@chromium.org

Review URL: https://codereview.chromium.org/329303004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21821 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=rossberg@chromium.org
BUG=http://code.google.com/p/v8/issues/detail?id=2735
LOG=N

Review URL: https://codereview.chromium.org/332663004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21820 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=none
R=dcarney@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/328993003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21819 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Hydrogen attempts to force representation changes on certain operations in order
to deoptimise on the change rather than the operation. However, these forced
changes are often unnecessary on 64-bit platforms, and cause poor code
generation, so this patch makes some of them conditional on whether it's
possible for deoptimisation to occur in the change.

On ARM64, this prevents sequences like:
                  ;;; <@46,#89> smi-tag
0x7ff282c7f050   144  lsl x4, x4, #32
                  ;;; <@48,#90> smi-untag
0x7ff282c7f054   148  asr x5, x4, #32
                  ;;; <@50,#31> mul-const-i-s
0x7ff282c7f058   152  lsl w6, w5, #3

BUG=
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/303263010

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21818 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Review URL: https://codereview.chromium.org/332783002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21817 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This avoids endless IC patching cycles between "normal" and "nonexistent" handlers when objects having and not having the property are seen alternatingly

R=yangguo@chromium.org

Review URL: https://codereview.chromium.org/328353002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21816 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TEST=mjsunit/regress/regress-3380
BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/329223006

Patch from Balazs Kilvady <kilvadyb@homejinni.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21815 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
R=ishell@chromium.org

Review URL: https://codereview.chromium.org/321543004

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21814 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Port r21781 (4869c528)

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/336543002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21813 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Due to mirror-object test failure (although I'm pretty sure I was framed)

R=mstarzinger@chromium.org
TBR=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/328333002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21812 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=dcarney@chromium.org

Review URL: https://codereview.chromium.org/330023002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21811 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

All places that use OS::Allocate either CHECK() that the result is non-NULL,
or use a reasonable fallback if they can't mmap memory.

BUG=none
R=mstarzinger@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/326323002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21810 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=mstarzinger@chromium.org

BUG=

Review URL: https://codereview.chromium.org/333503005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21809 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
R=ulan@chromium.org

Review URL: https://codereview.chromium.org/324403008

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21808 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=danno@chromium.org

BUG=chromium:381910

Review URL: https://codereview.chromium.org/336483002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21807 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Sign extend the dehoisted key at the definition point for x64 port only; for x32 port, we need to sign extend the dehoisted key at the use points.

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/328553005

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21806 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Blink needs v8::Promise::Then to implement ScriptPromise::then.
Blink-side CL: https://codereview.chromium.org/316453002

BUG=371288
LOG=Y
R=rossberg@chromium.org

Review URL: https://codereview.chromium.org/314553002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21805 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

About a 32% boost.

Before - 5:31

Richards: 84.5
DeltaBlue: 128
Crypto: 65.3
RayTrace: 203
EarleyBoyer: 149
RegExp: 23.4
Splay: 121
NavierStokes: 98.9
----
Score (version 7): 93.8

After - 4:10

Richards: 107
DeltaBlue: 175
Crypto: 93.9
RayTrace: 258
EarleyBoyer: 186
RegExp: 32.7
Splay: 165
NavierStokes: 124
----
Score (version 7): 124

R=jacob.bramley@arm.com, svenpanne@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=21448

Review URL: https://codereview.chromium.org/213943002

Patch from Fritz Koenig <frkoenig@google.com>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21804 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This CL tickled an unrelated arm64 bug which was is fixed separately.

The MIPS port (originally landed 21784) is also included.

TBR=verwaest@chromium.org

Review URL: https://codereview.chromium.org/331633002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21803 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/314673002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21802 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

TBR=haitao.feng@intel.com

Review URL: https://codereview.chromium.org/325343003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21801 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/335473003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21800 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/334573003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21799 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=ulan@chromium.org

Review URL: https://codereview.chromium.org/330593003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21798 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=arv@chromium.org, rossberg@chromium.org
BUG=

Review URL: https://codereview.chromium.org/328093002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21797 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

This reverts commit r21784 as the original CL also got reverted.

BUG=
TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/329973002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21794 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

BUG=

Review URL: https://codereview.chromium.org/294073002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21793 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Due to lingering arm64 failures in Test262

TBR=mstarzinger@chromium.org

Review URL: https://codereview.chromium.org/332663003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21790 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=v8:3387
LOG=y
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/329963002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21789 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=none
R=marja@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/323303002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21788 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/323413002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21785 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

Port r21781 (4869c528)

BUG=
R=plind44@gmail.com

Review URL: https://codereview.chromium.org/327373002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21784 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
TBR=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/330573002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21783 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

BUG=
TBR=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/330563002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21782 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

R=verwaest@chromium.org

Review URL: https://codereview.chromium.org/57123002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@21781 ce2b1a6d-e550-0410-aec6-3dcde31c8c00