Implement the Oilpan pushAllRegisters on MIPS64

Implement the Oilpan pushAllRegisters on MIPS64

Add missing implementation of pushAllRegisters for MIPS64.

BUG=400684
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180461

[petarj, 2014-08-15 13:32:59]

PTAL.

[haraken, 2014-08-15 14:43:21]

Just a drive-by:

https://codereview.chromium.org/476143002/diff/20001/Source/platform/heap/asm...
File Source/platform/heap/asm/SaveRegisters_mips64.S (right):

https://codereview.chromium.org/476143002/diff/20001/Source/platform/heap/asm...
Source/platform/heap/asm/SaveRegisters_mips64.S:1: /*

Use the following 3-line copyright.

// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

[petarj, 2014-08-15 14:59:55]

https://codereview.chromium.org/476143002/diff/20001/Source/platform/heap/asm...
File Source/platform/heap/asm/SaveRegisters_mips64.S (right):

https://codereview.chromium.org/476143002/diff/20001/Source/platform/heap/asm...
Source/platform/heap/asm/SaveRegisters_mips64.S:1: /*
On 2014/08/15 14:43:21, haraken wrote:
> 
> Use the following 3-line copyright.
> 
> // Copyright 2014 The Chromium Authors. All rights reserved.
> // Use of this source code is governed by a BSD-style license that can be
> // found in the LICENSE file.

Done.

[Mads Ager (chromium), 2014-08-18 06:54:16]

https://codereview.chromium.org/476143002/diff/40001/Source/platform/heap/asm...
File Source/platform/heap/asm/SaveRegisters_mips64.S (right):

https://codereview.chromium.org/476143002/diff/40001/Source/platform/heap/asm...
Source/platform/heap/asm/SaveRegisters_mips64.S:16: // Reserve space for
callee-saved registers and return address.
Don't you need to reserve space for saving arguments passed in registers? If the
called function assumes that it has four words on the stack that it can use for
saving argument registers it might end up overwriting one of the value which we
have saved there and the GC would miss a pointer. The mips32 documentation that
I could find says that you have to allocate room for saving the four argument
register values. Is that not the case for mips64?  

Do you have a good link for the mips64 calling convention? Is it the same as the
32-bit one but with 64-bit value instead of 32-bit?

https://codereview.chromium.org/476143002/diff/40001/Source/wtf/CPU.h
File Source/wtf/CPU.h (right):

https://codereview.chromium.org/476143002/diff/40001/Source/wtf/CPU.h#newcode183
Source/wtf/CPU.h:183: /* CPU(MIPS64) - Mips 64-bit */
This change looks unrelated and unused. Could you remove it and reintroduce it
when needed?

[petarj, 2014-08-18 13:05:18]

New patch uploaded.

https://codereview.chromium.org/476143002/diff/40001/Source/platform/heap/asm...
File Source/platform/heap/asm/SaveRegisters_mips64.S (right):

https://codereview.chromium.org/476143002/diff/40001/Source/platform/heap/asm...
Source/platform/heap/asm/SaveRegisters_mips64.S:16: // Reserve space for
callee-saved registers and return address.
On 2014/08/18 06:54:16, Mads Ager (chromium) wrote:
> Don't you need to reserve space for saving arguments passed in registers? If
the
> called function assumes that it has four words on the stack that it can use
for
> saving argument registers it might end up overwriting one of the value which
we
> have saved there and the GC would miss a pointer. The mips32 documentation
that
> I could find says that you have to allocate room for saving the four argument
> register values. Is that not the case for mips64?  

No, it is not. No reserved space is needed or expected on n64 abi.
> 
> Do you have a good link for the mips64 calling convention? Is it the same as
the
> 32-bit one but with 64-bit value instead of 32-bit?

"See MIPS Run" should hold information to start with.
The book seems to be available for download on a few places.

https://codereview.chromium.org/476143002/diff/40001/Source/wtf/CPU.h
File Source/wtf/CPU.h (right):

https://codereview.chromium.org/476143002/diff/40001/Source/wtf/CPU.h#newcode183
Source/wtf/CPU.h:183: /* CPU(MIPS64) - Mips 64-bit */
On 2014/08/18 06:54:16, Mads Ager (chromium) wrote:
> This change looks unrelated and unused. Could you remove it and reintroduce it
> when needed?

Done.

[Mads Ager (chromium), 2014-08-18 13:11:12]

LGTM

Thanks for the pointer to "MIPS run". One of the first thing I found was exactly
this difference: "They do not require the caller to allocate stack space for
arguments
passed in registers."

[petarj, 2014-08-18 13:16:07]

The CQ bit was checked by petarj@mips.com

[commit-bot: I haz the power, 2014-08-18 13:17:00]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/petarj@mips.com/476143002/60001

[commit-bot: I haz the power, 2014-08-18 14:15:18]

Committed patchset #4 (60001) as 180461