code review 15750044: cmd/6l, cmd/8l, cmd/ld: support for Native Client

cmd/6l, cmd/8l, cmd/ld: support for Native Client

See golang.org/s/go13nacl for design overview.

This CL is publicly visible but not CC'ed to golang-dev,
to avoid distracting from the preparation of the Go 1.2
release.

This CL and the others will be checked into my rsc-go13nacl
clone repo for now, and I will send CLs against the main
repo early in the Go 1.3 development.

[khr, 2013-11-07 22:43:30]

LGTM.

https://codereview.appspot.com/15750044/diff/150001/src/cmd/6l/obj.c
File src/cmd/6l/obj.c (right):

https://codereview.appspot.com/15750044/diff/150001/src/cmd/6l/obj.c#newcode143
src/cmd/6l/obj.c:143: IntSize = 4;
Shouldn't IntSize be 8?

[rsc, 2013-11-08 00:38:13]

https://codereview.appspot.com/15750044/diff/150001/src/cmd/6l/obj.c
File src/cmd/6l/obj.c (right):

https://codereview.appspot.com/15750044/diff/150001/src/cmd/6l/obj.c#newcode143
src/cmd/6l/obj.c:143: IntSize = 4;
On 2013/11/07 22:43:30, khr wrote:
> Shouldn't IntSize be 8?

It is the size of a Go int, which is only 4 for amd64p32.
We started with 4 on amd64 and upped it to 8 mainly to match the pointer size,
so that a slice of bytes could address as much as a pointer can. For amd64p32 I
chose to keep int and pointer matching in size, like on the other systems.
Especially when used as a count of things in memory, an 8-byte int would be a
waste since a 4-byte int would work just fine.

Basically amd64p32 should be thought of as the 386 data model with more
registers and better support for 64-bit math.

[rsc, 2013-11-11 14:50:14]

Hello khr@golang.org,

I'd like you to review this change to
https://code.google.com/r/rsc-go13nacl

[rsc, 2013-11-11 14:50:21]

*** Submitted as 228a67edf974 ***

cmd/6l, cmd/8l, cmd/ld: support for Native Client

See golang.org/s/go13nacl for design overview.

This CL is publicly visible but not CC'ed to golang-dev,
to avoid distracting from the preparation of the Go 1.2
release.

This CL and the others will be checked into my rsc-go13nacl
clone repo for now, and I will send CLs against the main
repo early in the Go 1.3 development.

R=khr
https://codereview.appspot.com/15750044