298103 - i386 (80386) native atomic operation support is possible

Status: RESOLVED WONTFIX

(NSPR :: NSPR, enhancement)

Description

[kevdig]

User-Agent:       Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.8b2) Gecko/20050601
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8b2) Gecko/20050606

It is possible to add native atomic operation support for the 386 without
getting in the way of other processors.

Reproducible: Always

Comment 1

[kevdig]

Attachment: 386 version of NSPR atomic operations

This is a version of the NSPR atomic operations that will work on my trusty old
386 EISA machine.

If negative numbers or counts greater than 2^31-1 are needed this
implementation will break down.

Comment 2

[kevdig]

Attachment: remaining code patches for 386 support

These are the remaining code changes to enable a 386 compatible build. Mostly
build changes and a new js_CompareAndSwap() for jslock.c.

Adding '--target=i386-pc-linux-gnu' triggers a 386 build via the target_cpu
variable.

Comment 3

[kevdig]

Attachment: sample mozconfig for a 386 build

This is the mozconfig file I used to get a 386 build. Only notable difference
is the ac_add_options for --target.

Comment 4

[Wan-Teh Chang]

Thank you very much for the contribution.

All the products using NSPR require or recommend that
the CPU be Pentium or higher.  Pentium is 586, right?
If so, I don't want to check in the patches.

Comment 5

[Julien Pierre]

Solaris 8 still supports 486, and the NSS Solaris x86 binaries we deliver are
the same for s8/s9/s10 , so technically they would be expected to run on 486.
Not sure about 386 . 486 support was removed in Solaris 9. We'll be dropping
Solaris 8 support soon, so the statement that we require Pentium or higher will
become true at that point, but it isn't quite yet.

Comment 6

[Wan-Teh Chang]

I don't want to support x86 CPUs older than Pentium.
I'm willing to create a contrib directory in the NSPR
source tree or web site for such patches.