Bug 627482

Summary:	sys-devel/gcc - libgcc calls __get_cpuid with 0 level breaks on early 486
Product:	Gentoo Linux	Reporter:	tedheadster
Component:	Current packages	Assignee:	Gentoo Toolchain Maintainers <toolchain>
Status:	RESOLVED OBSOLETE
Severity:	normal	CC:	floppym
Priority:	Normal
Version:	unspecified
Hardware:	All
OS:	Linux
URL:	https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68491
Whiteboard:	masked in 17.0 profiles
Package list:		Runtime testing required:	---
Bug Depends on:	638030
Bug Blocks:

Description tedheadster 2017-08-10 19:34:29 UTC

The gcc compiler incorrectly detects support for the CPUID instruction on first generation i80486 processors (which lack it). This causes most programs linked to libgcc_s.so.1 to error out. Unfortunately, that is a huge number of programs.

This has been fixed in upstream gcc versions 5.x, 6.x, and 7.x. Please backport the patch or upgrade.

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68491

Comment 1 Mike Gilbert gentoo-dev

2017-08-10 19:38:00 UTC

I am rather doubtful that anyone would be running Gentoo on a i486 these days, so this hardly seems worth a backport.

Comment 2 tedheadster 2017-08-10 19:50:26 UTC

I am running on an i486 for regression testing. Testing on old hardware has  turned up some bugs that were worth fixing (see "nohz problem with idle time on old hardware" on linux kernel mailing list for an example).

While not particularly interesting, the upstream gcc team thought it was worth fixing and backporting.

Comment 3 Mike Gilbert gentoo-dev

2017-08-10 21:12:01 UTC

GCC 6.4.0 already has the fix. I would guess a 7.2.0 release is due soon. 5.5.0 is probably farther off, if it even happens.

Comment 4 Andreas K. Hüttel archtester

2017-10-03 20:13:38 UTC

(In reply to Mike Gilbert from comment #3)
> GCC 6.4.0 already has the fix. I would guess a 7.2.0 release is due soon.
> 5.5.0 is probably farther off, if it even happens.

6.4 and 7.2 are in Gentoo, and 6.4.0 will get stabilized soon.

Comment 5 Sergei Trofimovich (RETIRED) gentoo-dev

2019-02-14 07:27:14 UTC

6.4.0 is stable everywhere.