lkml.org 
[lkml]   [1998]   [Mar]   [19]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
DateThu, 19 Mar 1998 10:25:48 +0100 (CET)
FromMarek Habersack <>
SubjectRe: is gcc 2.8 safe to use yet ?
On Wed, 18 Mar 1998, Bernhard Rosenkraenzer wrote:

> On Wed, 18 Mar 1998, Marek Habersack wrote:
> 
> > The XFree86 servers still don't run with a kernel compiled with a gcc 2.8.x
> > with the following command line:
> > 
> >   -march=pentium -O3 -fomit-frame-pointer <the usual align stuff>
> 
> They do work with a kernel compiled with (gcc-2.8 based) egcs and pgcc...
> Any reason not to use those?
No, not at all! I just check out all the possibilities. Since the current gcc
shares much code with egcc, I assumed they will produce equally good code. I
guess I was wrong. Yesterday I was doing some tests and it turned out that gcc
2.8.x generates wrong code when two things are true:

  1) the -fomit-frame-pointer flag is used
  2) the inlined C functions are used

The optimizer seems to lose sync when a function being inlined contains many
local variables - their addresses when traced under gdb appear to be ALWAYS
between 0x00 - 0x20 (at the least in the cases I have tested). The problem
disappears when the -fno-omit-frame-pointer flag is used.

later, marek
---
A bird in the hand makes it awfully hard to blow your nose.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu

\
 
 \ /
  Last update: 2005-03-22 12:41    [W:0.232 / U:0.370 seconds]
©2003-2008 Jasper Spaans