[lkml]   [2009]   [Nov]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH][GIT PULL][v2.6.32] tracing/x86: Add check to detect GCC messing with mcount prologue
On Tue, Nov 24, 2009 at 03:32:20PM +0000, Andrew Haley wrote:
> Jakub Jelinek wrote:
> > On Tue, Nov 24, 2009 at 03:55:49PM +0100, Thomas Gleixner wrote:
> >>> you should compile your code with -maccumulate-outgoing-args, and there's
> >>> no need to use -mtune=generic. Is that right?
> >> Seems to work. What other side effects has that ?
> >
> > Faster code, significant increase in code size though.
> Does it affect code size when we don't have to realign the stack pointer?

Yes, a lot. The difference is that -maccumulate-outgoing-args allocates
space for arguments of the callee with most arguments in the prologue, using
subtraction from sp, then to pass arguments uses movl XXX, 4(%esp) etc.
and the stack pointer doesn't usually change within the function (except for
With -mno-accumulate-outgoing-args args are pushed using push instructions
and stack pointer is constantly changing.


 \ /
  Last update: 2009-11-24 16:39    [W:0.247 / U:0.124 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site