On Wed, Feb 04, 2009 at 07:35:54PM -0500, Steven Rostedt wrote: > > On Thu, 2009-02-05 at 11:31 +1100, Benjamin Herrenschmidt wrote: > > On Wed, 2009-02-04 at 18:08 +0300, Anton Vorontsov wrote: > > > Remove -fno-omit-frame-pointer flag from CFLAGS. > > > Remove -fno-omit-frame-pointer workarounds. > > > > But what about -pg -requires -fno-omit-frame-pointer ? > > I don't think it requires -fno-omit-frame-pointer. It is just > incompatible with -fomit-frame-pointer. Yep, -fno-omit-frame-poiner isn't needed for -pg. I explained this in http://lkml.org/lkml/2009/2/3/342 : | Ah... | | $ gcc -pg -fomit-frame-pointer -S c.c | gcc: -pg and -fomit-frame-pointer are incompatible | | It's hard-coded in gcc, in the code that don't know about | architecture details. | | But on PowerPC -O1 implies -fomit-frame-pointer, that is | | gcc -pg -O1 -fno-omit-frame-pointer | and | gcc -pg -O1 | | produce different outputs. Thus -pg -O should be the same | as "-pg -O -fomit-framepointer". That is, `gcc -O -pg -fno-omit-frame-pointer -S` output: main: mflr 0 stw 0,4(1) bl _mcount stwu 1,-16(1) mflr 0 stw 0,20(1) stw 31,12(1) mr 31,1 li 3,0 lwz 11,0(1) lwz 0,4(11) mtlr 0 lwz 31,-4(11) mr 1,11 blr ^^ -pg works (_mcount call), but r31 wasted. Now `gcc -O -pg -S` output: main: mflr 0 stw 0,4(1) bl _mcount stwu 1,-16(1) mflr 0 stw 0,20(1) li 3,0 lwz 0,20(1) mtlr 0 addi 1,1,16 blr ^^ _mcount is still there, and r31 isn't used. -- Anton Vorontsov email: cbouatmailru@xxxxxxxxx irc://irc.freenode.net/bd2 -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
