Remove -fno-omit-frame-pointer on ppc64
Anton Blanchard
anton at samba.org
Fri Apr 8 16:10:55 EST 2005
During some code inspection using gcc 4.0 I noticed a stack frame was
being created for a number of functions that didnt require it. For
example:
c0000000000df944 <._spin_unlock>:
c0000000000df944: fb e1 ff f0 std r31,-16(r1)
c0000000000df948: f8 21 ff c1 stdu r1,-64(r1)
c0000000000df94c: 7c 3f 0b 78 mr r31,r1
c0000000000df950: 7c 20 04 ac lwsync
c0000000000df954: e8 21 00 00 ld r1,0(r1)
c0000000000df958: 38 00 00 00 li r0,0
c0000000000df95c: 90 03 00 00 stw r0,0(r3)
c0000000000df960: eb e1 ff f0 ld r31,-16(r1)
c0000000000df964: 4e 80 00 20 blr
It turns out we are adding -fno-omit-frame-pointer to ppc64 which is
causing the above behaviour. Removing that flag results in much better
code:
c0000000000d5b30 <._spin_unlock>:
c0000000000d5b30: 7c 20 04 ac lwsync
c0000000000d5b34: 38 00 00 00 li r0,0
c0000000000d5b38: 90 03 00 00 stw r0,0(r3)
c0000000000d5b3c: 4e 80 00 20 blr
We dont require a frame pointer to debug on ppc64, so remove it.
Signed-off-by: Anton Blanchard <anton at samba.org>
diff -puN arch/ppc64/Kconfig~no_fomit_frame_pointer arch/ppc64/Kconfig
--- gr_work_small/arch/ppc64/Kconfig~no_fomit_frame_pointer 2005-04-08 00:59:19.208299928 -0500
+++ gr_work_small-anton/arch/ppc64/Kconfig 2005-04-08 00:59:19.218298342 -0500
@@ -40,10 +40,6 @@ config COMPAT
bool
default y
-config FRAME_POINTER
- bool
- default y
-
# We optimistically allocate largepages from the VM, so make the limit
# large enough (16MB). This badly named config option is actually
# max order + 1
_
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