From: Philip Flip Kromer <flip@mr...> - 2003-04-21 11:25:23
--- Matthew Lane <mlane@...> wrote:
> Your most recent mod to Makefile-aix causes a linker error on Longhorn.
> I am using v1.8 without any problem, 1.9 creates the problem.
The IBM Compiler, i discovered, doesn't like it if you use -qipa and
-qextchk at the same time. I can't tell why that is, so for now I made the
default, CFLAGS_OPT_CRAZY, have -qnoipa; and I added CFLAGS_OPT_NUTSO, with
-qipa turned on. If you use that choice, de-select -qextchk in CFLAGS_LINT.
It seems that -qipa drastically increases compile time, with uncertain
runtime benefits. (ipa means "interprocedural analysis;" see
Tell me if you notice any improvement between -qipa and -qnoipa.
I also took another tour through the xlc manpage and changed settings for
-qfloat= fold evaluate constant float expressions at compile time
fltint speed up conversions by not checking overflow
hssngl suppress rounding to improve performance
hsflt suppress all rounding and convert from float
to int with inline code; more dangerous than hssngl
-qflttrap -- adds extra code to trap floating-point exceptions
-qinitauto=XX -- adds extra code to initialize storage to hex value "XX".
-qheapdebug -- use debug_malloc, etc; also preinitialize locals
If you want to be brave uncomment parts of CFLAGS_CHECK to enable various