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Re: libstdc++ atomicity.h and ppc405 problem
Got it, at least mostly, thanks to trial-and-error and lots of grep.
Here is a patch for gcc3.0.2 which produces four libraries:
nof/libstdc++.a
nof/mcpu405/libstdc++.a
libstdc++.a
mcpu405/libstdc++.a
I'd like to suppress generation of mcpu405/libstdc++.a, since the ppc405
doesn't support hardware floating point, but I haven't figured out how.
Thinking about it makes my head hurt.
The patch conflates ppc403 and ppc405, so it's not worth using directly.
A patch for gcc3.1 would be similar except it could use -mcpu=405
in rs6000.h, and mcpu=405 in t-ppcos, and not get ppc403 and ppc405 mixed up.
Comments?
- Dan
(p.s. Fellow newbies: It's worth reading gcc/genmultilib as a supplement
to the scrawny manual section dealing with multilibs.
Also, which files in gcc/config are used is controlled by gcc/config.gcc.
The entry for powerpc-linux says
tmake_file="rs6000/t-ppcos t-slibgcc-elf-ver t-linux rs6000/t-ppccomm"
Each of those is responsible for different things; it looks like
MULTILIB_OPTIONS is in t-ppcos.)
--- gcc-3.0.2/gcc/config/rs6000/t-ppcos.orig Tue Apr 4 18:22:36 2000
+++ gcc-3.0.2/gcc/config/rs6000/t-ppcos Thu Jul 18 22:13:29 2002
@@ -1,7 +1,7 @@
# Multilibs for a powerpc hosted ELF target (linux, SVR4, solaris)
-MULTILIB_OPTIONS = msoft-float
-MULTILIB_DIRNAMES = nof
+MULTILIB_OPTIONS = msoft-float mcpu=403
+MULTILIB_DIRNAMES = nof mcpu405
MULTILIB_EXTRA_OPTS = fPIC mstrict-align
MULTILIB_EXCEPTIONS =
--- gcc-3.0.2/gcc/config/rs6000/rs6000.h.orig Thu Jul 18 15:27:37 2002
+++ gcc-3.0.2/gcc/config/rs6000/rs6000.h Thu Jul 18 15:34:39 2002
@@ -62,7 +62,7 @@
%{mcpu=rsc: -D_ARCH_PWR} \
%{mcpu=rsc1: -D_ARCH_PWR} \
%{mcpu=401: -D_ARCH_PPC} \
-%{mcpu=403: -D_ARCH_PPC} \
+%{mcpu=403: -D_ARCH_PPC -D__PPC405__} \
%{mcpu=505: -D_ARCH_PPC} \
%{mcpu=601: -D_ARCH_PPC -D_ARCH_PWR} \
%{mcpu=602: -D_ARCH_PPC} \
--- gcc-3.0.2/libstdc++-v3/config/cpu/powerpc/bits/atomicity.h.orig Tue Feb 27 16:04:08 2001
+++ gcc-3.0.2/libstdc++-v3/config/cpu/powerpc/bits/atomicity.h Thu Jul 18 13:36:39 2002
@@ -32,6 +32,18 @@
typedef int _Atomic_word;
+#ifdef __PPC405__
+/* fix PPC405 specific bug: errata #77 - JRO 07/18/02 & dank
+ See erratum 77 in
+ http://www-3.ibm.com/chips/techlib/techlib.nsf/techdocs/89DED00DEBFF54BF87256A8000491BA2/$file/405CR_C_errata_1_2.pdf
+ See also version 1.21 of arch/ppc/kernel/ppc_asm.h, Fri Sep 21 00:00:34 2001
+ in ChangeSet 1.489 at http://ppc.bkbits.net:8080/linuxppc_2_4_devel
+*/
+#define __LIBSTDCPP_PPC405_ERR77_SYNC "sync \n\t"
+#else
+#define __LIBSTDCPP_PPC405_ERR77_SYNC
+#endif
+
static inline _Atomic_word
__attribute__ ((__unused__))
__exchange_and_add (volatile _Atomic_word* __mem, int __val)
@@ -42,6 +54,7 @@
"0:\t"
"lwarx %0,0,%2 \n\t"
"add%I3 %1,%0,%3 \n\t"
+ __LIBSTDCPP_PPC405_ERR77_SYNC
"stwcx. %1,0,%2 \n\t"
"bne- 0b \n\t"
"/* End exchange & add */"
@@ -61,6 +74,7 @@
"0:\t"
"lwarx %0,0,%1 \n\t"
"add%I2 %0,%0,%2 \n\t"
+ __LIBSTDCPP_PPC405_ERR77_SYNC
"stwcx. %0,0,%1 \n\t"
"bne- 0b \n\t"
"/* End atomic add */"
@@ -81,6 +95,7 @@
"sub%I2c. %0,%0,%2 \n\t"
"cntlzw %0,%0 \n\t"
"bne- 1f \n\t"
+ __LIBSTDCPP_PPC405_ERR77_SYNC
"stwcx. %3,0,%1 \n\t"
"bne- 0b \n"
"1:\n\t"
@@ -100,6 +115,7 @@
"/* Inline always swap */\n"
"0:\t"
"lwarx %0,0,%1 \n\t"
+ __LIBSTDCPP_PPC405_ERR77_SYNC
"stwcx. %2,0,%1 \n\t"
"bne- 0b \n\t"
"/* End always swap */"
@@ -120,6 +136,7 @@
"lwarx %0,0,%1 \n\t"
"cmpwi %0,0 \n\t"
"bne- 1f \n\t"
+ __LIBSTDCPP_PPC405_ERR77_SYNC
"stwcx. %2,0,%1 \n\t"
"bne- 0b \n"
"1:\n\t"