Changing default -march flag

[Michael Gerdts <gerdts at cae dot wisc dot edu>]

When I built gcc 2.95.2, I used the flag --with-cpu=ultrasparc.  I have run
across optimization bugs that do not appear with the -msupersparc option.
(A bug report has been sent to gcc-bugs.)  To work around this bug I would
like to change the default architecture from ultrasparc to supersparc.

I suspect that I can change the default build architecture by editing
$prefix/lib/gcc-lib/sparc-sun-solaris2.7/2.95.2/specs.  Are there any hints
as to what I should change?  I would prefer not to have to wait for a
complete build to take place.

Attached is my specs file.

TIA,
Mike

-- 
Mike Gerdts
UNIX Systems Administrator
Computer-Aided Engineering Center
University of Wisconsin - Madison
*asm:
%{v:-V} %{Qy:} %{!Qn:-Qy} %{n} %{T} %{Ym,*} %{Wa,*:%*} -s %{fpic:-K PIC} %{fPIC:-K PIC} %(asm_cpu) 

*asm_final:
%|

*cpp:
%(cpp_cpu) %(cpp_arch) %(cpp_endian) %(cpp_subtarget)

*cc1:
%{sun4:} %{target:} %{mcypress:-mcpu=cypress} %{msparclite:-mcpu=sparclite} %{mf930:-mcpu=f930} %{mf934:-mcpu=f934} %{mv8:-mcpu=v8} %{msupersparc:-mcpu=supersparc} 

*cc1plus:


*endfile:
crtend.o%s crtn.o%s

*link:
%{h*} %{v:-V}    %{b} %{Wl,*:%*}    %{static:-dn -Bstatic}    %{shared:-G -dy %{!mimpure-text:-z text}}    %{symbolic:-Bsymbolic -G -dy -z text}    %{G:-G}    %{YP,*}    %{R*}    %{compat-bsd:      %{!YP,*:%{p:-Y P,/usr/ucblib:/usr/ccs/lib/libp:/usr/lib/libp:/usr/ccs/lib:/usr/lib}        %{pg:-Y P,/usr/ucblib:/usr/ccs/lib/libp:/usr/lib/libp:/usr/ccs/lib:/usr/lib}        %{!p:%{!pg:-Y P,/usr/ucblib:/usr/ccs/lib:/usr/lib}}}      -R /usr/ucblib}    %{!compat-bsd:      %{!YP,*:%{p:-Y P,/usr/ccs/lib/libp:/usr/lib/libp:/usr/ccs/lib:/usr/lib}        %{pg:-Y P,/usr/ccs/lib/libp:/usr/lib/libp:/usr/ccs/lib:/usr/lib}        %{!p:%{!pg:-Y P,/usr/ccs/lib:/usr/lib}}}}    %{Qy:} %{!Qn:-Qy}

*lib:
%{compat-bsd:-lucb -lsocket -lnsl -lelf -laio}    %{!shared:     %{!symbolic:       %{pthreads:-lpthread}        %{!pthreads:%{threads:-lthread}}        -lc}}

*libgcc:
-lgcc

*startfile:
%{!shared: 			 %{!symbolic: 			  %{p:mcrt1.o%s}                           %{!p: 	                    %{pg:gcrt1.o%s gmon.o%s}                             %{!pg:crt1.o%s}}}} 			crti.o%s 			%{ansi:values-Xc.o%s} 			%{!ansi: 			 %{traditional:values-Xt.o%s} 			 %{!traditional:values-Xa.o%s}} 			crtbegin.o%s

*switches_need_spaces:


*signed_char:
%{funsigned-char:-D__CHAR_UNSIGNED__}

*predefines:
-Dsparc -Dsun -Dunix -D__svr4__ -D__SVR4 -Asystem(unix) -Asystem(svr4)

*cross_compile:
0

*version:
2.95.2

*multilib:
. ;

*multilib_defaults:


*multilib_extra:


*multilib_matches:


*linker:
collect2

*cpp_cpu:
%{mcypress:} %{msparclite:-D__sparclite__} %{mf930:-D__sparclite__} %{mf934:-D__sparclite__} %{mv8:-D__sparc_v8__} %{msupersparc:-D__supersparc__ -D__sparc_v8__} %{mcpu=sparclet:-D__sparclet__} %{mcpu=tsc701:-D__sparclet__} %{mcpu=sparclite:-D__sparclite__} %{mcpu=f930:-D__sparclite__} %{mcpu=f934:-D__sparclite__} %{mcpu=v8:-D__sparc_v8__} %{mcpu=supersparc:-D__supersparc__ -D__sparc_v8__} %{mcpu=hypersparc:-D__hypersparc__ -D__sparc_v8__} %{mcpu=sparclite86x:-D__sparclite86x__ -D__sparc_v8__} %{mcpu=v9:-D__sparc_v9__} %{mcpu=ultrasparc:-D__sparc_v9__} %{!mcpu*:%{!mcypress:%{!msparclite:%{!mf930:%{!mf934:%{!mv8:%{!msupersparc:%(cpp_cpu_default)}}}}}}} 

*cpp_cpu_default:


*cpp_arch32:
-D__GCC_NEW_VARARGS__ -Acpu(sparc) -Amachine(sparc)

*cpp_arch64:
-D__arch64__ -Acpu(sparc64) -Amachine(sparc64)

*cpp_arch_default:
-D__GCC_NEW_VARARGS__ -Acpu(sparc) -Amachine(sparc)

*cpp_arch:
%{m32:%(cpp_arch32)} %{m64:%(cpp_arch64)} %{!m32:%{!m64:%(cpp_arch_default)}} 

*cpp_endian:
%{mlittle-endian:-D__LITTLE_ENDIAN__} %{mlittle-endian-data:-D__LITTLE_ENDIAN_DATA__}

*cpp_subtarget:
%{pthreads:-D_REENTRANT -D_PTHREADS} %{!pthreads:%{threads:-D_REENTRANT -D_SOLARIS_THREADS}} %{compat-bsd:-iwithprefixbefore ucbinclude -I/usr/ucbinclude} 

*asm_cpu:
%{mcpu=v8plus:-xarch=v8plus} %{mcpu=ultrasparc:-xarch=v8plusa} %{!mcpu*:%(asm_cpu_default)} 

*asm_cpu_default:
-xarch=v8plusa

*asm_arch32:
-32

*asm_arch64:
-64

*asm_arch_default:
-32

*asm_arch:
%{m32:%(asm_arch32)} %{m64:%(asm_arch64)} %{!m32:%{!m64:%(asm_arch_default)}} 

*link_command:
%{!fsyntax-only:  %{!c:%{!M:%{!MM:%{!E:%{!S:%(linker) %l %X %{o*} %{A} %{d} %{e*} %{m} %{N} %{n} 			%{r} %{s} %{t} %{u*} %{x} %{z} %{Z}			%{!A:%{!nostdlib:%{!nostartfiles:%S}}}			%{static:} %{L*} %D %o			%{!nostdlib:%{!nodefaultlibs:%G %L %G}}			%{!A:%{!nostdlib:%{!nostartfiles:%E}}}			%{T*}			
 }}}}}}