LLVM is not supported on PPC64
http://llvm.org/bugs/show_bug.cgi?id=3729

with following patch I am able to build mesa for ppc and ppc64

diff --git a/mesa.spec b/mesa.spec
index 34fb028..78323ee 100644
--- a/mesa.spec
+++ b/mesa.spec
@@ -6,6 +6,14 @@
 %define with_hardware 1
 %endif

+%ifarch ppc64
+# LLVM is not supported on PPC64
+# http://llvm.org/bugs/show_bug.cgi?id=3729
+%define with_llvm 0
+%else
+%define with_llvm 1
+%endif
+
 %define _default_patch_fuzz 2

 %define manpages gl-manpages-1.0.1
@@ -64,7 +72,9 @@ BuildRequires: libXi-devel
 BuildRequires: libXmu-devel
 BuildRequires: elfutils
 BuildRequires: python
+%if %{with_llvm}
 BuildRequires: llvm-static
+%endif
 BuildRequires: libxml2-python
 BuildRequires: libudev-devel
 BuildRequires: libtalloc-devel
@@ -114,6 +124,7 @@ Group: User Interface/X Hardware Support
 %description dri-filesystem
 Mesa DRI driver filesystem

+%if %{with_llvm}
 %package dri-llvmcore
 Summary: Mesa common LLVM support
 Group: User Interface/X Hardware Support
@@ -122,6 +133,7 @@ Requires: mesa-dri-filesystem%{?_isa}
 Common DSO for LLVM support for gallium-based DRI drivers.  This package
 exists solely as a disk space hack for Mesa.  Do not link against this
 library if you are not Mesa.  You have been warned.
+%endif

 %package dri-drivers
 Summary: Mesa-based DRI drivers
@@ -251,10 +263,12 @@ make clean
 # just to be sure...
 [ `find . -name \*.o | wc -l` -eq 0 ] || exit 1

+%if %{with_llvm}
 # build llvmcore
 TOP=`pwd` make -f %{SOURCE4} llvmcore
 mkdir -p %{_lib}
 mv libllvmcore*.so %{_lib}
+%endif

 # now build the rest of mesa
 %configure %{common_flags} \
@@ -267,7 +281,9 @@ mv libllvmcore*.so %{_lib}
     --enable-egl \
     --enable-gles1 \
     --enable-gles2 \
+%if %{with_llvm}
     --enable-gallium-llvm \
+%endif
     --disable-gallium-intel \
     --disable-gallium-svga \
     --disable-gallium-egl \
@@ -298,7 +314,9 @@ make install DESTDIR=$RPM_BUILD_ROOT DRI_DIRS=

 # just the DRI drivers that are sane
 install -d $RPM_BUILD_ROOT%{_libdir}/dri
+%if %{with_llvm}
 install -m 0755 -t $RPM_BUILD_ROOT%{_libdir}/dri %{_lib}/libllvmcore-2.8.so >& /dev/null
+%endif
 # use gallium driver iff built
 [ -f %{_lib}/gallium/r300_dri.so ] && cp %{_lib}/gallium/r300_dri.so %{_lib}/r300_dri.so
 [ -f %{_lib}/gallium/r600_dri.so ] && cp %{_lib}/gallium/r600_dri.so %{_lib}/r600_dri.so
@@ -376,9 +394,11 @@ rm -rf $RPM_BUILD_ROOT
 %doc docs/COPYING
 %dir %{_libdir}/dri

+%if %{with_llvm}
 %files dri-llvmcore
 %defattr(-,root,root,-)
 %{_libdir}/dri/libllvmcore-2.8.so
+%endif

 %files dri-drivers
 %defattr(-,root,root,-)
@@ -387,8 +407,10 @@ rm -rf $RPM_BUILD_ROOT
 %{_libdir}/dri/r200_dri.so
 %{_libdir}/dri/r300_dri.so
 %{_libdir}/dri/r600_dri.so
+%ifnarch ppc ppc64
 %{_libdir}/dri/i915_dri.so
 %{_libdir}/dri/i965_dri.so
+%endif
 %{_libdir}/dri/nouveau_dri.so
 %{_libdir}/dri/nouveau_vieux_dri.so
 %endif
@@ -402,13 +424,13 @@ rm -rf $RPM_BUILD_ROOT
 %ifarch %{ix86}
 %{_libdir}/dri/i810_dri.so
 %{_libdir}/dri/sis_dri.so
-%endif
 %{_libdir}/dri/mga_dri.so
-%{_libdir}/dri/r128_dri.so
 %{_libdir}/dri/savage_dri.so
-%{_libdir}/dri/tdfx_dri.so
 %{_libdir}/dri/unichrome_dri.so
 %endif
+%{_libdir}/dri/r128_dri.so
+%{_libdir}/dri/tdfx_dri.so
+%endif

 %files libGL-devel
 %defattr(-,root,root,-)
@@ -473,6 +495,10 @@ rm -rf $RPM_BUILD_ROOT
 %{_libdir}/libOSMesa.so

 %changelog
+* Mon Feb 07 2011 Adrian Reber <adrian> 7.10-0.25
+- build without llvm on ppc64
+- exclude i915_dri, i965_dri, mga_dri, savage_dri, unichrome_dri on ppc/ppc64
+
 * Thu Jan 20 2011 Ben Skeggs <bskeggs> 7.10-0.24
 - nouveau: move out of -experimental