defined but not used errors on Solaris/SPARC

I recently tried building GHC on Solaris and I got a ton of these files when compiling the bootstrapping copy of Cabal:

"/afs/sipb/user/ezyang/ghc-7.8.2/usr/bin//ghc" -H32m -O -Werror -Wall -H64m -O0 \
               -optc-Werror -optc-Wall -optc-fno-stack-protector \
                \
               --make utils/ghc-cabal/Main.hs -o utils/ghc-cabal/dist/build/tmp/ghc-cabal \
               -no-user-package-db \
               -Wall -fno-warn-unused-imports -fno-warn-warnings-deprecations \
               -DCABAL_VERSION=1,21,1,0 \
               -DBOOTSTRAPPING \
               -odir  bootstrapping \
               -hidir bootstrapping \
               -ilibraries/Cabal/Cabal \
               -ilibraries/binary/src -DGENERICS \
               -ilibraries/filepath \
               -ilibraries/hpc \
               -w
"rm" -f compiler/stage1/build/Config.hs  
Creating compiler/stage1/build/Config.hs ... 
"rm" -f utils/ghc-pkg/dist/build/Version.hs  
echo "module Version where"                    >> utils/ghc-pkg/dist/build/Version.hs
echo "version, targetOS, targetARCH :: String" >> utils/ghc-pkg/dist/build/Version.hs
echo "version    = \"7.9.20141204\""      >> utils/ghc-pkg/dist/build/Version.hs
echo "targetOS   = \"solaris2\""        >> utils/ghc-pkg/dist/build/Version.hs
echo "targetARCH = \"sparc\""      >> utils/ghc-pkg/dist/build/Version.hs
done.
[ 1 of 86] Compiling Distribution.Compat.CreatePipe ( libraries/Cabal/Cabal/Distribution/Compat/CreatePipe.hs, bootstrapping/Distribution/Compat/CreatePipe.o )
cc1: warnings being treated as errors
/tmp/ghc322370_0/ghc322370_21.hc: In function ‘s1xM_entry’:

/tmp/ghc322370_0/ghc322370_21.hc:21:0:
     error: label ‘_c312’ defined but not used
/tmp/ghc322370_0/ghc322370_21.hc: In function ‘s1xK_entry’:

/tmp/ghc322370_0/ghc322370_21.hc:63:0:
     error: label ‘_c31b’ defined but not used

Maybe the 7.8.2 codegen which I bootstrapped from is buggy in some way? It makes it mildly difficult to actually validate.

Trac metadata

Trac field	Value
Version	7.8.2
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler (NCG)
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	simonmar
Operating system
Architecture