add clang-compatible thread-pointer code for mips

clang does not presently support the "v" constraint we want to use to
get the result from $3, and trying to use register...__asm__("$3") to
do the same invokes serious compiler bugs. so for now, i'm working
around the issue with an extra temp register and putting $3 in the
clobber list instead of using it as output. when the bugs in clang are
fixed, this issue should be revisited to generate smaller/faster code
like what gcc gets.

diff --git a/arch/mips/pthread_arch.h b/arch/mips/pthread_arch.h
index f75379cf834deb53c02c31c5f28584b75c0e7a44..77b7330dacfd1445d4635d64bb0c6ece1a87897c 100644 (file)
--- a/arch/mips/pthread_arch.h
+++ b/arch/mips/pthread_arch.h
@@ -1,7 +1,11 @@
 static inline struct pthread *__pthread_self()
 {
        struct pthread *self;
+#ifdef __clang__
+       __asm__ __volatile__ (".word 0x7c03e83b ; move %0, $3" : "=r" (self) : : "$3" );
+#else
        __asm__ __volatile__ (".word 0x7c03e83b" : "=v" (self) );
+#endif
        return self;
 }