mips: add mips-sf subarch support (soft-float)
Userspace emulated floating-point (gcc -msoft-float) is not compatible
with the default mips abi (assumes an FPU or in kernel emulation of it).
Soft vs hard float abi should not be mixed, __mips_soft_float is checked
in musl's configure script and there is no runtime check. The -sf subarch
does not save/restore floating-point registers in setjmp/longjmp and only
provides dummy fenv implementation.
diff --git a/configure b/configure
index e4a5418..c622366 100755
--- a/configure
+++ b/configure
@@ -413,8 +413,10 @@
trycppif __ARM_PCS_VFP "$t" && SUBARCH=${SUBARCH}hf
fi
-test "$ARCH" = "mips" && trycppif "_MIPSEL || __MIPSEL || __MIPSEL__" "$t" \
-&& SUBARCH=${SUBARCH}el
+if test "$ARCH" = "mips" ; then
+trycppif "_MIPSEL || __MIPSEL || __MIPSEL__" "$t" && SUBARCH=${SUBARCH}el
+trycppif __mips_soft_float "$t" && SUBARCH=${SUBARCH}-sf
+fi
test "$ARCH" = "microblaze" && trycppif __MICROBLAZEEL__ "$t" \
&& SUBARCH=${SUBARCH}el