add m68k port

three ABIs are supported: the default with 68881 80-bit fpu format and
results returned in floating point registers, softfloat-only with the
same format, and coldfire fpu with IEEE single/double only. only the
first is tested at all, and only under qemu which has fpu emulation
bugs.

basic functionality smoke tests have been performed for the most
common arch-specific breakage via libc-test and qemu user-level
emulation. some sysvipc failures remain, but are shared with other big
endian archs and will be fixed separately.

1 files changed, 29 insertions, 0 deletions

diff --git a/arch/m68k/bits/fenv.h b/arch/m68k/bits/fenv.h
new file mode 100644
index 00000000..c90a4a58
--- /dev/null
+++ b/arch/m68k/bits/fenv.h
@@ -0,0 +1,29 @@
+#if __HAVE_68881__ || __mcffpu__
+
+#define FE_INEXACT    8
+#define FE_DIVBYZERO  16
+#define FE_UNDERFLOW  32
+#define FE_OVERFLOW   64
+#define FE_INVALID    128
+
+#define FE_ALL_EXCEPT 0xf8
+
+#define FE_TONEAREST  0
+#define FE_TOWARDZERO 16
+#define FE_DOWNWARD   32
+#define FE_UPWARD     48
+
+#else
+
+#define FE_ALL_EXCEPT 0
+#define FE_TONEAREST  0
+
+#endif
+
+typedef unsigned fexcept_t;
+
+typedef struct {
+	unsigned __control_register, __status_register, __instruction_address;
+} fenv_t;
+
+#define FE_DFL_ENV      ((const fenv_t *) -1)