softfloat: Extend float_exception_flags to 16 bits

We will shortly have more than 8 bits of exceptions.
Repack the existing flags into low bits and reformat to hex.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211119160502.17432-2-richard.henderson@linaro.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

include/fpu/softfloat-types.h

@@ -145,13 +145,13 @@ typedef enum __attribute__((__packed__)) {
  */
 
 enum {
-    float_flag_invalid   =  1,
-    float_flag_divbyzero =  4,
-    float_flag_overflow  =  8,
-    float_flag_underflow = 16,
-    float_flag_inexact   = 32,
-    float_flag_input_denormal = 64,
-    float_flag_output_denormal = 128
+    float_flag_invalid         = 0x0001,
+    float_flag_divbyzero       = 0x0002,
+    float_flag_overflow        = 0x0004,
+    float_flag_underflow       = 0x0008,
+    float_flag_inexact         = 0x0010,
+    float_flag_input_denormal  = 0x0020,
+    float_flag_output_denormal = 0x0040,
 };
 
 /*
@@ -171,8 +171,8 @@ typedef enum __attribute__((__packed__)) {
  */
 
 typedef struct float_status {
+    uint16_t float_exception_flags;
     FloatRoundMode float_rounding_mode;
-    uint8_t     float_exception_flags;
     FloatX80RoundPrec floatx80_rounding_precision;
     bool tininess_before_rounding;
     /* should denormalised results go to zero and set the inexact flag? */

include/fpu/softfloat.h

@@ -100,7 +100,7 @@ typedef enum {
 | Routine to raise any or all of the software IEC/IEEE floating-point
 | exception flags.
 *----------------------------------------------------------------------------*/
-static inline void float_raise(uint8_t flags, float_status *status)
+static inline void float_raise(uint16_t flags, float_status *status)
 {
     status->float_exception_flags |= flags;
 }