Extract expF8UI and fracF8UI based on fp8Mode

Author: Omar Almatov

softfloat/internals.h

@@ -83,13 +83,17 @@ int_fast64_t
 int_fast64_t softfloat_roundMToI64( bool, uint32_t *, uint_fast8_t, bool );
 #endif
 
+/*----------------------------------------------------------------------------
+*---------------------------------------------------------------------------*/
+#define f8ExpWidth softfloat_fp8ExpWidths[softfloat_fp8Mode]
+
 /*----------------------------------------------------------------------------
 *----------------------------------------------------------------------------*/
 #define isNaNF8UI( a ) ((bool) (((uint8_t) a) == defaultNaNF8UI))
 #define isInfF8UI( a ) ((bool) ((((uint8_t) a) & 0x7F)  == 0x7F))
 #define signF8UI( a ) ((bool) ((uint16_t) (a)>>7))
-#define expF8UI( a ) ((int_fast8_t) ((a)>>4) & 0x7)
-#define fracF8UI( a ) ((a) & 0xF)
+#define expF8UI( a ) ((int_fast8_t) ((a)>>(7-f8ExpWidth)) & ((0x1<<f8ExpWidth)-1))
+#define fracF8UI( a ) ((a) & ((0x1<<(f8ExpWidth+1))-1))
 #define defaultInfF8UI 0x7F
 #define signInfF8UI( sign ) (((uint8_t) (sign)<<7) | defaultInfF8UI)
 #define packToF8UI( sign, exp, sig ) (((uint8_t) (sign)<<7) + ((uint8_t) (exp)<<4) + (sig))

softfloat/softfloat.h

@@ -79,6 +79,8 @@ enum {
     softfloat_fp8_8p3 = 2
 };
 
+extern THREAD_LOCAL uint_fast8_t softfloat_fp8ExpWidths[3];
+
 /*----------------------------------------------------------------------------
 | Software floating-point rounding mode.  (Mode "odd" is supported only if
 | SoftFloat is compiled with macro 'SOFTFLOAT_ROUND_ODD' defined.)

softfloat/softfloat_state.c

@@ -45,6 +45,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #endif
 
 THREAD_LOCAL uint_fast8_t softfloat_fp8Mode = softfloat_fp8_8p5;
+THREAD_LOCAL uint_fast8_t softfloat_fp8ExpWidths[3] = {3, 4, 5};
 THREAD_LOCAL uint_fast8_t softfloat_roundingMode = softfloat_round_near_even;
 THREAD_LOCAL uint_fast8_t softfloat_detectTininess = init_detectTininess;
 THREAD_LOCAL uint_fast8_t softfloat_exceptionFlags = 0;