diff options
| -rw-r--r-- | fpu/softfloat.c | 75 | ||||
| -rw-r--r-- | include/fpu/softfloat.h | 2 |
2 files changed, 77 insertions, 0 deletions
diff --git a/fpu/softfloat.c b/fpu/softfloat.c index c63e011..d4ca7cf 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -3281,6 +3281,81 @@ float16 float32_to_float16(float32 a, flag ieee STATUS_PARAM) return roundAndPackFloat16(aSign, aExp, aSig, ieee STATUS_VAR); } +float64 float16_to_float64(float16 a, flag ieee STATUS_PARAM) +{ + flag aSign; + int_fast16_t aExp; + uint32_t aSig; + + aSign = extractFloat16Sign(a); + aExp = extractFloat16Exp(a); + aSig = extractFloat16Frac(a); + + if (aExp == 0x1f && ieee) { + if (aSig) { + return commonNaNToFloat64( + float16ToCommonNaN(a STATUS_VAR) STATUS_VAR); + } + return packFloat64(aSign, 0x7ff, 0); + } + if (aExp == 0) { + if (aSig == 0) { + return packFloat64(aSign, 0, 0); + } + + normalizeFloat16Subnormal(aSig, &aExp, &aSig); + aExp--; + } + return packFloat64(aSign, aExp + 0x3f0, ((uint64_t)aSig) << 42); +} + +float16 float64_to_float16(float64 a, flag ieee STATUS_PARAM) +{ + flag aSign; + int_fast16_t aExp; + uint64_t aSig; + uint32_t zSig; + + a = float64_squash_input_denormal(a STATUS_VAR); + + aSig = extractFloat64Frac(a); + aExp = extractFloat64Exp(a); + aSign = extractFloat64Sign(a); + if (aExp == 0x7FF) { + if (aSig) { + /* Input is a NaN */ + if (!ieee) { + float_raise(float_flag_invalid STATUS_VAR); + return packFloat16(aSign, 0, 0); + } + return commonNaNToFloat16( + float64ToCommonNaN(a STATUS_VAR) STATUS_VAR); + } + /* Infinity */ + if (!ieee) { + float_raise(float_flag_invalid STATUS_VAR); + return packFloat16(aSign, 0x1f, 0x3ff); + } + return packFloat16(aSign, 0x1f, 0); + } + shift64RightJamming(aSig, 29, &aSig); + zSig = aSig; + if (aExp == 0 && zSig == 0) { + return packFloat16(aSign, 0, 0); + } + /* Decimal point between bits 22 and 23. Note that we add the 1 bit + * even if the input is denormal; however this is harmless because + * the largest possible single-precision denormal is still smaller + * than the smallest representable half-precision denormal, and so we + * will end up ignoring aSig and returning via the "always return zero" + * codepath. + */ + zSig |= 0x00800000; + aExp -= 0x3F1; + + return roundAndPackFloat16(aSign, aExp, zSig, ieee STATUS_VAR); +} + /*---------------------------------------------------------------------------- | Returns the result of converting the double-precision floating-point value | `a' to the extended double-precision floating-point format. The conversion diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h index a634a4e..83d324a 100644 --- a/include/fpu/softfloat.h +++ b/include/fpu/softfloat.h @@ -298,6 +298,8 @@ INLINE float64 uint16_to_float64(uint16_t v STATUS_PARAM) *----------------------------------------------------------------------------*/ float16 float32_to_float16( float32, flag STATUS_PARAM ); float32 float16_to_float32( float16, flag STATUS_PARAM ); +float16 float64_to_float16(float64 a, flag ieee STATUS_PARAM); +float64 float16_to_float64(float16 a, flag ieee STATUS_PARAM); /*---------------------------------------------------------------------------- | Software half-precision operations. |