diff options
| -rw-r--r-- | fpu/softfloat-parts.c.inc | 21 | ||||
| -rw-r--r-- | fpu/softfloat.c | 103 |
2 files changed, 55 insertions, 69 deletions
diff --git a/fpu/softfloat-parts.c.inc b/fpu/softfloat-parts.c.inc index 3dacb5b4f0..bf935c4fc2 100644 --- a/fpu/softfloat-parts.c.inc +++ b/fpu/softfloat-parts.c.inc @@ -1075,3 +1075,24 @@ static FloatRelation partsN(compare)(FloatPartsN *a, FloatPartsN *b, b_sign: return b->sign ? float_relation_greater : float_relation_less; } + +/* + * Multiply A by 2 raised to the power N. + */ +static void partsN(scalbn)(FloatPartsN *a, int n, float_status *s) +{ + switch (a->cls) { + case float_class_snan: + case float_class_qnan: + parts_return_nan(a, s); + break; + case float_class_zero: + case float_class_inf: + break; + case float_class_normal: + a->exp += MIN(MAX(n, -0x10000), 0x10000); + break; + default: + g_assert_not_reached(); + } +} diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 6f1bbbe6cf..666b5a25d6 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -890,6 +890,12 @@ static int parts128_compare(FloatParts128 *a, FloatParts128 *b, #define parts_compare(A, B, S, Q) \ PARTS_GENERIC_64_128(compare, A)(A, B, S, Q) +static void parts64_scalbn(FloatParts64 *a, int n, float_status *s); +static void parts128_scalbn(FloatParts128 *a, int n, float_status *s); + +#define parts_scalbn(A, N, S) \ + PARTS_GENERIC_64_128(scalbn, A)(A, N, S) + /* * Helper functions for softfloat-parts.c.inc, per-size operations. */ @@ -3529,58 +3535,53 @@ FloatRelation float128_compare_quiet(float128 a, float128 b, float_status *s) return float128_do_compare(a, b, s, true); } -/* Multiply A by 2 raised to the power N. */ -static FloatParts64 scalbn_decomposed(FloatParts64 a, int n, float_status *s) -{ - if (unlikely(is_nan(a.cls))) { - parts_return_nan(&a, s); - } - if (a.cls == float_class_normal) { - /* The largest float type (even though not supported by FloatParts64) - * is float128, which has a 15 bit exponent. Bounding N to 16 bits - * still allows rounding to infinity, without allowing overflow - * within the int32_t that backs FloatParts64.exp. - */ - n = MIN(MAX(n, -0x10000), 0x10000); - a.exp += n; - } - return a; -} +/* + * Scale by 2**N + */ float16 float16_scalbn(float16 a, int n, float_status *status) { - FloatParts64 pa, pr; + FloatParts64 p; - float16_unpack_canonical(&pa, a, status); - pr = scalbn_decomposed(pa, n, status); - return float16_round_pack_canonical(&pr, status); + float16_unpack_canonical(&p, a, status); + parts_scalbn(&p, n, status); + return float16_round_pack_canonical(&p, status); } float32 float32_scalbn(float32 a, int n, float_status *status) { - FloatParts64 pa, pr; + FloatParts64 p; - float32_unpack_canonical(&pa, a, status); - pr = scalbn_decomposed(pa, n, status); - return float32_round_pack_canonical(&pr, status); + float32_unpack_canonical(&p, a, status); + parts_scalbn(&p, n, status); + return float32_round_pack_canonical(&p, status); } float64 float64_scalbn(float64 a, int n, float_status *status) { - FloatParts64 pa, pr; + FloatParts64 p; - float64_unpack_canonical(&pa, a, status); - pr = scalbn_decomposed(pa, n, status); - return float64_round_pack_canonical(&pr, status); + float64_unpack_canonical(&p, a, status); + parts_scalbn(&p, n, status); + return float64_round_pack_canonical(&p, status); } bfloat16 bfloat16_scalbn(bfloat16 a, int n, float_status *status) { - FloatParts64 pa, pr; + FloatParts64 p; - bfloat16_unpack_canonical(&pa, a, status); - pr = scalbn_decomposed(pa, n, status); - return bfloat16_round_pack_canonical(&pr, status); + bfloat16_unpack_canonical(&p, a, status); + parts_scalbn(&p, n, status); + return bfloat16_round_pack_canonical(&p, status); +} + +float128 float128_scalbn(float128 a, int n, float_status *status) +{ + FloatParts128 p; + + float128_unpack_canonical(&p, a, status); + parts_scalbn(&p, n, status); + return float128_round_pack_canonical(&p, status); } /* @@ -6638,42 +6639,6 @@ floatx80 floatx80_scalbn(floatx80 a, int n, float_status *status) aSign, aExp, aSig, 0, status); } -float128 float128_scalbn(float128 a, int n, float_status *status) -{ - bool aSign; - int32_t aExp; - uint64_t aSig0, aSig1; - - aSig1 = extractFloat128Frac1( a ); - aSig0 = extractFloat128Frac0( a ); - aExp = extractFloat128Exp( a ); - aSign = extractFloat128Sign( a ); - if ( aExp == 0x7FFF ) { - if ( aSig0 | aSig1 ) { - return propagateFloat128NaN(a, a, status); - } - return a; - } - if (aExp != 0) { - aSig0 |= UINT64_C(0x0001000000000000); - } else if (aSig0 == 0 && aSig1 == 0) { - return a; - } else { - aExp++; - } - - if (n > 0x10000) { - n = 0x10000; - } else if (n < -0x10000) { - n = -0x10000; - } - - aExp += n - 1; - return normalizeRoundAndPackFloat128( aSign, aExp, aSig0, aSig1 - , status); - -} - static void __attribute__((constructor)) softfloat_init(void) { union_float64 ua, ub, uc, ur; |