| 0,0 → 1,294 |
|---|
| /* |
| * Copyright (C) 2005 Josef Cejka |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /** @addtogroup softfloat |
| * @{ |
| */ |
| /** @file |
| */ |
| |
| #include<sftypes.h> |
| #include<mul.h> |
| #include<comparison.h> |
| #include<common.h> |
| |
| /** Multiply two 32 bit float numbers |
| * |
| */ |
| float32 mulFloat32(float32 a, float32 b) |
| { |
| float32 result; |
| uint64_t frac1, frac2; |
| int32_t exp; |
| |
| result.parts.sign = a.parts.sign ^ b.parts.sign; |
| |
| if (isFloat32NaN(a) || isFloat32NaN(b) ) { |
| /* TODO: fix SigNaNs */ |
| if (isFloat32SigNaN(a)) { |
| result.parts.fraction = a.parts.fraction; |
| result.parts.exp = a.parts.exp; |
| return result; |
| }; |
| if (isFloat32SigNaN(b)) { /* TODO: fix SigNaN */ |
| result.parts.fraction = b.parts.fraction; |
| result.parts.exp = b.parts.exp; |
| return result; |
| }; |
| /* set NaN as result */ |
| result.binary = FLOAT32_NAN; |
| return result; |
| }; |
| |
| if (isFloat32Infinity(a)) { |
| if (isFloat32Zero(b)) { |
| /* FIXME: zero * infinity */ |
| result.binary = FLOAT32_NAN; |
| return result; |
| } |
| result.parts.fraction = a.parts.fraction; |
| result.parts.exp = a.parts.exp; |
| return result; |
| } |
| |
| if (isFloat32Infinity(b)) { |
| if (isFloat32Zero(a)) { |
| /* FIXME: zero * infinity */ |
| result.binary = FLOAT32_NAN; |
| return result; |
| } |
| result.parts.fraction = b.parts.fraction; |
| result.parts.exp = b.parts.exp; |
| return result; |
| } |
| |
| /* exp is signed so we can easy detect underflow */ |
| exp = a.parts.exp + b.parts.exp; |
| exp -= FLOAT32_BIAS; |
| |
| if (exp >= FLOAT32_MAX_EXPONENT) { |
| /* FIXME: overflow */ |
| /* set infinity as result */ |
| result.binary = FLOAT32_INF; |
| result.parts.sign = a.parts.sign ^ b.parts.sign; |
| return result; |
| }; |
| |
| if (exp < 0) { |
| /* FIXME: underflow */ |
| /* return signed zero */ |
| result.parts.fraction = 0x0; |
| result.parts.exp = 0x0; |
| return result; |
| }; |
| |
| frac1 = a.parts.fraction; |
| if (a.parts.exp > 0) { |
| frac1 |= FLOAT32_HIDDEN_BIT_MASK; |
| } else { |
| ++exp; |
| }; |
| |
| frac2 = b.parts.fraction; |
| |
| if (b.parts.exp > 0) { |
| frac2 |= FLOAT32_HIDDEN_BIT_MASK; |
| } else { |
| ++exp; |
| }; |
| |
| frac1 <<= 1; /* one bit space for rounding */ |
| |
| frac1 = frac1 * frac2; |
| /* round and return */ |
| |
| while ((exp < FLOAT32_MAX_EXPONENT) && (frac1 >= ( 1 << (FLOAT32_FRACTION_SIZE + 2)))) { |
| /* 23 bits of fraction + one more for hidden bit (all shifted 1 bit left)*/ |
| ++exp; |
| frac1 >>= 1; |
| }; |
| |
| /* rounding */ |
| /* ++frac1; FIXME: not works - without it is ok */ |
| frac1 >>= 1; /* shift off rounding space */ |
| |
| if ((exp < FLOAT32_MAX_EXPONENT) && (frac1 >= (1 << (FLOAT32_FRACTION_SIZE + 1)))) { |
| ++exp; |
| frac1 >>= 1; |
| }; |
| |
| if (exp >= FLOAT32_MAX_EXPONENT ) { |
| /* TODO: fix overflow */ |
| /* return infinity*/ |
| result.parts.exp = FLOAT32_MAX_EXPONENT; |
| result.parts.fraction = 0x0; |
| return result; |
| } |
| |
| exp -= FLOAT32_FRACTION_SIZE; |
| |
| if (exp <= FLOAT32_FRACTION_SIZE) { |
| /* denormalized number */ |
| frac1 >>= 1; /* denormalize */ |
| while ((frac1 > 0) && (exp < 0)) { |
| frac1 >>= 1; |
| ++exp; |
| }; |
| if (frac1 == 0) { |
| /* FIXME : underflow */ |
| result.parts.exp = 0; |
| result.parts.fraction = 0; |
| return result; |
| }; |
| }; |
| result.parts.exp = exp; |
| result.parts.fraction = frac1 & ( (1 << FLOAT32_FRACTION_SIZE) - 1); |
| |
| return result; |
| |
| } |
| |
| /** Multiply two 64 bit float numbers |
| * |
| */ |
| float64 mulFloat64(float64 a, float64 b) |
| { |
| float64 result; |
| uint64_t frac1, frac2; |
| int32_t exp; |
| |
| result.parts.sign = a.parts.sign ^ b.parts.sign; |
| |
| if (isFloat64NaN(a) || isFloat64NaN(b) ) { |
| /* TODO: fix SigNaNs */ |
| if (isFloat64SigNaN(a)) { |
| result.parts.fraction = a.parts.fraction; |
| result.parts.exp = a.parts.exp; |
| return result; |
| }; |
| if (isFloat64SigNaN(b)) { /* TODO: fix SigNaN */ |
| result.parts.fraction = b.parts.fraction; |
| result.parts.exp = b.parts.exp; |
| return result; |
| }; |
| /* set NaN as result */ |
| result.binary = FLOAT64_NAN; |
| return result; |
| }; |
| |
| if (isFloat64Infinity(a)) { |
| if (isFloat64Zero(b)) { |
| /* FIXME: zero * infinity */ |
| result.binary = FLOAT64_NAN; |
| return result; |
| } |
| result.parts.fraction = a.parts.fraction; |
| result.parts.exp = a.parts.exp; |
| return result; |
| } |
| |
| if (isFloat64Infinity(b)) { |
| if (isFloat64Zero(a)) { |
| /* FIXME: zero * infinity */ |
| result.binary = FLOAT64_NAN; |
| return result; |
| } |
| result.parts.fraction = b.parts.fraction; |
| result.parts.exp = b.parts.exp; |
| return result; |
| } |
| |
| /* exp is signed so we can easy detect underflow */ |
| exp = a.parts.exp + b.parts.exp - FLOAT64_BIAS; |
| |
| frac1 = a.parts.fraction; |
| |
| if (a.parts.exp > 0) { |
| frac1 |= FLOAT64_HIDDEN_BIT_MASK; |
| } else { |
| ++exp; |
| }; |
| |
| frac2 = b.parts.fraction; |
| |
| if (b.parts.exp > 0) { |
| frac2 |= FLOAT64_HIDDEN_BIT_MASK; |
| } else { |
| ++exp; |
| }; |
| |
| frac1 <<= (64 - FLOAT64_FRACTION_SIZE - 1); |
| frac2 <<= (64 - FLOAT64_FRACTION_SIZE - 2); |
| |
| mul64integers(frac1, frac2, &frac1, &frac2); |
| |
| frac2 |= (frac1 != 0); |
| if (frac2 & (0x1ll << 62)) { |
| frac2 <<= 1; |
| exp--; |
| } |
| |
| result = finishFloat64(exp, frac2, result.parts.sign); |
| return result; |
| } |
| |
| /** Multiply two 64 bit numbers and return result in two parts |
| * @param a first operand |
| * @param b second operand |
| * @param lo lower part from result |
| * @param hi higher part of result |
| */ |
| void mul64integers(uint64_t a,uint64_t b, uint64_t *lo, uint64_t *hi) |
| { |
| uint64_t low, high, middle1, middle2; |
| uint32_t alow, blow; |
| |
| alow = a & 0xFFFFFFFF; |
| blow = b & 0xFFFFFFFF; |
| |
| a >>= 32; |
| b >>= 32; |
| |
| low = ((uint64_t)alow) * blow; |
| middle1 = a * blow; |
| middle2 = alow * b; |
| high = a * b; |
| |
| middle1 += middle2; |
| high += (((uint64_t)(middle1 < middle2)) << 32) + (middle1 >> 32); |
| middle1 <<= 32; |
| low += middle1; |
| high += (low < middle1); |
| *lo = low; |
| *hi = high; |
| |
| return; |
| } |
| |
| /** @} |
| */ |