| // |
| // Copyright (c) 2017 The Khronos Group Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| // |
| #include <stdint.h> |
| #include <math.h> |
| #include "fplib.h" |
| |
| #if !defined(FLT_MANT_DIG) |
| #define FLT_MANT_DIG 24 |
| #endif |
| #define as_float(x) (*((float *)(&x))) |
| #define as_long(x) (*((int64_t *)(&x))) |
| |
| static uint32_t clz(uint64_t value) |
| { |
| uint32_t num_zeros; |
| |
| for( num_zeros = 0; num_zeros < (sizeof(uint64_t)*8); num_zeros++) |
| { |
| if(0x8000000000000000 & (value << num_zeros)) |
| break; |
| } |
| return num_zeros; |
| } |
| |
| float qcom_s64_2_f32(int64_t data, bool sat, roundingMode rnd) |
| { |
| switch (rnd) { |
| case qcomRTZ: { |
| int sign = 0; |
| if (!data) |
| return 0.0f; |
| if (data < 0){ |
| data = - data; |
| sign = 1; |
| } |
| uint32_t exponent = (127 + 64 - clz(data) - 1) << (FLT_MANT_DIG - 1); //add 1 for the implied 1.0 in normalized fp32 numbers |
| int mantShift = 40 - clz(data); |
| uint32_t mantissa; |
| if (mantShift >= 0) |
| mantissa = (uint32_t)((uint64_t)data >> mantShift); |
| else |
| mantissa = (uint32_t)((uint64_t)data << -mantShift); |
| mantissa &= 0x7fffff;//mask off the leading 1 |
| |
| uint32_t result = exponent | mantissa; |
| if (sign) |
| result |= 0x80000000; |
| return as_float(result); |
| break; |
| } |
| case qcomRTE: return (float)(data); break; |
| case qcomRTP: { |
| int sign = 0; |
| int inExact = 0; |
| uint32_t f = 0xdf000000; |
| if (!data) |
| return 0.0f; |
| if (data == 0x8000000000000000) |
| return as_float(f); |
| if (data < 0){ |
| data = - data; |
| sign = 1; |
| } |
| uint32_t exponent = (127 + 64 - clz(data) - 1) << (FLT_MANT_DIG - 1); //add 1 for the implied 1.0 in normalized fp32 numbers |
| int mantShift = 40 - clz(data); |
| uint32_t mantissa; |
| if (mantShift >= 0){ |
| uint64_t temp = (uint64_t)data >> mantShift; |
| uint64_t mask = (1 << mantShift) - 1; |
| if ((temp << mantShift) != data) |
| inExact = 1; |
| mantissa = (uint32_t)temp; |
| } |
| else |
| { |
| mantissa = (uint32_t)((uint64_t)data << -mantShift); |
| } |
| mantissa &= 0x7fffff;//mask off the leading 1 |
| |
| uint32_t result = exponent | mantissa; |
| if (sign) |
| result |= 0x80000000; |
| if (sign) |
| return as_float(result); // for negative inputs return rtz results |
| else |
| { |
| if(inExact) |
| { // for positive inputs return higher next fp |
| uint32_t high_float = 0x7f7fffff; |
| return nextafterf(as_float(result), as_float(high_float)); // could be simplified with some inc and carry operation |
| } |
| else |
| return as_float(result); |
| } |
| } |
| break; |
| case qcomRTN: { |
| int sign = 0; |
| int inExact = 0; |
| uint32_t f = 0xdf000000; |
| if (!data) |
| return 0.0f; |
| if (data == 0x8000000000000000) |
| return as_float(f); |
| if (data < 0){ |
| data = - data; |
| sign = 1; |
| } |
| uint32_t exponent = (127 + 64 - clz(data) - 1) << (FLT_MANT_DIG - 1); //add 1 for the implied 1.0 in normalized fp32 numbers |
| int mantShift = 40 - clz(data); |
| uint32_t mantissa; |
| if (mantShift >= 0){ |
| uint64_t temp = (uint64_t)data >> mantShift; |
| uint64_t mask = (1 << mantShift) - 1; |
| if (temp << mantShift != data) |
| inExact = 1; |
| mantissa = (uint32_t)temp; |
| } |
| else |
| mantissa = (uint32_t)((uint64_t)data << -mantShift); |
| mantissa &= 0x7fffff;//mask off the leading 1 |
| |
| uint32_t result = exponent | mantissa; |
| if (sign) |
| result |= 0x80000000; |
| if (!sign) |
| return as_float(result); // for positive inputs return RTZ result |
| else{ |
| if(inExact){ // for negative inputs find the lower next fp number |
| uint32_t low_float = 0xff7fffff; |
| return nextafterf(as_float(result), as_float(low_float)); // could be simplified with some inc and carry operation |
| } |
| else |
| return as_float(result); |
| } |
| } |
| case qcomRoundingModeCount: { |
| break; // Avoid build error for unhandled enum value |
| } |
| } |
| return 0.0f; |
| } |
| |
| float qcom_u64_2_f32(uint64_t data, bool sat, roundingMode rnd) |
| { |
| switch (rnd) { |
| case qcomRTZ: { |
| if (!data) |
| return 0.0f; |
| uint32_t exponent = (127 + 64 - clz(data) - 1) << (FLT_MANT_DIG - 1); //add 1 for the implied 1.0 in normalized fp32 numbers |
| int mantShift = 40 - clz(data); |
| uint32_t mantissa; |
| if (mantShift >= 0) |
| mantissa = (uint32_t)(data >> mantShift); |
| else |
| mantissa = (uint32_t)(data << -mantShift); |
| mantissa &= 0x7fffff;//mask off the leading 1 |
| |
| uint32_t result = exponent | mantissa; |
| return as_float(result); |
| break; |
| } |
| case qcomRTE: return (float)(data); break; |
| case qcomRTP: { |
| int inExact = 0; |
| if (!data) |
| return 0.0f; |
| uint32_t exponent = (127 + 64 - clz(data) - 1) << (FLT_MANT_DIG - 1); //add 1 for the implied 1.0 in normalized fp32 numbers |
| int mantShift = 40 - clz(data); |
| uint32_t mantissa; |
| if (mantShift >= 0){ |
| uint64_t temp = data >> mantShift; |
| uint64_t mask = (1 << mantShift) - 1; |
| if (temp << mantShift != data) |
| inExact = 1; |
| mantissa = (uint32_t)temp; |
| } |
| else |
| mantissa = (uint32_t)(data << -mantShift); |
| mantissa &= 0x7fffff;//mask off the leading 1 |
| |
| uint32_t result = exponent | mantissa; |
| if(inExact){ // for positive inputs return higher next fp |
| uint32_t high_float = 0x7f7fffff; |
| return nextafterf(as_float(result), as_float(high_float)); // could be simplified with some inc and carry operation |
| } |
| else |
| return as_float(result); |
| } |
| case qcomRTN: { |
| int inExact = 0; |
| if (!data) |
| return 0.0f; |
| uint32_t exponent = (127 + 64 - clz(data) - 1) << (FLT_MANT_DIG - 1); //add 1 for the implied 1.0 in normalized fp32 numbers |
| int mantShift = 40 - clz(data); |
| uint32_t mantissa; |
| if (mantShift >= 0){ |
| uint64_t temp = (uint64_t)data >> mantShift; |
| uint64_t mask = (1 << mantShift) - 1; |
| if (temp << mantShift != data) |
| inExact = 1; |
| mantissa = (uint32_t)temp; |
| } |
| else |
| mantissa = (uint32_t)((uint64_t)data << -mantShift); |
| mantissa &= 0x7fffff;//mask off the leading 1 |
| |
| uint32_t result = exponent | mantissa; |
| return as_float(result); // for positive inputs return RTZ result |
| } |
| case qcomRoundingModeCount: { |
| break; // Avoid build error for unhandled enum value |
| } |
| } |
| return 0.0f; |
| } |
