1 //===-- lib/floatunsisf.c - uint -> single-precision conversion ---*- C -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements unsigned integer to single-precision conversion for the 10 // compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even 11 // mode. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #define SINGLE_PRECISION 16 #include "fp_lib.h" 17 18 #include "int_lib.h" 19 20 COMPILER_RT_ABI fp_t __floatunsisf(unsigned int a) { 21 22 const int aWidth = sizeof a * CHAR_BIT; 23 24 // Handle zero as a special case to protect clz 25 if (a == 0) 26 return fromRep(0); 27 28 // Exponent of (fp_t)a is the width of abs(a). 29 const int exponent = (aWidth - 1) - __builtin_clz(a); 30 rep_t result; 31 32 // Shift a into the significand field, rounding if it is a right-shift 33 if (exponent <= significandBits) { 34 const int shift = significandBits - exponent; 35 result = (rep_t)a << shift ^ implicitBit; 36 } else { 37 const int shift = exponent - significandBits; 38 result = (rep_t)a >> shift ^ implicitBit; 39 rep_t round = (rep_t)a << (typeWidth - shift); 40 if (round > signBit) 41 result++; 42 if (round == signBit) 43 result += result & 1; 44 } 45 46 // Insert the exponent 47 result += (rep_t)(exponent + exponentBias) << significandBits; 48 return fromRep(result); 49 } 50 51 #if defined(__ARM_EABI__) 52 #if defined(COMPILER_RT_ARMHF_TARGET) 53 AEABI_RTABI fp_t __aeabi_ui2f(unsigned int a) { return __floatunsisf(a); } 54 #else 55 COMPILER_RT_ALIAS(__floatunsisf, __aeabi_ui2f) 56 #endif 57 #endif 58