1 //===-- lib/floatunsisf.c - uint -> single-precision conversion ---*- C -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This file implements unsigned integer to single-precision conversion for the 11 // compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even 12 // mode. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #define SINGLE_PRECISION 17 #include "fp_lib.h" 18 19 #include "int_lib.h" 20 21 COMPILER_RT_ABI fp_t __floatunsisf(unsigned int a)22__floatunsisf(unsigned int a) { 23 24 const int aWidth = sizeof a * CHAR_BIT; 25 26 // Handle zero as a special case to protect clz 27 if (a == 0) return fromRep(0); 28 29 // Exponent of (fp_t)a is the width of abs(a). 30 const int exponent = (aWidth - 1) - __builtin_clz(a); 31 rep_t result; 32 33 // Shift a into the significand field, rounding if it is a right-shift 34 if (exponent <= significandBits) { 35 const int shift = significandBits - exponent; 36 result = (rep_t)a << shift ^ implicitBit; 37 } else { 38 const int shift = exponent - significandBits; 39 result = (rep_t)a >> shift ^ implicitBit; 40 rep_t round = (rep_t)a << (typeWidth - shift); 41 if (round > signBit) result++; 42 if (round == signBit) result += result & 1; 43 } 44 45 // Insert the exponent 46 result += (rep_t)(exponent + exponentBias) << significandBits; 47 return fromRep(result); 48 } 49 50 #if defined(__ARM_EABI__) 51 #if defined(COMPILER_RT_ARMHF_TARGET) __aeabi_ui2f(unsigned int a)52AEABI_RTABI fp_t __aeabi_ui2f(unsigned int a) { 53 return __floatunsisf(a); 54 } 55 #else 56 AEABI_RTABI fp_t __aeabi_ui2f(unsigned int a) COMPILER_RT_ALIAS(__floatunsisf); 57 #endif 58 #endif 59