1 //===-- lib/floatunsidf.c - uint -> double-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 double-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 DOUBLE_PRECISION 17 #include "fp_lib.h" 18 19 #include "int_lib.h" 20 21 COMPILER_RT_ABI fp_t __floatunsidf(unsigned int a)22__floatunsidf(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 and clear the implicit bit. 34 const int shift = significandBits - exponent; 35 result = (rep_t)a << shift ^ implicitBit; 36 37 // Insert the exponent 38 result += (rep_t)(exponent + exponentBias) << significandBits; 39 return fromRep(result); 40 } 41 42 #if defined(__ARM_EABI__) 43 #if defined(COMPILER_RT_ARMHF_TARGET) __aeabi_ui2d(unsigned int a)44AEABI_RTABI fp_t __aeabi_ui2d(unsigned int a) { 45 return __floatunsidf(a); 46 } 47 #else 48 AEABI_RTABI fp_t __aeabi_ui2d(unsigned int a) COMPILER_RT_ALIAS(__floatunsidf); 49 #endif 50 #endif 51