1*0b57cec5SDimitry Andric //===-- lib/floatunsisf.c - uint -> single-precision conversion ---*- C -*-===// 2*0b57cec5SDimitry Andric // 3*0b57cec5SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*0b57cec5SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*0b57cec5SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*0b57cec5SDimitry Andric // 7*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 8*0b57cec5SDimitry Andric // 9*0b57cec5SDimitry Andric // This file implements unsigned integer to single-precision conversion for the 10*0b57cec5SDimitry Andric // compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even 11*0b57cec5SDimitry Andric // mode. 12*0b57cec5SDimitry Andric // 13*0b57cec5SDimitry Andric //===----------------------------------------------------------------------===// 14*0b57cec5SDimitry Andric 15*0b57cec5SDimitry Andric #define SINGLE_PRECISION 16*0b57cec5SDimitry Andric #include "fp_lib.h" 17*0b57cec5SDimitry Andric 18*0b57cec5SDimitry Andric #include "int_lib.h" 19*0b57cec5SDimitry Andric 20*0b57cec5SDimitry Andric COMPILER_RT_ABI fp_t __floatunsisf(unsigned int a) { 21*0b57cec5SDimitry Andric 22*0b57cec5SDimitry Andric const int aWidth = sizeof a * CHAR_BIT; 23*0b57cec5SDimitry Andric 24*0b57cec5SDimitry Andric // Handle zero as a special case to protect clz 25*0b57cec5SDimitry Andric if (a == 0) 26*0b57cec5SDimitry Andric return fromRep(0); 27*0b57cec5SDimitry Andric 28*0b57cec5SDimitry Andric // Exponent of (fp_t)a is the width of abs(a). 29*0b57cec5SDimitry Andric const int exponent = (aWidth - 1) - __builtin_clz(a); 30*0b57cec5SDimitry Andric rep_t result; 31*0b57cec5SDimitry Andric 32*0b57cec5SDimitry Andric // Shift a into the significand field, rounding if it is a right-shift 33*0b57cec5SDimitry Andric if (exponent <= significandBits) { 34*0b57cec5SDimitry Andric const int shift = significandBits - exponent; 35*0b57cec5SDimitry Andric result = (rep_t)a << shift ^ implicitBit; 36*0b57cec5SDimitry Andric } else { 37*0b57cec5SDimitry Andric const int shift = exponent - significandBits; 38*0b57cec5SDimitry Andric result = (rep_t)a >> shift ^ implicitBit; 39*0b57cec5SDimitry Andric rep_t round = (rep_t)a << (typeWidth - shift); 40*0b57cec5SDimitry Andric if (round > signBit) 41*0b57cec5SDimitry Andric result++; 42*0b57cec5SDimitry Andric if (round == signBit) 43*0b57cec5SDimitry Andric result += result & 1; 44*0b57cec5SDimitry Andric } 45*0b57cec5SDimitry Andric 46*0b57cec5SDimitry Andric // Insert the exponent 47*0b57cec5SDimitry Andric result += (rep_t)(exponent + exponentBias) << significandBits; 48*0b57cec5SDimitry Andric return fromRep(result); 49*0b57cec5SDimitry Andric } 50*0b57cec5SDimitry Andric 51*0b57cec5SDimitry Andric #if defined(__ARM_EABI__) 52*0b57cec5SDimitry Andric #if defined(COMPILER_RT_ARMHF_TARGET) 53*0b57cec5SDimitry Andric AEABI_RTABI fp_t __aeabi_ui2f(unsigned int a) { return __floatunsisf(a); } 54*0b57cec5SDimitry Andric #else 55*0b57cec5SDimitry Andric COMPILER_RT_ALIAS(__floatunsisf, __aeabi_ui2f) 56*0b57cec5SDimitry Andric #endif 57*0b57cec5SDimitry Andric #endif 58