1 //===-- lib/floatunsisf.c - uint -> single-precision conversion ---*- C -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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
14 //===----------------------------------------------------------------------===//
16 #define SINGLE_PRECISION
21 ARM_EABI_FNALIAS(ui2f, floatunsisf)
24 __floatunsisf(unsigned int a) {
26 const int aWidth = sizeof a * CHAR_BIT;
28 // Handle zero as a special case to protect clz
29 if (a == 0) return fromRep(0);
31 // Exponent of (fp_t)a is the width of abs(a).
32 const int exponent = (aWidth - 1) - __builtin_clz(a);
35 // Shift a into the significand field, rounding if it is a right-shift
36 if (exponent <= significandBits) {
37 const int shift = significandBits - exponent;
38 result = (rep_t)a << shift ^ implicitBit;
40 const int shift = exponent - significandBits;
41 result = (rep_t)a >> shift ^ implicitBit;
42 rep_t round = (rep_t)a << (typeWidth - shift);
43 if (round > signBit) result++;
44 if (round == signBit) result += result & 1;
47 // Insert the exponent
48 result += (rep_t)(exponent + exponentBias) << significandBits;
49 return fromRep(result);