minix/sys/external/bsd/compiler_rt/dist/lib/floatunsisf.c
Lionel Sambuc 4684ddb6aa LLVM Minix changes
- import libcxx
 - reduce targets to the one when compiled as a tools

Change-Id: Iabb8427f80ff8e89463559a28bcb8b4f2bdbc496
2014-07-28 17:05:59 +02:00

49 lines
1.6 KiB
C

//===-- lib/floatunsisf.c - uint -> single-precision conversion ---*- C -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements unsigned integer to single-precision conversion for the
// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
// mode.
//
//===----------------------------------------------------------------------===//
#define SINGLE_PRECISION
#include "fp_lib.h"
#include "int_lib.h"
ARM_EABI_FNALIAS(ui2f, floatunsisf)
fp_t __floatunsisf(unsigned int a) {
const int aWidth = sizeof a * CHAR_BIT;
// Handle zero as a special case to protect clz
if (a == 0) return fromRep(0);
// Exponent of (fp_t)a is the width of abs(a).
const int exponent = (aWidth - 1) - __builtin_clz(a);
rep_t result;
// Shift a into the significand field, rounding if it is a right-shift
if (exponent <= significandBits) {
const int shift = significandBits - exponent;
result = (rep_t)a << shift ^ implicitBit;
} else {
const int shift = exponent - significandBits;
result = (rep_t)a >> shift ^ implicitBit;
rep_t round = (rep_t)a << (typeWidth - shift);
if (round > signBit) result++;
if (round == signBit) result += result & 1;
}
// Insert the exponent
result += (rep_t)(exponent + exponentBias) << significandBits;
return fromRep(result);
}