forked from OSchip/llvm-project
40 lines
1.4 KiB
C
40 lines
1.4 KiB
C
//===-- lib/fixdfsi.c - Double-precision -> integer 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 float to unsigned integer conversion for the
|
|
// compiler-rt library.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "fp_lib.h"
|
|
|
|
static __inline fixuint_t __fixuint(fp_t a) {
|
|
// Break a into sign, exponent, significand
|
|
const rep_t aRep = toRep(a);
|
|
const rep_t aAbs = aRep & absMask;
|
|
const int sign = aRep & signBit ? -1 : 1;
|
|
const int exponent = (aAbs >> significandBits) - exponentBias;
|
|
const rep_t significand = (aAbs & significandMask) | implicitBit;
|
|
|
|
// If either the value or the exponent is negative, the result is zero.
|
|
if (sign == -1 || exponent < 0)
|
|
return 0;
|
|
|
|
// If the value is too large for the integer type, saturate.
|
|
if ((unsigned)exponent >= sizeof(fixuint_t) * CHAR_BIT)
|
|
return ~(fixuint_t)0;
|
|
|
|
// If 0 <= exponent < significandBits, right shift to get the result.
|
|
// Otherwise, shift left.
|
|
if (exponent < significandBits)
|
|
return significand >> (significandBits - exponent);
|
|
else
|
|
return (fixuint_t)significand << (exponent - significandBits);
|
|
}
|