44 lines
1.4 KiB
C
44 lines
1.4 KiB
C
/* clang-format off */
|
|
//===-- lib/floatunsitf.c - uint -> quad-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 quad-precision conversion for the
|
|
// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
|
|
// mode.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
STATIC_YOINK("huge_compiler_rt_license");
|
|
|
|
#define QUAD_PRECISION
|
|
#include "third_party/compiler_rt/fp_lib.inc"
|
|
|
|
#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
|
|
COMPILER_RT_ABI fp_t __floatunsitf(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 and clear the implicit bit.
|
|
const int shift = significandBits - exponent;
|
|
result = (rep_t)a << shift ^ implicitBit;
|
|
|
|
// Insert the exponent
|
|
result += (rep_t)(exponent + exponentBias) << significandBits;
|
|
return fromRep(result);
|
|
}
|
|
|
|
#endif
|