4bcd2588a9
`__builtin_c[tl]z` accepts `unsigned int` argument that is not always the same as uint32_t. For example, `unsigned int` is uint16_t on MSP430. Reviewed By: aykevl Differential Revision: https://reviews.llvm.org/D86547
41 lines
1.3 KiB
C
41 lines
1.3 KiB
C
//===-- lib/floatunsitf.c - uint -> quad-precision conversion -----*- C -*-===//
|
|
//
|
|
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|
|
// See https://llvm.org/LICENSE.txt for license information.
|
|
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// 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.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#define QUAD_PRECISION
|
|
#include "fp_lib.h"
|
|
|
|
#if defined(CRT_HAS_128BIT) && defined(CRT_LDBL_128BIT)
|
|
COMPILER_RT_ABI fp_t __floatunsitf(su_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) - clzsi(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
|