llvm-capstone/compiler-rt/lib/builtins/floatsitf.c
Petr Hosek 082b89b25f [builtins] Reformat builtins with clang-format
Update formatting to use the LLVM style.

This is part of the cleanup proposed in "[RFC] compiler-rt builtins
cleanup and refactoring".

Differential Revision: https://reviews.llvm.org/D60351

llvm-svn: 359410
2019-04-28 21:53:32 +00:00

50 lines
1.5 KiB
C

//===-- lib/floatsitf.c - integer -> 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 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 __floatsitf(int a) {
const int aWidth = sizeof a * CHAR_BIT;
// Handle zero as a special case to protect clz
if (a == 0)
return fromRep(0);
// All other cases begin by extracting the sign and absolute value of a
rep_t sign = 0;
unsigned aAbs = (unsigned)a;
if (a < 0) {
sign = signBit;
aAbs = ~(unsigned)a + 1U;
}
// Exponent of (fp_t)a is the width of abs(a).
const int exponent = (aWidth - 1) - __builtin_clz(aAbs);
rep_t result;
// Shift a into the significand field and clear the implicit bit.
const int shift = significandBits - exponent;
result = (rep_t)aAbs << shift ^ implicitBit;
// Insert the exponent
result += (rep_t)(exponent + exponentBias) << significandBits;
// Insert the sign bit and return
return fromRep(result | sign);
}
#endif