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//===-- lib/floatsidf.c - integer -> double-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 double-precision conversion for the
// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even
// mode.
//
//===----------------------------------------------------------------------===//
#define DOUBLE_PRECISION
#include "fp_lib.h"
#include "int_lib.h"
COMPILER_RT_ABI fp_t __floatsidf(si_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;
su_int aAbs = (su_int)a;
if (a < 0) {
sign = signBit;
aAbs = -aAbs;
}
// Exponent of (fp_t)a is the width of abs(a).
const int exponent = (aWidth - 1) - clzsi(aAbs);
rep_t result;
// Shift a into the significand field and clear the implicit bit. Extra
// cast to unsigned int is necessary to get the correct behavior for
// the input INT_MIN.
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);
}
#if defined(__ARM_EABI__)
#if defined(COMPILER_RT_ARMHF_TARGET)
AEABI_RTABI fp_t __aeabi_i2d(si_int a) { return __floatsidf(a); }
#else
COMPILER_RT_ALIAS(__floatsidf, __aeabi_i2d)
#endif
#endif
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