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1//===-- lib/floatsidf.c - integer -> double-precision conversion --*- C -*-===//2//3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.4// See https://llvm.org/LICENSE.txt for license information.5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception6//7//===----------------------------------------------------------------------===//8//9// This file implements integer to double-precision conversion for the10// compiler-rt library in the IEEE-754 default round-to-nearest, ties-to-even11// mode.12//13//===----------------------------------------------------------------------===//14 15#define DOUBLE_PRECISION16#include "fp_lib.h"17 18#include "int_lib.h"19 20COMPILER_RT_ABI fp_t __floatsidf(si_int a) {21 22 const int aWidth = sizeof a * CHAR_BIT;23 24 // Handle zero as a special case to protect clz25 if (a == 0)26 return fromRep(0);27 28 // All other cases begin by extracting the sign and absolute value of a29 rep_t sign = 0;30 su_int aAbs = (su_int)a;31 if (a < 0) {32 sign = signBit;33 aAbs = -aAbs;34 }35 36 // Exponent of (fp_t)a is the width of abs(a).37 const int exponent = (aWidth - 1) - clzsi(aAbs);38 rep_t result;39 40 // Shift a into the significand field and clear the implicit bit. Extra41 // cast to unsigned int is necessary to get the correct behavior for42 // the input INT_MIN.43 const int shift = significandBits - exponent;44 result = (rep_t)aAbs << shift ^ implicitBit;45 46 // Insert the exponent47 result += (rep_t)(exponent + exponentBias) << significandBits;48 // Insert the sign bit and return49 return fromRep(result | sign);50}51 52#if defined(__ARM_EABI__)53#if defined(COMPILER_RT_ARMHF_TARGET)54AEABI_RTABI fp_t __aeabi_i2d(si_int a) { return __floatsidf(a); }55#else56COMPILER_RT_ALIAS(__floatsidf, __aeabi_i2d)57#endif58#endif59