| //===-- 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; |
| if (a < 0) { |
| sign = signBit; |
| a = -a; |
| } |
| |
| // 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. 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)(su_int)a << 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 |