fp_fixuint_impl.inc (1876B)
1 //===-- lib/fixdfsi.c - Double-precision -> integer 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-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file implements float to unsigned integer conversion for the 10 // compiler-rt library. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "fp_lib.h" 15 16 #ifndef FP_FIX_SUFFIX 17 #error "fp_fixuint_impl.inc: FP_FIX_SUFFIX must be defined before #include" 18 #endif 19 20 #ifndef FP_FIX_IMPL_PASTE_ 21 #define FP_FIX_IMPL_PASTE_(a, b) a##_##b 22 #define FP_FIX_IMPL_PASTE(a, b) FP_FIX_IMPL_PASTE_(a, b) 23 #endif 24 25 #ifdef __fixuint 26 #undef __fixuint 27 #endif 28 #define __fixuint FP_FIX_IMPL_PASTE(__fixuint, FP_FIX_SUFFIX) 29 30 static inline fixuint_t __fixuint(fp_t a) { 31 // Break a into sign, exponent, significand parts. 32 const rep_t aRep = toRep(a); 33 const rep_t aAbs = aRep & absMask; 34 const int sign = aRep & signBit ? -1 : 1; 35 const int exponent = (aAbs >> significandBits) - exponentBias; 36 const rep_t significand = (aAbs & significandMask) | implicitBit; 37 38 // If either the value or the exponent is negative, the result is zero. 39 if (sign == -1 || exponent < 0) 40 return 0; 41 42 // If the value is too large for the integer type, saturate. 43 if ((unsigned)exponent >= sizeof(fixuint_t) * CHAR_BIT) 44 return ~(fixuint_t)0; 45 46 // If 0 <= exponent < significandBits, right shift to get the result. 47 // Otherwise, shift left. 48 if (exponent < significandBits) 49 return significand >> (significandBits - exponent); 50 else 51 return (fixuint_t)significand << (exponent - significandBits); 52 } 53 54 // FP_FIX_SUFFIX, fixuint_t intentionally left defined; see fp_fixint_impl.inc.