1//===----- lib/aarch64/fp_mode.c - Floaing-point mode utilities ---*- 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#include <stdint.h> 10 11#include "../fp_mode.h" 12 13#define AARCH64_TONEAREST 0x0 14#define AARCH64_UPWARD 0x1 15#define AARCH64_DOWNWARD 0x2 16#define AARCH64_TOWARDZERO 0x3 17#define AARCH64_RMODE_MASK (AARCH64_TONEAREST | AARCH64_UPWARD | \ 18 AARCH64_DOWNWARD | AARCH64_TOWARDZERO) 19#define AARCH64_RMODE_SHIFT 22 20 21#define AARCH64_INEXACT 0x10 22 23#ifndef __ARM_FP 24// For soft float targets, allow changing rounding mode by overriding the weak 25// __aarch64_fe_default_rmode symbol. 26FE_ROUND_MODE __attribute__((weak)) __aarch64_fe_default_rmode = FE_TONEAREST; 27#endif 28 29FE_ROUND_MODE __fe_getround() { 30#ifdef __ARM_FP 31 uint64_t fpcr; 32 __asm__ __volatile__("mrs %0, fpcr" : "=r" (fpcr)); 33 fpcr = fpcr >> AARCH64_RMODE_SHIFT & AARCH64_RMODE_MASK; 34 switch (fpcr) { 35 case AARCH64_UPWARD: 36 return FE_UPWARD; 37 case AARCH64_DOWNWARD: 38 return FE_DOWNWARD; 39 case AARCH64_TOWARDZERO: 40 return FE_TOWARDZERO; 41 case AARCH64_TONEAREST: 42 default: 43 return FE_TONEAREST; 44 } 45#else 46 return __aarch64_fe_default_rmode; 47#endif 48} 49 50int __fe_raise_inexact() { 51#ifdef __ARM_FP 52 uint64_t fpsr; 53 __asm__ __volatile__("mrs %0, fpsr" : "=r" (fpsr)); 54 __asm__ __volatile__("msr fpsr, %0" : : "ri" (fpsr | AARCH64_INEXACT)); 55 return 0; 56#else 57 return 0; 58#endif 59} 60