61 lines · c
1//===----- lib/arm/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-exception6//7//===----------------------------------------------------------------------===//8 9#include <stdint.h>10 11#include "../fp_mode.h"12 13#define ARM_TONEAREST 0x014#define ARM_UPWARD 0x115#define ARM_DOWNWARD 0x216#define ARM_TOWARDZERO 0x317#define ARM_RMODE_MASK (ARM_TONEAREST | ARM_UPWARD | \18 ARM_DOWNWARD | ARM_TOWARDZERO)19#define ARM_RMODE_SHIFT 2220 21#define ARM_INEXACT 0x1022 23#ifndef __ARM_FP24// For soft float targets, allow changing rounding mode by overriding the weak25// __arm_fe_default_rmode symbol.26CRT_FE_ROUND_MODE __attribute__((weak)) __arm_fe_default_rmode =27 CRT_FE_TONEAREST;28#endif29 30CRT_FE_ROUND_MODE __fe_getround(void) {31#ifdef __ARM_FP32 uint32_t fpscr;33 __asm__ __volatile__("vmrs %0, fpscr" : "=r" (fpscr));34 fpscr = fpscr >> ARM_RMODE_SHIFT & ARM_RMODE_MASK;35 switch (fpscr) {36 case ARM_UPWARD:37 return CRT_FE_UPWARD;38 case ARM_DOWNWARD:39 return CRT_FE_DOWNWARD;40 case ARM_TOWARDZERO:41 return CRT_FE_TOWARDZERO;42 case ARM_TONEAREST:43 default:44 return CRT_FE_TONEAREST;45 }46#else47 return __arm_fe_default_rmode;48#endif49}50 51int __fe_raise_inexact(void) {52#ifdef __ARM_FP53 uint32_t fpscr;54 __asm__ __volatile__("vmrs %0, fpscr" : "=r" (fpscr));55 __asm__ __volatile__("vmsr fpscr, %0" : : "ri" (fpscr | ARM_INEXACT));56 return 0;57#else58 return 0;59#endif60}61