1*68d75effSDimitry Andric //===----- lib/arm/fp_mode.c - Floaing-point mode utilities -------*- C -*-===// 2*68d75effSDimitry Andric // 3*68d75effSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*68d75effSDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 5*68d75effSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*68d75effSDimitry Andric // 7*68d75effSDimitry Andric //===----------------------------------------------------------------------===// 8*68d75effSDimitry Andric 9*68d75effSDimitry Andric #include <stdint.h> 10*68d75effSDimitry Andric 11*68d75effSDimitry Andric #include "../fp_mode.h" 12*68d75effSDimitry Andric 13*68d75effSDimitry Andric #define ARM_TONEAREST 0x0 14*68d75effSDimitry Andric #define ARM_UPWARD 0x1 15*68d75effSDimitry Andric #define ARM_DOWNWARD 0x2 16*68d75effSDimitry Andric #define ARM_TOWARDZERO 0x3 17*68d75effSDimitry Andric #define ARM_RMODE_MASK (ARM_TONEAREST | ARM_UPWARD | \ 18*68d75effSDimitry Andric ARM_DOWNWARD | ARM_TOWARDZERO) 19*68d75effSDimitry Andric #define ARM_RMODE_SHIFT 22 20*68d75effSDimitry Andric 21*68d75effSDimitry Andric #define ARM_INEXACT 0x1000 22*68d75effSDimitry Andric 23*68d75effSDimitry Andric #ifndef __ARM_FP 24*68d75effSDimitry Andric // For soft float targets, allow changing rounding mode by overriding the weak 25*68d75effSDimitry Andric // __arm_fe_default_rmode symbol. 26*68d75effSDimitry Andric FE_ROUND_MODE __attribute__((weak)) __arm_fe_default_rmode = FE_TONEAREST; 27*68d75effSDimitry Andric #endif 28*68d75effSDimitry Andric 29*68d75effSDimitry Andric FE_ROUND_MODE __fe_getround() { 30*68d75effSDimitry Andric #ifdef __ARM_FP 31*68d75effSDimitry Andric uint32_t fpscr; 32*68d75effSDimitry Andric __asm__ __volatile__("vmrs %0, fpscr" : "=r" (fpscr)); 33*68d75effSDimitry Andric fpscr = fpscr >> ARM_RMODE_SHIFT & ARM_RMODE_MASK; 34*68d75effSDimitry Andric switch (fpscr) { 35*68d75effSDimitry Andric case ARM_UPWARD: 36*68d75effSDimitry Andric return FE_UPWARD; 37*68d75effSDimitry Andric case ARM_DOWNWARD: 38*68d75effSDimitry Andric return FE_DOWNWARD; 39*68d75effSDimitry Andric case ARM_TOWARDZERO: 40*68d75effSDimitry Andric return FE_TOWARDZERO; 41*68d75effSDimitry Andric case ARM_TONEAREST: 42*68d75effSDimitry Andric default: 43*68d75effSDimitry Andric return FE_TONEAREST; 44*68d75effSDimitry Andric } 45*68d75effSDimitry Andric #else 46*68d75effSDimitry Andric return __arm_fe_default_rmode; 47*68d75effSDimitry Andric #endif 48*68d75effSDimitry Andric } 49*68d75effSDimitry Andric 50*68d75effSDimitry Andric int __fe_raise_inexact() { 51*68d75effSDimitry Andric #ifdef __ARM_FP 52*68d75effSDimitry Andric uint32_t fpscr; 53*68d75effSDimitry Andric __asm__ __volatile__("vmrs %0, fpscr" : "=r" (fpscr)); 54*68d75effSDimitry Andric __asm__ __volatile__("vmsr fpscr, %0" : : "ri" (fpscr | ARM_INEXACT)); 55*68d75effSDimitry Andric return 0; 56*68d75effSDimitry Andric #else 57*68d75effSDimitry Andric return 0; 58*68d75effSDimitry Andric #endif 59*68d75effSDimitry Andric } 60