fp_mode.c
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//===----- lib/aarch64/fp_mode.c - Floaing-point mode utilities ---*- 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
//
//===----------------------------------------------------------------------===//
#include <stdint.h>
#include "../fp_mode.h"
#define AARCH64_TONEAREST 0x0
#define AARCH64_UPWARD 0x1
#define AARCH64_DOWNWARD 0x2
#define AARCH64_TOWARDZERO 0x3
#define AARCH64_RMODE_MASK (AARCH64_TONEAREST | AARCH64_UPWARD | \
AARCH64_DOWNWARD | AARCH64_TOWARDZERO)
#define AARCH64_RMODE_SHIFT 22
#define AARCH64_INEXACT 0x10
#ifndef __ARM_FP
// For soft float targets, allow changing rounding mode by overriding the weak
// __aarch64_fe_default_rmode symbol.
FE_ROUND_MODE __attribute__((weak)) __aarch64_fe_default_rmode = FE_TONEAREST;
#endif
FE_ROUND_MODE __fe_getround() {
#ifdef __ARM_FP
uint64_t fpcr;
__asm__ __volatile__("mrs %0, fpcr" : "=r" (fpcr));
fpcr = fpcr >> AARCH64_RMODE_SHIFT & AARCH64_RMODE_MASK;
switch (fpcr) {
case AARCH64_UPWARD:
return FE_UPWARD;
case AARCH64_DOWNWARD:
return FE_DOWNWARD;
case AARCH64_TOWARDZERO:
return FE_TOWARDZERO;
case AARCH64_TONEAREST:
default:
return FE_TONEAREST;
}
#else
return __aarch64_fe_default_rmode;
#endif
}
int __fe_raise_inexact() {
#ifdef __ARM_FP
uint64_t fpsr;
__asm__ __volatile__("mrs %0, fpsr" : "=r" (fpsr));
__asm__ __volatile__("msr fpsr, %0" : : "ri" (fpsr | AARCH64_INEXACT));
return 0;
#else
return 0;
#endif
}