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40 lines
1.1 KiB
40 lines
1.1 KiB
7 months ago
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//===----- lib/i386/fp_mode.c - Floaing-point mode utilities -----*- C -*-====//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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#include "../fp_mode.h"
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#define X87_TONEAREST 0x0000
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#define X87_DOWNWARD 0x0400
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#define X87_UPWARD 0x0800
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#define X87_TOWARDZERO 0x0c00
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#define X87_RMODE_MASK (X87_TONEAREST | X87_UPWARD | X87_DOWNWARD | X87_TOWARDZERO)
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FE_ROUND_MODE __fe_getround() {
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// Assume that the rounding mode state for the fpu agrees with the SSE unit.
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unsigned short cw;
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__asm__ __volatile__ ("fnstcw %0" : "=m" (cw));
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switch (cw & X87_RMODE_MASK) {
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case X87_TONEAREST:
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return FE_TONEAREST;
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case X87_DOWNWARD:
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return FE_DOWNWARD;
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case X87_UPWARD:
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return FE_UPWARD;
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case X87_TOWARDZERO:
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return FE_TOWARDZERO;
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}
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return FE_TONEAREST;
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}
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int __fe_raise_inexact() {
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float f = 1.0f, g = 3.0f;
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__asm__ __volatile__ ("fdivs %1" : "+t" (f) : "m" (g));
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return 0;
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}
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