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Based on 1 normalized pattern(s): this program is free software you can distribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin st fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 33 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081038.563233189@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
97 lines
1.9 KiB
C
97 lines
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* IEEE754 floating point arithmetic
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* double precision: common utilities
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*/
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/*
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* MIPS floating point support
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* Copyright (C) 1994-2000 Algorithmics Ltd.
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*/
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#include "ieee754dp.h"
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int ieee754dp_tint(union ieee754dp x)
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{
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u64 residue;
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int round;
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int sticky;
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int odd;
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COMPXDP;
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ieee754_clearcx();
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EXPLODEXDP;
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FLUSHXDP;
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switch (xc) {
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case IEEE754_CLASS_SNAN:
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case IEEE754_CLASS_QNAN:
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ieee754_setcx(IEEE754_INVALID_OPERATION);
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return ieee754si_indef();
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case IEEE754_CLASS_INF:
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ieee754_setcx(IEEE754_INVALID_OPERATION);
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return ieee754si_overflow(xs);
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case IEEE754_CLASS_ZERO:
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return 0;
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case IEEE754_CLASS_DNORM:
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case IEEE754_CLASS_NORM:
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break;
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}
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if (xe > 31) {
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/* Set invalid. We will only use overflow for floating
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point overflow */
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ieee754_setcx(IEEE754_INVALID_OPERATION);
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return ieee754si_overflow(xs);
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}
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/* oh gawd */
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if (xe > DP_FBITS) {
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xm <<= xe - DP_FBITS;
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} else if (xe < DP_FBITS) {
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if (xe < -1) {
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residue = xm;
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round = 0;
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sticky = residue != 0;
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xm = 0;
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} else {
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residue = xm << (64 - DP_FBITS + xe);
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round = (residue >> 63) != 0;
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sticky = (residue << 1) != 0;
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xm >>= DP_FBITS - xe;
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}
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/* Note: At this point upper 32 bits of xm are guaranteed
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to be zero */
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odd = (xm & 0x1) != 0x0;
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switch (ieee754_csr.rm) {
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case FPU_CSR_RN:
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if (round && (sticky || odd))
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xm++;
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break;
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case FPU_CSR_RZ:
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break;
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case FPU_CSR_RU: /* toward +Infinity */
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if ((round || sticky) && !xs)
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xm++;
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break;
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case FPU_CSR_RD: /* toward -Infinity */
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if ((round || sticky) && xs)
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xm++;
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break;
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}
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/* look for valid corner case 0x80000000 */
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if ((xm >> 31) != 0 && (xs == 0 || xm != 0x80000000)) {
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/* This can happen after rounding */
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ieee754_setcx(IEEE754_INVALID_OPERATION);
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return ieee754si_overflow(xs);
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}
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if (round || sticky)
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ieee754_setcx(IEEE754_INEXACT);
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}
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if (xs)
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return -xm;
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else
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return xm;
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}
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