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Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that 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 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 441 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190520071858.739733335@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
362 lines
8.4 KiB
C
362 lines
8.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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NetWinder Floating Point Emulator
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(c) Rebel.COM, 1998,1999
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(c) Philip Blundell, 1999, 2001
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Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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*/
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#include "fpa11.h"
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#include "fpopcode.h"
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#include "fpa11.inl"
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#include "fpmodule.h"
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#include "fpmodule.inl"
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#include "softfloat.h"
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unsigned int PerformFLT(const unsigned int opcode);
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unsigned int PerformFIX(const unsigned int opcode);
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static unsigned int PerformComparison(const unsigned int opcode);
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unsigned int EmulateCPRT(const unsigned int opcode)
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{
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if (opcode & 0x800000) {
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/* This is some variant of a comparison (PerformComparison
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will sort out which one). Since most of the other CPRT
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instructions are oddball cases of some sort or other it
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makes sense to pull this out into a fast path. */
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return PerformComparison(opcode);
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}
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/* Hint to GCC that we'd like a jump table rather than a load of CMPs */
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switch ((opcode & 0x700000) >> 20) {
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case FLT_CODE >> 20:
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return PerformFLT(opcode);
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break;
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case FIX_CODE >> 20:
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return PerformFIX(opcode);
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break;
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case WFS_CODE >> 20:
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writeFPSR(readRegister(getRd(opcode)));
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break;
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case RFS_CODE >> 20:
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writeRegister(getRd(opcode), readFPSR());
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break;
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default:
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return 0;
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}
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return 1;
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}
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unsigned int PerformFLT(const unsigned int opcode)
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{
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FPA11 *fpa11 = GET_FPA11();
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struct roundingData roundData;
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roundData.mode = SetRoundingMode(opcode);
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roundData.precision = SetRoundingPrecision(opcode);
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roundData.exception = 0;
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switch (opcode & MASK_ROUNDING_PRECISION) {
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case ROUND_SINGLE:
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{
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fpa11->fType[getFn(opcode)] = typeSingle;
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fpa11->fpreg[getFn(opcode)].fSingle = int32_to_float32(&roundData, readRegister(getRd(opcode)));
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}
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break;
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case ROUND_DOUBLE:
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{
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fpa11->fType[getFn(opcode)] = typeDouble;
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fpa11->fpreg[getFn(opcode)].fDouble = int32_to_float64(readRegister(getRd(opcode)));
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}
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break;
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#ifdef CONFIG_FPE_NWFPE_XP
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case ROUND_EXTENDED:
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{
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fpa11->fType[getFn(opcode)] = typeExtended;
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fpa11->fpreg[getFn(opcode)].fExtended = int32_to_floatx80(readRegister(getRd(opcode)));
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}
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break;
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#endif
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default:
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return 0;
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}
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if (roundData.exception)
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float_raise(roundData.exception);
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return 1;
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}
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unsigned int PerformFIX(const unsigned int opcode)
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{
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FPA11 *fpa11 = GET_FPA11();
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unsigned int Fn = getFm(opcode);
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struct roundingData roundData;
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roundData.mode = SetRoundingMode(opcode);
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roundData.precision = SetRoundingPrecision(opcode);
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roundData.exception = 0;
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switch (fpa11->fType[Fn]) {
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case typeSingle:
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{
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writeRegister(getRd(opcode), float32_to_int32(&roundData, fpa11->fpreg[Fn].fSingle));
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}
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break;
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case typeDouble:
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{
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writeRegister(getRd(opcode), float64_to_int32(&roundData, fpa11->fpreg[Fn].fDouble));
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}
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break;
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#ifdef CONFIG_FPE_NWFPE_XP
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case typeExtended:
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{
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writeRegister(getRd(opcode), floatx80_to_int32(&roundData, fpa11->fpreg[Fn].fExtended));
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}
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break;
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#endif
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default:
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return 0;
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}
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if (roundData.exception)
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float_raise(roundData.exception);
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return 1;
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}
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/* This instruction sets the flags N, Z, C, V in the FPSR. */
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static unsigned int PerformComparison(const unsigned int opcode)
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{
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FPA11 *fpa11 = GET_FPA11();
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unsigned int Fn = getFn(opcode), Fm = getFm(opcode);
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int e_flag = opcode & 0x400000; /* 1 if CxFE */
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int n_flag = opcode & 0x200000; /* 1 if CNxx */
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unsigned int flags = 0;
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#ifdef CONFIG_FPE_NWFPE_XP
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floatx80 rFn, rFm;
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/* Check for unordered condition and convert all operands to 80-bit
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format.
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?? Might be some mileage in avoiding this conversion if possible.
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Eg, if both operands are 32-bit, detect this and do a 32-bit
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comparison (cheaper than an 80-bit one). */
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switch (fpa11->fType[Fn]) {
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case typeSingle:
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//printk("single.\n");
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if (float32_is_nan(fpa11->fpreg[Fn].fSingle))
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goto unordered;
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rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle);
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break;
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case typeDouble:
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//printk("double.\n");
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if (float64_is_nan(fpa11->fpreg[Fn].fDouble))
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goto unordered;
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rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble);
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break;
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case typeExtended:
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//printk("extended.\n");
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if (floatx80_is_nan(fpa11->fpreg[Fn].fExtended))
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goto unordered;
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rFn = fpa11->fpreg[Fn].fExtended;
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break;
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default:
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return 0;
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}
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if (CONSTANT_FM(opcode)) {
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//printk("Fm is a constant: #%d.\n",Fm);
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rFm = getExtendedConstant(Fm);
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if (floatx80_is_nan(rFm))
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goto unordered;
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} else {
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//printk("Fm = r%d which contains a ",Fm);
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switch (fpa11->fType[Fm]) {
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case typeSingle:
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//printk("single.\n");
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if (float32_is_nan(fpa11->fpreg[Fm].fSingle))
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goto unordered;
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rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle);
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break;
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case typeDouble:
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//printk("double.\n");
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if (float64_is_nan(fpa11->fpreg[Fm].fDouble))
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goto unordered;
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rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble);
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break;
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case typeExtended:
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//printk("extended.\n");
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if (floatx80_is_nan(fpa11->fpreg[Fm].fExtended))
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goto unordered;
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rFm = fpa11->fpreg[Fm].fExtended;
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break;
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default:
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return 0;
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}
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}
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if (n_flag)
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rFm.high ^= 0x8000;
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/* test for less than condition */
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if (floatx80_lt(rFn, rFm))
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flags |= CC_NEGATIVE;
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/* test for equal condition */
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if (floatx80_eq(rFn, rFm))
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flags |= CC_ZERO;
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/* test for greater than or equal condition */
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if (floatx80_lt(rFm, rFn))
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flags |= CC_CARRY;
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#else
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if (CONSTANT_FM(opcode)) {
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/* Fm is a constant. Do the comparison in whatever precision
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Fn happens to be stored in. */
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if (fpa11->fType[Fn] == typeSingle) {
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float32 rFm = getSingleConstant(Fm);
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float32 rFn = fpa11->fpreg[Fn].fSingle;
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if (float32_is_nan(rFn))
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goto unordered;
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if (n_flag)
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rFm ^= 0x80000000;
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/* test for less than condition */
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if (float32_lt_nocheck(rFn, rFm))
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flags |= CC_NEGATIVE;
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/* test for equal condition */
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if (float32_eq_nocheck(rFn, rFm))
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flags |= CC_ZERO;
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/* test for greater than or equal condition */
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if (float32_lt_nocheck(rFm, rFn))
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flags |= CC_CARRY;
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} else {
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float64 rFm = getDoubleConstant(Fm);
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float64 rFn = fpa11->fpreg[Fn].fDouble;
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if (float64_is_nan(rFn))
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goto unordered;
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if (n_flag)
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rFm ^= 0x8000000000000000ULL;
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/* test for less than condition */
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if (float64_lt_nocheck(rFn, rFm))
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flags |= CC_NEGATIVE;
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/* test for equal condition */
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if (float64_eq_nocheck(rFn, rFm))
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flags |= CC_ZERO;
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/* test for greater than or equal condition */
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if (float64_lt_nocheck(rFm, rFn))
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flags |= CC_CARRY;
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}
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} else {
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/* Both operands are in registers. */
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if (fpa11->fType[Fn] == typeSingle
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&& fpa11->fType[Fm] == typeSingle) {
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float32 rFm = fpa11->fpreg[Fm].fSingle;
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float32 rFn = fpa11->fpreg[Fn].fSingle;
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if (float32_is_nan(rFn)
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|| float32_is_nan(rFm))
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goto unordered;
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if (n_flag)
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rFm ^= 0x80000000;
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/* test for less than condition */
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if (float32_lt_nocheck(rFn, rFm))
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flags |= CC_NEGATIVE;
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/* test for equal condition */
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if (float32_eq_nocheck(rFn, rFm))
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flags |= CC_ZERO;
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/* test for greater than or equal condition */
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if (float32_lt_nocheck(rFm, rFn))
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flags |= CC_CARRY;
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} else {
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/* Promote 32-bit operand to 64 bits. */
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float64 rFm, rFn;
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rFm = (fpa11->fType[Fm] == typeSingle) ?
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float32_to_float64(fpa11->fpreg[Fm].fSingle)
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: fpa11->fpreg[Fm].fDouble;
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rFn = (fpa11->fType[Fn] == typeSingle) ?
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float32_to_float64(fpa11->fpreg[Fn].fSingle)
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: fpa11->fpreg[Fn].fDouble;
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if (float64_is_nan(rFn)
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|| float64_is_nan(rFm))
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goto unordered;
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if (n_flag)
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rFm ^= 0x8000000000000000ULL;
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/* test for less than condition */
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if (float64_lt_nocheck(rFn, rFm))
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flags |= CC_NEGATIVE;
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/* test for equal condition */
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if (float64_eq_nocheck(rFn, rFm))
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flags |= CC_ZERO;
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/* test for greater than or equal condition */
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if (float64_lt_nocheck(rFm, rFn))
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flags |= CC_CARRY;
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}
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}
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#endif
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writeConditionCodes(flags);
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return 1;
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unordered:
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/* ?? The FPA data sheet is pretty vague about this, in particular
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about whether the non-E comparisons can ever raise exceptions.
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This implementation is based on a combination of what it says in
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the data sheet, observation of how the Acorn emulator actually
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behaves (and how programs expect it to) and guesswork. */
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flags |= CC_OVERFLOW;
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flags &= ~(CC_ZERO | CC_NEGATIVE);
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if (BIT_AC & readFPSR())
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flags |= CC_CARRY;
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if (e_flag)
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float_raise(float_flag_invalid);
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writeConditionCodes(flags);
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return 1;
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}
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