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							- /*
 
-     NetWinder Floating Point Emulator
 
-     (c) Rebel.COM, 1998,1999
 
-     (c) Philip Blundell, 1999, 2001
 
-     Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
 
-     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.
 
- */
 
- #include "fpa11.h"
 
- #include "fpopcode.h"
 
- #include "fpa11.inl"
 
- #include "fpmodule.h"
 
- #include "fpmodule.inl"
 
- #include "softfloat.h"
 
- unsigned int PerformFLT(const unsigned int opcode);
 
- unsigned int PerformFIX(const unsigned int opcode);
 
- static unsigned int PerformComparison(const unsigned int opcode);
 
- unsigned int EmulateCPRT(const unsigned int opcode)
 
- {
 
- 	if (opcode & 0x800000) {
 
- 		/* This is some variant of a comparison (PerformComparison
 
- 		   will sort out which one).  Since most of the other CPRT
 
- 		   instructions are oddball cases of some sort or other it
 
- 		   makes sense to pull this out into a fast path.  */
 
- 		return PerformComparison(opcode);
 
- 	}
 
- 	/* Hint to GCC that we'd like a jump table rather than a load of CMPs */
 
- 	switch ((opcode & 0x700000) >> 20) {
 
- 	case FLT_CODE >> 20:
 
- 		return PerformFLT(opcode);
 
- 		break;
 
- 	case FIX_CODE >> 20:
 
- 		return PerformFIX(opcode);
 
- 		break;
 
- 	case WFS_CODE >> 20:
 
- 		writeFPSR(readRegister(getRd(opcode)));
 
- 		break;
 
- 	case RFS_CODE >> 20:
 
- 		writeRegister(getRd(opcode), readFPSR());
 
- 		break;
 
- 	default:
 
- 		return 0;
 
- 	}
 
- 	return 1;
 
- }
 
- unsigned int PerformFLT(const unsigned int opcode)
 
- {
 
- 	FPA11 *fpa11 = GET_FPA11();
 
- 	struct roundingData roundData;
 
- 	roundData.mode = SetRoundingMode(opcode);
 
- 	roundData.precision = SetRoundingPrecision(opcode);
 
- 	roundData.exception = 0;
 
- 	switch (opcode & MASK_ROUNDING_PRECISION) {
 
- 	case ROUND_SINGLE:
 
- 		{
 
- 			fpa11->fType[getFn(opcode)] = typeSingle;
 
- 			fpa11->fpreg[getFn(opcode)].fSingle = int32_to_float32(&roundData, readRegister(getRd(opcode)));
 
- 		}
 
- 		break;
 
- 	case ROUND_DOUBLE:
 
- 		{
 
- 			fpa11->fType[getFn(opcode)] = typeDouble;
 
- 			fpa11->fpreg[getFn(opcode)].fDouble = int32_to_float64(readRegister(getRd(opcode)));
 
- 		}
 
- 		break;
 
- #ifdef CONFIG_FPE_NWFPE_XP
 
- 	case ROUND_EXTENDED:
 
- 		{
 
- 			fpa11->fType[getFn(opcode)] = typeExtended;
 
- 			fpa11->fpreg[getFn(opcode)].fExtended = int32_to_floatx80(readRegister(getRd(opcode)));
 
- 		}
 
- 		break;
 
- #endif
 
- 	default:
 
- 		return 0;
 
- 	}
 
- 	if (roundData.exception)
 
- 		float_raise(roundData.exception);
 
- 	return 1;
 
- }
 
- unsigned int PerformFIX(const unsigned int opcode)
 
- {
 
- 	FPA11 *fpa11 = GET_FPA11();
 
- 	unsigned int Fn = getFm(opcode);
 
- 	struct roundingData roundData;
 
- 	roundData.mode = SetRoundingMode(opcode);
 
- 	roundData.precision = SetRoundingPrecision(opcode);
 
- 	roundData.exception = 0;
 
- 	switch (fpa11->fType[Fn]) {
 
- 	case typeSingle:
 
- 		{
 
- 			writeRegister(getRd(opcode), float32_to_int32(&roundData, fpa11->fpreg[Fn].fSingle));
 
- 		}
 
- 		break;
 
- 	case typeDouble:
 
- 		{
 
- 			writeRegister(getRd(opcode), float64_to_int32(&roundData, fpa11->fpreg[Fn].fDouble));
 
- 		}
 
- 		break;
 
- #ifdef CONFIG_FPE_NWFPE_XP
 
- 	case typeExtended:
 
- 		{
 
- 			writeRegister(getRd(opcode), floatx80_to_int32(&roundData, fpa11->fpreg[Fn].fExtended));
 
- 		}
 
- 		break;
 
- #endif
 
- 	default:
 
- 		return 0;
 
- 	}
 
- 	if (roundData.exception)
 
- 		float_raise(roundData.exception);
 
- 	return 1;
 
- }
 
- /* This instruction sets the flags N, Z, C, V in the FPSR. */
 
- static unsigned int PerformComparison(const unsigned int opcode)
 
- {
 
- 	FPA11 *fpa11 = GET_FPA11();
 
- 	unsigned int Fn = getFn(opcode), Fm = getFm(opcode);
 
- 	int e_flag = opcode & 0x400000;	/* 1 if CxFE */
 
- 	int n_flag = opcode & 0x200000;	/* 1 if CNxx */
 
- 	unsigned int flags = 0;
 
- #ifdef CONFIG_FPE_NWFPE_XP
 
- 	floatx80 rFn, rFm;
 
- 	/* Check for unordered condition and convert all operands to 80-bit
 
- 	   format.
 
- 	   ?? Might be some mileage in avoiding this conversion if possible.
 
- 	   Eg, if both operands are 32-bit, detect this and do a 32-bit
 
- 	   comparison (cheaper than an 80-bit one).  */
 
- 	switch (fpa11->fType[Fn]) {
 
- 	case typeSingle:
 
- 		//printk("single.\n");
 
- 		if (float32_is_nan(fpa11->fpreg[Fn].fSingle))
 
- 			goto unordered;
 
- 		rFn = float32_to_floatx80(fpa11->fpreg[Fn].fSingle);
 
- 		break;
 
- 	case typeDouble:
 
- 		//printk("double.\n");
 
- 		if (float64_is_nan(fpa11->fpreg[Fn].fDouble))
 
- 			goto unordered;
 
- 		rFn = float64_to_floatx80(fpa11->fpreg[Fn].fDouble);
 
- 		break;
 
- 	case typeExtended:
 
- 		//printk("extended.\n");
 
- 		if (floatx80_is_nan(fpa11->fpreg[Fn].fExtended))
 
- 			goto unordered;
 
- 		rFn = fpa11->fpreg[Fn].fExtended;
 
- 		break;
 
- 	default:
 
- 		return 0;
 
- 	}
 
- 	if (CONSTANT_FM(opcode)) {
 
- 		//printk("Fm is a constant: #%d.\n",Fm);
 
- 		rFm = getExtendedConstant(Fm);
 
- 		if (floatx80_is_nan(rFm))
 
- 			goto unordered;
 
- 	} else {
 
- 		//printk("Fm = r%d which contains a ",Fm);
 
- 		switch (fpa11->fType[Fm]) {
 
- 		case typeSingle:
 
- 			//printk("single.\n");
 
- 			if (float32_is_nan(fpa11->fpreg[Fm].fSingle))
 
- 				goto unordered;
 
- 			rFm = float32_to_floatx80(fpa11->fpreg[Fm].fSingle);
 
- 			break;
 
- 		case typeDouble:
 
- 			//printk("double.\n");
 
- 			if (float64_is_nan(fpa11->fpreg[Fm].fDouble))
 
- 				goto unordered;
 
- 			rFm = float64_to_floatx80(fpa11->fpreg[Fm].fDouble);
 
- 			break;
 
- 		case typeExtended:
 
- 			//printk("extended.\n");
 
- 			if (floatx80_is_nan(fpa11->fpreg[Fm].fExtended))
 
- 				goto unordered;
 
- 			rFm = fpa11->fpreg[Fm].fExtended;
 
- 			break;
 
- 		default:
 
- 			return 0;
 
- 		}
 
- 	}
 
- 	if (n_flag)
 
- 		rFm.high ^= 0x8000;
 
- 	/* test for less than condition */
 
- 	if (floatx80_lt(rFn, rFm))
 
- 		flags |= CC_NEGATIVE;
 
- 	/* test for equal condition */
 
- 	if (floatx80_eq(rFn, rFm))
 
- 		flags |= CC_ZERO;
 
- 	/* test for greater than or equal condition */
 
- 	if (floatx80_lt(rFm, rFn))
 
- 		flags |= CC_CARRY;
 
- #else
 
- 	if (CONSTANT_FM(opcode)) {
 
- 		/* Fm is a constant.  Do the comparison in whatever precision
 
- 		   Fn happens to be stored in.  */
 
- 		if (fpa11->fType[Fn] == typeSingle) {
 
- 			float32 rFm = getSingleConstant(Fm);
 
- 			float32 rFn = fpa11->fpreg[Fn].fSingle;
 
- 			if (float32_is_nan(rFn))
 
- 				goto unordered;
 
- 			if (n_flag)
 
- 				rFm ^= 0x80000000;
 
- 			/* test for less than condition */
 
- 			if (float32_lt_nocheck(rFn, rFm))
 
- 				flags |= CC_NEGATIVE;
 
- 			/* test for equal condition */
 
- 			if (float32_eq_nocheck(rFn, rFm))
 
- 				flags |= CC_ZERO;
 
- 			/* test for greater than or equal condition */
 
- 			if (float32_lt_nocheck(rFm, rFn))
 
- 				flags |= CC_CARRY;
 
- 		} else {
 
- 			float64 rFm = getDoubleConstant(Fm);
 
- 			float64 rFn = fpa11->fpreg[Fn].fDouble;
 
- 			if (float64_is_nan(rFn))
 
- 				goto unordered;
 
- 			if (n_flag)
 
- 				rFm ^= 0x8000000000000000ULL;
 
- 			/* test for less than condition */
 
- 			if (float64_lt_nocheck(rFn, rFm))
 
- 				flags |= CC_NEGATIVE;
 
- 			/* test for equal condition */
 
- 			if (float64_eq_nocheck(rFn, rFm))
 
- 				flags |= CC_ZERO;
 
- 			/* test for greater than or equal condition */
 
- 			if (float64_lt_nocheck(rFm, rFn))
 
- 				flags |= CC_CARRY;
 
- 		}
 
- 	} else {
 
- 		/* Both operands are in registers.  */
 
- 		if (fpa11->fType[Fn] == typeSingle
 
- 		    && fpa11->fType[Fm] == typeSingle) {
 
- 			float32 rFm = fpa11->fpreg[Fm].fSingle;
 
- 			float32 rFn = fpa11->fpreg[Fn].fSingle;
 
- 			if (float32_is_nan(rFn)
 
- 			    || float32_is_nan(rFm))
 
- 				goto unordered;
 
- 			if (n_flag)
 
- 				rFm ^= 0x80000000;
 
- 			/* test for less than condition */
 
- 			if (float32_lt_nocheck(rFn, rFm))
 
- 				flags |= CC_NEGATIVE;
 
- 			/* test for equal condition */
 
- 			if (float32_eq_nocheck(rFn, rFm))
 
- 				flags |= CC_ZERO;
 
- 			/* test for greater than or equal condition */
 
- 			if (float32_lt_nocheck(rFm, rFn))
 
- 				flags |= CC_CARRY;
 
- 		} else {
 
- 			/* Promote 32-bit operand to 64 bits.  */
 
- 			float64 rFm, rFn;
 
- 			rFm = (fpa11->fType[Fm] == typeSingle) ?
 
- 			    float32_to_float64(fpa11->fpreg[Fm].fSingle)
 
- 			    : fpa11->fpreg[Fm].fDouble;
 
- 			rFn = (fpa11->fType[Fn] == typeSingle) ?
 
- 			    float32_to_float64(fpa11->fpreg[Fn].fSingle)
 
- 			    : fpa11->fpreg[Fn].fDouble;
 
- 			if (float64_is_nan(rFn)
 
- 			    || float64_is_nan(rFm))
 
- 				goto unordered;
 
- 			if (n_flag)
 
- 				rFm ^= 0x8000000000000000ULL;
 
- 			/* test for less than condition */
 
- 			if (float64_lt_nocheck(rFn, rFm))
 
- 				flags |= CC_NEGATIVE;
 
- 			/* test for equal condition */
 
- 			if (float64_eq_nocheck(rFn, rFm))
 
- 				flags |= CC_ZERO;
 
- 			/* test for greater than or equal condition */
 
- 			if (float64_lt_nocheck(rFm, rFn))
 
- 				flags |= CC_CARRY;
 
- 		}
 
- 	}
 
- #endif
 
- 	writeConditionCodes(flags);
 
- 	return 1;
 
-       unordered:
 
- 	/* ?? The FPA data sheet is pretty vague about this, in particular
 
- 	   about whether the non-E comparisons can ever raise exceptions.
 
- 	   This implementation is based on a combination of what it says in
 
- 	   the data sheet, observation of how the Acorn emulator actually
 
- 	   behaves (and how programs expect it to) and guesswork.  */
 
- 	flags |= CC_OVERFLOW;
 
- 	flags &= ~(CC_ZERO | CC_NEGATIVE);
 
- 	if (BIT_AC & readFPSR())
 
- 		flags |= CC_CARRY;
 
- 	if (e_flag)
 
- 		float_raise(float_flag_invalid);
 
- 	writeConditionCodes(flags);
 
- 	return 1;
 
- }
 
 
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