cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

fpa11_cpdo.c (3179B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3    NetWinder Floating Point Emulator
      4    (c) Rebel.COM, 1998,1999
      5    (c) Philip Blundell, 2001
      6
      7    Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
      8
      9*/
     10
     11#include "fpa11.h"
     12#include "fpopcode.h"
     13
     14unsigned int SingleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
     15unsigned int DoubleCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
     16unsigned int ExtendedCPDO(struct roundingData *roundData, const unsigned int opcode, FPREG * rFd);
     17
     18unsigned int EmulateCPDO(const unsigned int opcode)
     19{
     20	FPA11 *fpa11 = GET_FPA11();
     21	FPREG *rFd;
     22	unsigned int nType, nDest, nRc;
     23	struct roundingData roundData;
     24
     25	/* Get the destination size.  If not valid let Linux perform
     26	   an invalid instruction trap. */
     27	nDest = getDestinationSize(opcode);
     28	if (typeNone == nDest)
     29		return 0;
     30
     31	roundData.mode = SetRoundingMode(opcode);
     32	roundData.precision = SetRoundingPrecision(opcode);
     33	roundData.exception = 0;
     34
     35	/* Compare the size of the operands in Fn and Fm.
     36	   Choose the largest size and perform operations in that size,
     37	   in order to make use of all the precision of the operands.
     38	   If Fm is a constant, we just grab a constant of a size
     39	   matching the size of the operand in Fn. */
     40	if (MONADIC_INSTRUCTION(opcode))
     41		nType = nDest;
     42	else
     43		nType = fpa11->fType[getFn(opcode)];
     44
     45	if (!CONSTANT_FM(opcode)) {
     46		register unsigned int Fm = getFm(opcode);
     47		if (nType < fpa11->fType[Fm]) {
     48			nType = fpa11->fType[Fm];
     49		}
     50	}
     51
     52	rFd = &fpa11->fpreg[getFd(opcode)];
     53
     54	switch (nType) {
     55	case typeSingle:
     56		nRc = SingleCPDO(&roundData, opcode, rFd);
     57		break;
     58	case typeDouble:
     59		nRc = DoubleCPDO(&roundData, opcode, rFd);
     60		break;
     61#ifdef CONFIG_FPE_NWFPE_XP
     62	case typeExtended:
     63		nRc = ExtendedCPDO(&roundData, opcode, rFd);
     64		break;
     65#endif
     66	default:
     67		nRc = 0;
     68	}
     69
     70	/* The CPDO functions used to always set the destination type
     71	   to be the same as their working size. */
     72
     73	if (nRc != 0) {
     74		/* If the operation succeeded, check to see if the result in the
     75		   destination register is the correct size.  If not force it
     76		   to be. */
     77
     78		fpa11->fType[getFd(opcode)] = nDest;
     79
     80#ifdef CONFIG_FPE_NWFPE_XP
     81		if (nDest != nType) {
     82			switch (nDest) {
     83			case typeSingle:
     84				{
     85					if (typeDouble == nType)
     86						rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
     87					else
     88						rFd->fSingle = floatx80_to_float32(&roundData, rFd->fExtended);
     89				}
     90				break;
     91
     92			case typeDouble:
     93				{
     94					if (typeSingle == nType)
     95						rFd->fDouble = float32_to_float64(rFd->fSingle);
     96					else
     97						rFd->fDouble = floatx80_to_float64(&roundData, rFd->fExtended);
     98				}
     99				break;
    100
    101			case typeExtended:
    102				{
    103					if (typeSingle == nType)
    104						rFd->fExtended = float32_to_floatx80(rFd->fSingle);
    105					else
    106						rFd->fExtended = float64_to_floatx80(rFd->fDouble);
    107				}
    108				break;
    109			}
    110		}
    111#else
    112		if (nDest != nType) {
    113			if (nDest == typeSingle)
    114				rFd->fSingle = float64_to_float32(&roundData, rFd->fDouble);
    115			else
    116				rFd->fDouble = float32_to_float64(rFd->fSingle);
    117		}
    118#endif
    119	}
    120
    121	if (roundData.exception)
    122		float_raise(roundData.exception);
    123
    124	return nRc;
    125}