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extractedLnx/linux-2.6.9/arch/parisc/math-emu/fpudispatch.c_decode_0e.c

static u_int
decode_0e(ir,class,subop,fpregs)
u_int ir,class,subop;
u_int fpregs[];
{
	u_int r1,r2,t;		/* operand register offsets */
	u_int fmt;		/* also sf for class 1 conversions */
	u_int df;		/* dest format for class 1 conversions */
	u_int *status;
	u_int retval, local_status;
	u_int fpu_type_flags;

	status = &fpregs[0];
	local_status = fpregs[0];
	r1 = ((extru(ir,fpr1pos,5)<<1)|(extru(ir,fpxr1pos,1)));
	if (r1 == 0)
		r1 = fpzeroreg;
	t = ((extru(ir,fptpos,5)<<1)|(extru(ir,fpxtpos,1)));
	if (t == 0 && class != 2)
		return(MAJOR_0E_EXCP);
	if (class < 2)		/* class 0 or 1 has 2 bit fmt */
		fmt = extru(ir,fpfmtpos,2);
	else 			/* class 2 and 3 have 1 bit fmt */
		fmt = extru(ir,fp0efmtpos,1);
	/*
	 * An undefined combination, double precision accessing the
	 * right half of a FPR, can get us into trouble.  
	 * Let's just force proper alignment on it.
	 */
	if (fmt == DBL) {
		r1 &= ~1;
		if (class != 1)
			t &= ~1;
	}

	switch (class) {
	    case 0:
		switch (subop) {
			case 0: /* unimplemented */
			case 1:
				return(MAJOR_0E_EXCP);
			case 2: /* FCPY */
				switch (fmt) {
				    case 2:
				    case 3:
					return(MAJOR_0E_EXCP);
				    case 1: /* double */
					fpregs[t+1] = fpregs[r1+1];
				    case 0: /* single */
					fpregs[t] = fpregs[r1];
					return(NOEXCEPTION);
				}
			case 3: /* FABS */
				switch (fmt) {
				    case 2:
				    case 3:
					return(MAJOR_0E_EXCP);
				    case 1: /* double */
					fpregs[t+1] = fpregs[r1+1];
				    case 0: /* single */
					fpregs[t] = fpregs[r1] & 0x7fffffff;
					return(NOEXCEPTION);
				}
			case 6: /* FNEG */
				switch (fmt) {
				    case 2:
				    case 3:
					return(MAJOR_0E_EXCP);
				    case 1: /* double */
					fpregs[t+1] = fpregs[r1+1];
				    case 0: /* single */
					fpregs[t] = fpregs[r1] ^ 0x80000000;
					return(NOEXCEPTION);
				}
			case 7: /* FNEGABS */
				switch (fmt) {
				    case 2:
				    case 3:
					return(MAJOR_0E_EXCP);
				    case 1: /* double */
					fpregs[t+1] = fpregs[r1+1];
				    case 0: /* single */
					fpregs[t] = fpregs[r1] | 0x80000000;
					return(NOEXCEPTION);
				}
			case 4: /* FSQRT */
				switch (fmt) {
				    case 0:
					return(sgl_fsqrt(&fpregs[r1],0,
						&fpregs[t], status));
				    case 1:
					return(dbl_fsqrt(&fpregs[r1],0,
						&fpregs[t], status));
				    case 2:
				    case 3:
					return(MAJOR_0E_EXCP);
				}
			case 5: /* FRMD */
				switch (fmt) {
				    case 0:
					return(sgl_frnd(&fpregs[r1],0,
						&fpregs[t], status));
				    case 1:
					return(dbl_frnd(&fpregs[r1],0,
						&fpregs[t], status));
				    case 2:
				    case 3:
					return(MAJOR_0E_EXCP);
				}
		} /* end of switch (subop */
	
	case 1: /* class 1 */
		df = extru(ir,fpdfpos,2); /* get dest format */
		/*
		 * Fix Crashme problem (writing to 31R in double precision)
		 * here too.
		 */
		if (df == DBL) {
			t &= ~1;
		}
		if ((df & 2) || (fmt & 2))
			return(MAJOR_0E_EXCP);
		
		fmt = (fmt << 1) | df;
		switch (subop) {
			case 0: /* FCNVFF */
				switch(fmt) {
				    case 0: /* sgl/sgl */
					return(MAJOR_0E_EXCP);
				    case 1: /* sgl/dbl */
					return(sgl_to_dbl_fcnvff(&fpregs[r1],0,
						&fpregs[t],status));
				    case 2: /* dbl/sgl */
					return(dbl_to_sgl_fcnvff(&fpregs[r1],0,
						&fpregs[t],status));
				    case 3: /* dbl/dbl */
					return(MAJOR_0E_EXCP);
				}
			case 1: /* FCNVXF */
				switch(fmt) {
				    case 0: /* sgl/sgl */
					return(sgl_to_sgl_fcnvxf(&fpregs[r1],0,
						&fpregs[t],status));
				    case 1: /* sgl/dbl */
					return(sgl_to_dbl_fcnvxf(&fpregs[r1],0,
						&fpregs[t],status));
				    case 2: /* dbl/sgl */
					return(dbl_to_sgl_fcnvxf(&fpregs[r1],0,
						&fpregs[t],status));
				    case 3: /* dbl/dbl */
					return(dbl_to_dbl_fcnvxf(&fpregs[r1],0,
						&fpregs[t],status));
				}
			case 2: /* FCNVFX */
				switch(fmt) {
				    case 0: /* sgl/sgl */
					return(sgl_to_sgl_fcnvfx(&fpregs[r1],0,
						&fpregs[t],status));
				    case 1: /* sgl/dbl */
					return(sgl_to_dbl_fcnvfx(&fpregs[r1],0,
						&fpregs[t],status));
				    case 2: /* dbl/sgl */
					return(dbl_to_sgl_fcnvfx(&fpregs[r1],0,
						&fpregs[t],status));
				    case 3: /* dbl/dbl */
					return(dbl_to_dbl_fcnvfx(&fpregs[r1],0,
						&fpregs[t],status));
				}
			case 3: /* FCNVFXT */
				switch(fmt) {
				    case 0: /* sgl/sgl */
					return(sgl_to_sgl_fcnvfxt(&fpregs[r1],0,
						&fpregs[t],status));
				    case 1: /* sgl/dbl */
					return(sgl_to_dbl_fcnvfxt(&fpregs[r1],0,
						&fpregs[t],status));
				    case 2: /* dbl/sgl */
					return(dbl_to_sgl_fcnvfxt(&fpregs[r1],0,
						&fpregs[t],status));
				    case 3: /* dbl/dbl */
					return(dbl_to_dbl_fcnvfxt(&fpregs[r1],0,
						&fpregs[t],status));
				}
			case 5: /* FCNVUF (PA2.0 only) */
				switch(fmt) {
				    case 0: /* sgl/sgl */
					return(sgl_to_sgl_fcnvuf(&fpregs[r1],0,
						&fpregs[t],status));
				    case 1: /* sgl/dbl */
					return(sgl_to_dbl_fcnvuf(&fpregs[r1],0,
						&fpregs[t],status));
				    case 2: /* dbl/sgl */
					return(dbl_to_sgl_fcnvuf(&fpregs[r1],0,
						&fpregs[t],status));
				    case 3: /* dbl/dbl */
					return(dbl_to_dbl_fcnvuf(&fpregs[r1],0,
						&fpregs[t],status));
				}
			case 6: /* FCNVFU (PA2.0 only) */
				switch(fmt) {
				    case 0: /* sgl/sgl */
					return(sgl_to_sgl_fcnvfu(&fpregs[r1],0,
						&fpregs[t],status));
				    case 1: /* sgl/dbl */
					return(sgl_to_dbl_fcnvfu(&fpregs[r1],0,
						&fpregs[t],status));
				    case 2: /* dbl/sgl */
					return(dbl_to_sgl_fcnvfu(&fpregs[r1],0,
						&fpregs[t],status));
				    case 3: /* dbl/dbl */
					return(dbl_to_dbl_fcnvfu(&fpregs[r1],0,
						&fpregs[t],status));
				}
			case 7: /* FCNVFUT (PA2.0 only) */
				switch(fmt) {
				    case 0: /* sgl/sgl */
					return(sgl_to_sgl_fcnvfut(&fpregs[r1],0,
						&fpregs[t],status));
				    case 1: /* sgl/dbl */
					return(sgl_to_dbl_fcnvfut(&fpregs[r1],0,
						&fpregs[t],status));
				    case 2: /* dbl/sgl */
					return(dbl_to_sgl_fcnvfut(&fpregs[r1],0,
						&fpregs[t],status));
				    case 3: /* dbl/dbl */
					return(dbl_to_dbl_fcnvfut(&fpregs[r1],0,
						&fpregs[t],status));
				}
			case 4: /* undefined */
				return(MAJOR_0C_EXCP);
		} /* end of switch subop */
	case 2: /* class 2 */
		/*
		 * Be careful out there.
		 * Crashme can generate cases where FR31R is specified
		 * as the source or target of a double precision operation.
		 * Since we just pass the address of the floating-point
		 * register to the emulation routines, this can cause
		 * corruption of fpzeroreg.
		 */
		if (fmt == DBL)
			r2 = (extru(ir,fpr2pos,5)<<1);
		else
			r2 = ((extru(ir,fpr2pos,5)<<1)|(extru(ir,fpxr2pos,1)));
		fpu_type_flags=fpregs[FPU_TYPE_FLAG_POS];
		if (r2 == 0)
			r2 = fpzeroreg;
		if  (fpu_type_flags & PA2_0_FPU_FLAG) {
			/* FTEST if nullify bit set, otherwise FCMP */
			if (extru(ir, fpnulpos, 1)) {  /* FTEST */
				/* not legal */
				return(MAJOR_0E_EXCP);
			} else {  /* FCMP */
			switch (fmt) {
				    /*
				     * fmt is only 1 bit long
				     */
				    case 0:
					retval = sgl_fcmp(&fpregs[r1],
						&fpregs[r2],extru(ir,fptpos,5),
						&local_status);
					update_status_cbit(status,local_status,
						fpu_type_flags, subop);
					return(retval);
				    case 1:
					retval = dbl_fcmp(&fpregs[r1],
						&fpregs[r2],extru(ir,fptpos,5),
						&local_status);
					update_status_cbit(status,local_status,
						fpu_type_flags, subop);
					return(retval);
				}
			}
		}  /* end of if for PA2.0 */
		else {  /* PA1.0 & PA1.1 */
		    switch (subop) {
			case 1:
			case 2:
			case 3:
			case 4:
			case 5:
			case 6:
			case 7:
				return(MAJOR_0E_EXCP);
			case 0: /* FCMP */
				switch (fmt) {
				    /*
				     * fmt is only 1 bit long
				     */
				    case 0:
					retval = sgl_fcmp(&fpregs[r1],
						&fpregs[r2],extru(ir,fptpos,5),
						&local_status);
					update_status_cbit(status,local_status,
						fpu_type_flags, subop);
					return(retval);
				    case 1:
					retval = dbl_fcmp(&fpregs[r1],
						&fpregs[r2],extru(ir,fptpos,5),
						&local_status);
					update_status_cbit(status,local_status,
						fpu_type_flags, subop);
					return(retval);
				}
		    } /* end of switch subop */
		} /* end of else for PA1.0 & PA1.1 */
	case 3: /* class 3 */
		/*
		 * Be careful out there.
		 * Crashme can generate cases where FR31R is specified
		 * as the source or target of a double precision operation.
		 * Since we just pass the address of the floating-point
		 * register to the emulation routines, this can cause
		 * corruption of fpzeroreg.
		 */
		if (fmt == DBL)
			r2 = (extru(ir,fpr2pos,5)<<1);
		else
			r2 = ((extru(ir,fpr2pos,5)<<1)|(extru(ir,fpxr2pos,1)));
		if (r2 == 0)
			r2 = fpzeroreg;
		switch (subop) {
			case 5:
			case 6:
			case 7:
				return(MAJOR_0E_EXCP);
			
			/*
			 * Note that fmt is only 1 bit for class 3 */
			case 0: /* FADD */
				switch (fmt) {
				    case 0:
					return(sgl_fadd(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				    case 1:
					return(dbl_fadd(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				}
			case 1: /* FSUB */
				switch (fmt) {
				    case 0:
					return(sgl_fsub(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				    case 1:
					return(dbl_fsub(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				}
			case 2: /* FMPY or XMPYU */
				/*
				 * check for integer multiply (x bit set)
				 */
				if (extru(ir,fpxpos,1)) {
				    /*
				     * emulate XMPYU
				     */
				    switch (fmt) {
					case 0:
					    /*
					     * bad instruction if t specifies
					     * the right half of a register
					     */
					    if (t & 1)
						return(MAJOR_0E_EXCP);
					    BUG();
					    /* unsupported
					     * impyu(&fpregs[r1],&fpregs[r2],
						 * &fpregs[t]);
					     */
					    return(NOEXCEPTION);
					case 1:
						return(MAJOR_0E_EXCP);
				    }
				}
				else { /* FMPY */
				    switch (fmt) {
				        case 0:
					    return(sgl_fmpy(&fpregs[r1],
					       &fpregs[r2],&fpregs[t],status));
				        case 1:
					    return(dbl_fmpy(&fpregs[r1],
					       &fpregs[r2],&fpregs[t],status));
				    }
				}
			case 3: /* FDIV */
				switch (fmt) {
				    case 0:
					return(sgl_fdiv(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				    case 1:
					return(dbl_fdiv(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				}
			case 4: /* FREM */
				switch (fmt) {
				    case 0:
					return(sgl_frem(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				    case 1:
					return(dbl_frem(&fpregs[r1],&fpregs[r2],
						&fpregs[t],status));
				}
		} /* end of class 3 switch */
	} /* end of switch(class) */

	/* If we get here, something is really wrong! */
	return(MAJOR_0E_EXCP);
}

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