1 // SPDX-License-Identifier: GPL-2.0
2 /*---------------------------------------------------------------------------+
5  |  The error handling functions for wm-FPU-emu                              |
9  |                  E-mail   billm@jacobi.maths.monash.edu.au                |
12  +---------------------------------------------------------------------------*/
14 /*---------------------------------------------------------------------------+
19  +---------------------------------------------------------------------------*/
27 #include "exception.h"
68 	EXCEPTION(EX_Invalid);
126 		printk("SW: backward compatibility\n");  in FPU_printall()
128 		printk("SW: condition bit 3\n");  in FPU_printall()
130 		printk("SW: condition bit 2\n");  in FPU_printall()
132 		printk("SW: condition bit 1\n");  in FPU_printall()
134 		printk("SW: condition bit 0\n");  in FPU_printall()
136 		printk("SW: exception summary\n");  in FPU_printall()
138 		printk("SW: stack fault\n");  in FPU_printall()
140 		printk("SW: loss of precision\n");  in FPU_printall()
142 		printk("SW: underflow\n");  in FPU_printall()
144 		printk("SW: overflow\n");  in FPU_printall()
146 		printk("SW: divide by zero\n");  in FPU_printall()
148 		printk("SW: denormalized operand\n");  in FPU_printall()
150 		printk("SW: invalid operation\n");  in FPU_printall()
153 …printk(" SW: b=%d st=%d es=%d sf=%d cc=%d%d%d%d ef=%d%d%d%d%d%d\n", partial_status & 0x8000 ? 1 : …  in FPU_printall()
191 			printk("st(%d)  %c .%04lx %04lx %04lx %04lx e%+-6d ", i,  in FPU_printall()
192 			       getsign(r) ? '-' : '+',  in FPU_printall()
193 			       (long)(r->sigh >> 16),  in FPU_printall()
194 			       (long)(r->sigh & 0xFFFF),  in FPU_printall()
195 			       (long)(r->sigl >> 16),  in FPU_printall()
196 			       (long)(r->sigl & 0xFFFF),  in FPU_printall()
197 			       exponent(r) - EXP_BIAS + 1);  in FPU_printall()
313 		int_type = n - EX_INTERNAL;  in FPU_exception()
315 		/* Set lots of exception bits! */  in FPU_exception()
320 		/* Set the corresponding exception bit */  in FPU_exception()
322 		/* Set summary bits iff exception isn't masked */  in FPU_exception()
327 				/* This bit distinguishes over- from underflow for a stack fault,  in FPU_exception()
328 				   and roundup from round-down for precision loss. */  in FPU_exception()
343 			printk("FP Exception: %s!\n", exception_names[i].name);  in FPU_exception()
346 			printk("FPU emulator: Unknown Exception: 0x%04x!\n", n);  in FPU_exception()
359 		 * The 80486 generates an interrupt on the next non-control FPU  in FPU_exception()
373 /* Returns < 0 if the exception is unmasked */
378 	isNaN = (exponent(a) == EXP_OVER) && (a->sigh & 0x80000000);  in real_1op_NaN()
382 	signalling = isNaN && !(a->sigh & 0x40000000);  in real_1op_NaN()
385 		if (!isNaN) {	/* pseudo-NaN, or other unsupported? */  in real_1op_NaN()
390 			EXCEPTION(EX_Invalid);  in real_1op_NaN()
399 		if (!(a->sigh & 0x80000000)) {	/* pseudo-NaN ? */  in real_1op_NaN()
403 		a->sigh |= 0x40000000;  in real_1op_NaN()
406 	EXCEPTION(EX_Invalid);  in real_1op_NaN()
412 /* Returns < 0 if the exception is unmasked */
430 			    && (a->sigh & 0x80000000)))  in real_2op_NaN()
432 		&& !((exponent(b) == EXP_OVER) && (b->sigh & 0x80000000)));  in real_2op_NaN()
438 		EXCEPTION(EX_Invalid);  in real_2op_NaN()
446 			signalling = !(a->sigh & b->sigh & 0x40000000);  in real_2op_NaN()
456 			signalling = !(a->sigh & 0x40000000);  in real_2op_NaN()
463 		signalling = !(b->sigh & 0x40000000);  in real_2op_NaN()
469 		EXCEPTION(EX_INTERNAL | 0x113);  in real_2op_NaN()
478 		if (!(x->sigh & 0x80000000))	/* pseudo-NaN ? */  in real_2op_NaN()
487 		dest->sigh |= 0x40000000;  in real_2op_NaN()
490 	EXCEPTION(EX_Invalid);  in real_2op_NaN()
496 /* Returns < 0 if the exception is unmasked */
500 	EXCEPTION(EX_Invalid);  in arith_invalid()
524 	EXCEPTION(EX_ZeroDiv);  in FPU_divide_by_zero()
538 		EXCEPTION(flags);  in set_precision_flag()
549 		EXCEPTION(EX_Precision | SW_C1);  in set_precision_flag_up()
559 		EXCEPTION(EX_Precision);  in set_precision_flag_down()
568 		EXCEPTION(EX_Denormal);  in denormal_operand()
584 		addexponent(dest, (-3 * (1 << 13)));  in arith_overflow()
587 	EXCEPTION(EX_Overflow);  in arith_overflow()
589 		/* The overflow exception is masked. */  in arith_overflow()
593 		EXCEPTION(EX_Precision | SW_C1);  in arith_overflow()
607 		if (exponent16(dest) <= EXP_UNDER - 63) {  in arith_underflow()
619 	EXCEPTION(EX_Underflow);  in arith_underflow()
621 		/* The underflow exception is masked. */  in arith_underflow()
622 		EXCEPTION(EX_Precision);  in arith_underflow()
635 		top--;  in FPU_stack_overflow()
639 	EXCEPTION(EX_StackOver);  in FPU_stack_overflow()
653 	EXCEPTION(EX_StackUnder);  in FPU_stack_underflow()
667 	EXCEPTION(EX_StackUnder);  in FPU_stack_underflow_i()
682 	EXCEPTION(EX_StackUnder);  in FPU_stack_underflow_pop()