| /*---------------------------------------------------------------------------+ |
| | errors.c | |
| | | |
| | The error handling functions for wm-FPU-emu | |
| | | |
| | Copyright (C) 1992,1993 | |
| | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | |
| | Australia. E-mail apm233m@vaxc.cc.monash.edu.au | |
| | | |
| | | |
| +---------------------------------------------------------------------------*/ |
| |
| /*---------------------------------------------------------------------------+ |
| | Note: | |
| | The file contains code which accesses user memory. | |
| | Emulator static data may change when user memory is accessed, due to | |
| | other processes using the emulator while swapping is in progress. | |
| +---------------------------------------------------------------------------*/ |
| |
| #include <linux/signal.h> |
| |
| #include <asm/segment.h> |
| |
| #include "fpu_system.h" |
| #include "exception.h" |
| #include "fpu_emu.h" |
| #include "status_w.h" |
| #include "control_w.h" |
| #include "reg_constant.h" |
| #include "version.h" |
| |
| /* */ |
| #undef PRINT_MESSAGES |
| /* */ |
| |
| |
| void Un_impl(void) |
| { |
| unsigned char byte1, FPU_modrm; |
| |
| RE_ENTRANT_CHECK_OFF |
| byte1 = get_fs_byte((unsigned char *) FPU_ORIG_EIP); |
| FPU_modrm = get_fs_byte(1 + (unsigned char *) FPU_ORIG_EIP); |
| |
| printk("Unimplemented FPU Opcode at eip=%p : %02x ", |
| FPU_ORIG_EIP, byte1); |
| |
| if (FPU_modrm >= 0300) |
| printk("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7); |
| else |
| printk("/%d\n", (FPU_modrm >> 3) & 7); |
| RE_ENTRANT_CHECK_ON |
| |
| EXCEPTION(EX_Invalid); |
| |
| } |
| |
| |
| |
| |
| void emu_printall() |
| { |
| int i; |
| static char *tag_desc[] = { "Valid", "Zero", "ERROR", "ERROR", |
| "DeNorm", "Inf", "NaN", "Empty" }; |
| unsigned char byte1, FPU_modrm; |
| |
| RE_ENTRANT_CHECK_OFF |
| byte1 = get_fs_byte((unsigned char *) FPU_ORIG_EIP); |
| FPU_modrm = get_fs_byte(1 + (unsigned char *) FPU_ORIG_EIP); |
| |
| #ifdef DEBUGGING |
| if ( status_word & SW_Backward ) printk("SW: backward compatibility\n"); |
| if ( status_word & SW_C3 ) printk("SW: condition bit 3\n"); |
| if ( status_word & SW_C2 ) printk("SW: condition bit 2\n"); |
| if ( status_word & SW_C1 ) printk("SW: condition bit 1\n"); |
| if ( status_word & SW_C0 ) printk("SW: condition bit 0\n"); |
| if ( status_word & SW_Summary ) printk("SW: exception summary\n"); |
| if ( status_word & SW_Stack_Fault ) printk("SW: stack fault\n"); |
| if ( status_word & SW_Precision ) printk("SW: loss of precision\n"); |
| if ( status_word & SW_Underflow ) printk("SW: underflow\n"); |
| if ( status_word & SW_Overflow ) printk("SW: overflow\n"); |
| if ( status_word & SW_Zero_Div ) printk("SW: divide by zero\n"); |
| if ( status_word & SW_Denorm_Op ) printk("SW: denormalized operand\n"); |
| if ( status_word & SW_Invalid ) printk("SW: invalid operation\n"); |
| #endif DEBUGGING |
| |
| status_word = status_word & ~SW_Top; |
| status_word |= (top&7) << SW_Top_Shift; |
| |
| printk("At %p: %02x ", FPU_ORIG_EIP, byte1); |
| if (FPU_modrm >= 0300) |
| printk("%02x (%02x+%d)\n", FPU_modrm, FPU_modrm & 0xf8, FPU_modrm & 7); |
| else |
| printk("/%d, mod=%d rm=%d\n", |
| (FPU_modrm >> 3) & 7, (FPU_modrm >> 6) & 3, FPU_modrm & 7); |
| |
| printk(" SW: b=%d st=%d es=%d sf=%d cc=%d%d%d%d ef=%d%d%d%d%d%d\n", |
| status_word & 0x8000 ? 1 : 0, /* busy */ |
| (status_word & 0x3800) >> 11, /* stack top pointer */ |
| status_word & 0x80 ? 1 : 0, /* Error summary status */ |
| status_word & 0x40 ? 1 : 0, /* Stack flag */ |
| status_word & SW_C3?1:0, status_word & SW_C2?1:0, /* cc */ |
| status_word & SW_C1?1:0, status_word & SW_C0?1:0, /* cc */ |
| status_word & SW_Precision?1:0, status_word & SW_Underflow?1:0, |
| status_word & SW_Overflow?1:0, status_word & SW_Zero_Div?1:0, |
| status_word & SW_Denorm_Op?1:0, status_word & SW_Invalid?1:0); |
| |
| printk(" CW: ic=%d rc=%d%d pc=%d%d iem=%d ef=%d%d%d%d%d%d\n", |
| control_word & 0x1000 ? 1 : 0, |
| (control_word & 0x800) >> 11, (control_word & 0x400) >> 10, |
| (control_word & 0x200) >> 9, (control_word & 0x100) >> 8, |
| control_word & 0x80 ? 1 : 0, |
| control_word & SW_Precision?1:0, control_word & SW_Underflow?1:0, |
| control_word & SW_Overflow?1:0, control_word & SW_Zero_Div?1:0, |
| control_word & SW_Denorm_Op?1:0, control_word & SW_Invalid?1:0); |
| |
| for ( i = 0; i < 8; i++ ) |
| { |
| FPU_REG *r = &st(i); |
| switch (r->tag) |
| { |
| case TW_Empty: |
| continue; |
| break; |
| case TW_Zero: |
| printk("st(%d) %c .0000 0000 0000 0000 ", |
| i, r->sign ? '-' : '+'); |
| break; |
| case TW_Valid: |
| case TW_NaN: |
| case TW_Denormal: |
| case TW_Infinity: |
| printk("st(%d) %c .%04x %04x %04x %04x e%+-6d ", i, |
| r->sign ? '-' : '+', |
| (long)(r->sigh >> 16), |
| (long)(r->sigh & 0xFFFF), |
| (long)(r->sigl >> 16), |
| (long)(r->sigl & 0xFFFF), |
| r->exp - EXP_BIAS + 1); |
| break; |
| default: |
| printk("Whoops! Error in errors.c "); |
| break; |
| } |
| printk("%s\n", tag_desc[(int) (unsigned) r->tag]); |
| } |
| |
| printk("[data] %c .%04x %04x %04x %04x e%+-6d ", |
| FPU_loaded_data.sign ? '-' : '+', |
| (long)(FPU_loaded_data.sigh >> 16), |
| (long)(FPU_loaded_data.sigh & 0xFFFF), |
| (long)(FPU_loaded_data.sigl >> 16), |
| (long)(FPU_loaded_data.sigl & 0xFFFF), |
| FPU_loaded_data.exp - EXP_BIAS + 1); |
| printk("%s\n", tag_desc[(int) (unsigned) FPU_loaded_data.tag]); |
| RE_ENTRANT_CHECK_ON |
| |
| } |
| |
| static struct { |
| int type; |
| char *name; |
| } exception_names[] = { |
| { EX_StackOver, "stack overflow" }, |
| { EX_StackUnder, "stack underflow" }, |
| { EX_Precision, "loss of precision" }, |
| { EX_Underflow, "underflow" }, |
| { EX_Overflow, "overflow" }, |
| { EX_ZeroDiv, "divide by zero" }, |
| { EX_Denormal, "denormalized operand" }, |
| { EX_Invalid, "invalid operation" }, |
| { EX_INTERNAL, "INTERNAL BUG in "FPU_VERSION }, |
| { 0, NULL } |
| }; |
| |
| /* |
| EX_INTERNAL is always given with a code which indicates where the |
| error was detected. |
| |
| Internal error types: |
| 0x14 in e14.c |
| 0x1nn in a *.c file: |
| 0x101 in reg_add_sub.c |
| 0x102 in reg_mul.c |
| 0x103 in poly_sin.c |
| 0x104 in poly_tan.c |
| 0x105 in reg_mul.c |
| 0x106 in reg_mov.c |
| 0x107 in fpu_trig.c |
| 0x108 in reg_compare.c |
| 0x109 in reg_compare.c |
| 0x110 in reg_add_sub.c |
| 0x111 in interface.c |
| 0x112 in fpu_trig.c |
| 0x113 in reg_add_sub.c |
| 0x114 in reg_ld_str.c |
| 0x115 in fpu_trig.c |
| 0x116 in fpu_trig.c |
| 0x117 in fpu_trig.c |
| 0x118 in fpu_trig.c |
| 0x119 in fpu_trig.c |
| 0x120 in poly_atan.c |
| 0x121 in reg_compare.c |
| 0x122 in reg_compare.c |
| 0x123 in reg_compare.c |
| 0x2nn in an *.s file: |
| 0x201 in reg_u_add.S |
| 0x202 in reg_u_div.S |
| 0x203 in reg_u_div.S |
| 0x204 in reg_u_div.S |
| 0x205 in reg_u_mul.S |
| 0x206 in reg_u_sub.S |
| 0x207 in wm_sqrt.S |
| 0x208 in reg_div.S |
| 0x209 in reg_u_sub.S |
| 0x210 in reg_u_sub.S |
| 0x211 in reg_u_sub.S |
| 0x212 in reg_u_sub.S |
| 0x213 in wm_sqrt.S |
| 0x214 in wm_sqrt.S |
| 0x215 in wm_sqrt.S |
| 0x216 in reg_round.S |
| 0x217 in reg_round.S |
| 0x218 in reg_round.S |
| */ |
| |
| extern "C" void exception(int n) |
| { |
| int i, int_type; |
| |
| int_type = 0; /* Needed only to stop compiler warnings */ |
| if ( n & EX_INTERNAL ) |
| { |
| int_type = n - EX_INTERNAL; |
| n = EX_INTERNAL; |
| /* Set lots of exception bits! */ |
| status_word |= (SW_Exc_Mask | SW_Summary | FPU_BUSY); |
| } |
| else |
| { |
| /* Extract only the bits which we use to set the status word */ |
| n &= (SW_Exc_Mask); |
| /* Set the corresponding exception bit */ |
| status_word |= n; |
| if ( status_word & ~control_word & CW_Exceptions ) |
| status_word |= SW_Summary; |
| if ( n & (SW_Stack_Fault | EX_Precision) ) |
| { |
| if ( !(n & SW_C1) ) |
| /* This bit distinguishes over- from underflow for a stack fault, |
| and roundup from round-down for precision loss. */ |
| status_word &= ~SW_C1; |
| } |
| } |
| |
| RE_ENTRANT_CHECK_OFF |
| if ( (~control_word & n & CW_Exceptions) || (n == EX_INTERNAL) ) |
| { |
| #ifdef PRINT_MESSAGES |
| /* My message from the sponsor */ |
| printk(FPU_VERSION" "__DATE__" (C) W. Metzenthen.\n"); |
| #endif PRINT_MESSAGES |
| |
| /* Get a name string for error reporting */ |
| for (i=0; exception_names[i].type; i++) |
| if ( (exception_names[i].type & n) == exception_names[i].type ) |
| break; |
| |
| if (exception_names[i].type) |
| { |
| #ifdef PRINT_MESSAGES |
| printk("FP Exception: %s!\n", exception_names[i].name); |
| #endif PRINT_MESSAGES |
| } |
| else |
| printk("FP emulator: Unknown Exception: 0x%04x!\n", n); |
| |
| if ( n == EX_INTERNAL ) |
| { |
| printk("FP emulator: Internal error type 0x%04x\n", int_type); |
| emu_printall(); |
| } |
| #ifdef PRINT_MESSAGES |
| else |
| emu_printall(); |
| #endif PRINT_MESSAGES |
| |
| /* |
| * The 80486 generates an interrupt on the next non-control FPU |
| * instruction. So we need some means of flagging it. |
| * We use the ES (Error Summary) bit for this, assuming that |
| * this is the way a real FPU does it (until I can check it out), |
| * if not, then some method such as the following kludge might |
| * be needed. |
| */ |
| /* regs[0].tag |= TW_FPU_Interrupt; */ |
| } |
| RE_ENTRANT_CHECK_ON |
| |
| #ifdef __DEBUG__ |
| math_abort(FPU_info,SIGFPE); |
| #endif __DEBUG__ |
| |
| } |
| |
| |
| /* Real operation attempted on two operands, one a NaN */ |
| extern "C" void real_2op_NaN(FPU_REG *a, FPU_REG *b, FPU_REG *dest) |
| { |
| FPU_REG *x; |
| int signalling; |
| |
| x = a; |
| if (a->tag == TW_NaN) |
| { |
| if (b->tag == TW_NaN) |
| { |
| signalling = !(a->sigh & b->sigh & 0x40000000); |
| /* find the "larger" */ |
| if ( *(long long *)&(a->sigl) < *(long long *)&(b->sigl) ) |
| x = b; |
| } |
| else |
| { |
| /* return the quiet version of the NaN in a */ |
| signalling = !(a->sigh & 0x40000000); |
| } |
| } |
| else |
| #ifdef PARANOID |
| if (b->tag == TW_NaN) |
| #endif PARANOID |
| { |
| signalling = !(b->sigh & 0x40000000); |
| x = b; |
| } |
| #ifdef PARANOID |
| else |
| { |
| signalling = 0; |
| EXCEPTION(EX_INTERNAL|0x113); |
| x = &CONST_QNaN; |
| } |
| #endif PARANOID |
| |
| if ( !signalling ) |
| { |
| if ( !(x->sigh & 0x80000000) ) /* pseudo-NaN ? */ |
| x = &CONST_QNaN; |
| reg_move(x, dest); |
| return; |
| } |
| |
| if ( control_word & CW_Invalid ) |
| { |
| /* The masked response */ |
| if ( !(x->sigh & 0x80000000) ) /* pseudo-NaN ? */ |
| x = &CONST_QNaN; |
| reg_move(x, dest); |
| /* ensure a Quiet NaN */ |
| dest->sigh |= 0x40000000; |
| } |
| |
| EXCEPTION(EX_Invalid); |
| |
| return; |
| } |
| |
| /* Invalid arith operation on Valid registers */ |
| extern "C" void arith_invalid(FPU_REG *dest) |
| { |
| |
| if ( control_word & CW_Invalid ) |
| { |
| /* The masked response */ |
| reg_move(&CONST_QNaN, dest); |
| } |
| |
| EXCEPTION(EX_Invalid); |
| |
| return; |
| |
| } |
| |
| |
| /* Divide a finite number by zero */ |
| extern "C" void divide_by_zero(int sign, FPU_REG *dest) |
| { |
| |
| if ( control_word & CW_ZeroDiv ) |
| { |
| /* The masked response */ |
| reg_move(&CONST_INF, dest); |
| dest->sign = (unsigned char)sign; |
| } |
| |
| EXCEPTION(EX_ZeroDiv); |
| |
| return; |
| |
| } |
| |
| |
| /* This may be called often, so keep it lean */ |
| extern "C" void set_precision_flag_up(void) |
| { |
| if ( control_word & CW_Precision ) |
| status_word |= (SW_Precision | SW_C1); /* The masked response */ |
| else |
| exception(EX_Precision | SW_C1); |
| |
| } |
| |
| |
| /* This may be called often, so keep it lean */ |
| extern "C" void set_precision_flag_down(void) |
| { |
| if ( control_word & CW_Precision ) |
| { /* The masked response */ |
| status_word &= ~SW_C1; |
| status_word |= SW_Precision; |
| } |
| else |
| exception(EX_Precision); |
| } |
| |
| |
| extern "C" int denormal_operand(void) |
| { |
| if ( control_word & CW_Denormal ) |
| { /* The masked response */ |
| status_word |= SW_Denorm_Op; |
| return 0; |
| } |
| else |
| { |
| exception(EX_Denormal); |
| return 1; |
| } |
| } |
| |
| |
| extern "C" void arith_overflow(FPU_REG *dest) |
| { |
| |
| if ( control_word & CW_Overflow ) |
| { |
| char sign; |
| /* The masked response */ |
| /* **** The response here depends upon the rounding mode */ |
| sign = dest->sign; |
| reg_move(&CONST_INF, dest); |
| dest->sign = sign; |
| } |
| else |
| { |
| /* Subtract the magic number from the exponent */ |
| dest->exp -= (3 * (1 << 13)); |
| } |
| |
| /* By definition, precision is lost. |
| It appears that the roundup bit (C1) is also set by convention. */ |
| EXCEPTION(EX_Overflow | EX_Precision | SW_C1); |
| |
| return; |
| |
| } |
| |
| |
| extern "C" void arith_underflow(FPU_REG *dest) |
| { |
| |
| if ( control_word & CW_Underflow ) |
| { |
| /* The masked response */ |
| if ( dest->exp <= EXP_UNDER - 63 ) |
| reg_move(&CONST_Z, dest); |
| } |
| else |
| { |
| /* Add the magic number to the exponent */ |
| dest->exp += (3 * (1 << 13)); |
| } |
| |
| EXCEPTION(EX_Underflow); |
| |
| return; |
| } |
| |
| |
| void stack_overflow(void) |
| { |
| |
| if ( control_word & CW_Invalid ) |
| { |
| /* The masked response */ |
| top--; |
| reg_move(&CONST_QNaN, FPU_st0_ptr = &st(0)); |
| } |
| |
| EXCEPTION(EX_StackOver); |
| |
| return; |
| |
| } |
| |
| |
| void stack_underflow(void) |
| { |
| |
| if ( control_word & CW_Invalid ) |
| { |
| /* The masked response */ |
| reg_move(&CONST_QNaN, FPU_st0_ptr); |
| } |
| |
| EXCEPTION(EX_StackUnder); |
| |
| return; |
| |
| } |
| |
| |
| void stack_underflow_i(int i) |
| { |
| |
| if ( control_word & CW_Invalid ) |
| { |
| /* The masked response */ |
| reg_move(&CONST_QNaN, &(st(i))); |
| } |
| |
| EXCEPTION(EX_StackUnder); |
| |
| return; |
| |
| } |
| |
| |
| void stack_underflow_pop(int i) |
| { |
| |
| if ( control_word & CW_Invalid ) |
| { |
| /* The masked response */ |
| reg_move(&CONST_QNaN, &(st(i))); |
| pop(); |
| } |
| |
| EXCEPTION(EX_StackUnder); |
| |
| return; |
| |
| } |
| |
