diff options
Diffstat (limited to 'arch/x86/math-emu/reg_divide.c')
| -rw-r--r-- | arch/x86/math-emu/reg_divide.c | 301 |
1 files changed, 138 insertions, 163 deletions
diff --git a/arch/x86/math-emu/reg_divide.c b/arch/x86/math-emu/reg_divide.c index 5cee7ff920d..6827012db34 100644 --- a/arch/x86/math-emu/reg_divide.c +++ b/arch/x86/math-emu/reg_divide.c @@ -26,182 +26,157 @@ */ int FPU_div(int flags, int rm, int control_w) { - FPU_REG x, y; - FPU_REG const *a, *b, *st0_ptr, *st_ptr; - FPU_REG *dest; - u_char taga, tagb, signa, signb, sign, saved_sign; - int tag, deststnr; - - if ( flags & DEST_RM ) - deststnr = rm; - else - deststnr = 0; - - if ( flags & REV ) - { - b = &st(0); - st0_ptr = b; - tagb = FPU_gettag0(); - if ( flags & LOADED ) - { - a = (FPU_REG *)rm; - taga = flags & 0x0f; + FPU_REG x, y; + FPU_REG const *a, *b, *st0_ptr, *st_ptr; + FPU_REG *dest; + u_char taga, tagb, signa, signb, sign, saved_sign; + int tag, deststnr; + + if (flags & DEST_RM) + deststnr = rm; + else + deststnr = 0; + + if (flags & REV) { + b = &st(0); + st0_ptr = b; + tagb = FPU_gettag0(); + if (flags & LOADED) { + a = (FPU_REG *) rm; + taga = flags & 0x0f; + } else { + a = &st(rm); + st_ptr = a; + taga = FPU_gettagi(rm); + } + } else { + a = &st(0); + st0_ptr = a; + taga = FPU_gettag0(); + if (flags & LOADED) { + b = (FPU_REG *) rm; + tagb = flags & 0x0f; + } else { + b = &st(rm); + st_ptr = b; + tagb = FPU_gettagi(rm); + } } - else - { - a = &st(rm); - st_ptr = a; - taga = FPU_gettagi(rm); - } - } - else - { - a = &st(0); - st0_ptr = a; - taga = FPU_gettag0(); - if ( flags & LOADED ) - { - b = (FPU_REG *)rm; - tagb = flags & 0x0f; - } - else - { - b = &st(rm); - st_ptr = b; - tagb = FPU_gettagi(rm); - } - } - signa = getsign(a); - signb = getsign(b); + signa = getsign(a); + signb = getsign(b); - sign = signa ^ signb; + sign = signa ^ signb; - dest = &st(deststnr); - saved_sign = getsign(dest); + dest = &st(deststnr); + saved_sign = getsign(dest); - if ( !(taga | tagb) ) - { - /* Both regs Valid, this should be the most common case. */ - reg_copy(a, &x); - reg_copy(b, &y); - setpositive(&x); - setpositive(&y); - tag = FPU_u_div(&x, &y, dest, control_w, sign); + if (!(taga | tagb)) { + /* Both regs Valid, this should be the most common case. */ + reg_copy(a, &x); + reg_copy(b, &y); + setpositive(&x); + setpositive(&y); + tag = FPU_u_div(&x, &y, dest, control_w, sign); - if ( tag < 0 ) - return tag; + if (tag < 0) + return tag; - FPU_settagi(deststnr, tag); - return tag; - } + FPU_settagi(deststnr, tag); + return tag; + } - if ( taga == TAG_Special ) - taga = FPU_Special(a); - if ( tagb == TAG_Special ) - tagb = FPU_Special(b); + if (taga == TAG_Special) + taga = FPU_Special(a); + if (tagb == TAG_Special) + tagb = FPU_Special(b); - if ( ((taga == TAG_Valid) && (tagb == TW_Denormal)) + if (((taga == TAG_Valid) && (tagb == TW_Denormal)) || ((taga == TW_Denormal) && (tagb == TAG_Valid)) - || ((taga == TW_Denormal) && (tagb == TW_Denormal)) ) - { - if ( denormal_operand() < 0 ) - return FPU_Exception; - - FPU_to_exp16(a, &x); - FPU_to_exp16(b, &y); - tag = FPU_u_div(&x, &y, dest, control_w, sign); - if ( tag < 0 ) - return tag; - - FPU_settagi(deststnr, tag); - return tag; - } - else if ( (taga <= TW_Denormal) && (tagb <= TW_Denormal) ) - { - if ( tagb != TAG_Zero ) - { - /* Want to find Zero/Valid */ - if ( tagb == TW_Denormal ) - { - if ( denormal_operand() < 0 ) - return FPU_Exception; - } - - /* The result is zero. */ - FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr); - setsign(dest, sign); - return TAG_Zero; + || ((taga == TW_Denormal) && (tagb == TW_Denormal))) { + if (denormal_operand() < 0) + return FPU_Exception; + + FPU_to_exp16(a, &x); + FPU_to_exp16(b, &y); + tag = FPU_u_div(&x, &y, dest, control_w, sign); + if (tag < 0) + return tag; + + FPU_settagi(deststnr, tag); + return tag; + } else if ((taga <= TW_Denormal) && (tagb <= TW_Denormal)) { + if (tagb != TAG_Zero) { + /* Want to find Zero/Valid */ + if (tagb == TW_Denormal) { + if (denormal_operand() < 0) + return FPU_Exception; + } + + /* The result is zero. */ + FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr); + setsign(dest, sign); + return TAG_Zero; + } + /* We have an exception condition, either 0/0 or Valid/Zero. */ + if (taga == TAG_Zero) { + /* 0/0 */ + return arith_invalid(deststnr); + } + /* Valid/Zero */ + return FPU_divide_by_zero(deststnr, sign); } - /* We have an exception condition, either 0/0 or Valid/Zero. */ - if ( taga == TAG_Zero ) - { - /* 0/0 */ - return arith_invalid(deststnr); + /* Must have infinities, NaNs, etc */ + else if ((taga == TW_NaN) || (tagb == TW_NaN)) { + if (flags & LOADED) + return real_2op_NaN((FPU_REG *) rm, flags & 0x0f, 0, + st0_ptr); + + if (flags & DEST_RM) { + int tag; + tag = FPU_gettag0(); + if (tag == TAG_Special) + tag = FPU_Special(st0_ptr); + return real_2op_NaN(st0_ptr, tag, rm, + (flags & REV) ? st0_ptr : &st(rm)); + } else { + int tag; + tag = FPU_gettagi(rm); + if (tag == TAG_Special) + tag = FPU_Special(&st(rm)); + return real_2op_NaN(&st(rm), tag, 0, + (flags & REV) ? st0_ptr : &st(rm)); + } + } else if (taga == TW_Infinity) { + if (tagb == TW_Infinity) { + /* infinity/infinity */ + return arith_invalid(deststnr); + } else { + /* tagb must be Valid or Zero */ + if ((tagb == TW_Denormal) && (denormal_operand() < 0)) + return FPU_Exception; + + /* Infinity divided by Zero or Valid does + not raise and exception, but returns Infinity */ + FPU_copy_to_regi(a, TAG_Special, deststnr); + setsign(dest, sign); + return taga; + } + } else if (tagb == TW_Infinity) { + if ((taga == TW_Denormal) && (denormal_operand() < 0)) + return FPU_Exception; + + /* The result is zero. */ + FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr); + setsign(dest, sign); + return TAG_Zero; } - /* Valid/Zero */ - return FPU_divide_by_zero(deststnr, sign); - } - /* Must have infinities, NaNs, etc */ - else if ( (taga == TW_NaN) || (tagb == TW_NaN) ) - { - if ( flags & LOADED ) - return real_2op_NaN((FPU_REG *)rm, flags & 0x0f, 0, st0_ptr); - - if ( flags & DEST_RM ) - { - int tag; - tag = FPU_gettag0(); - if ( tag == TAG_Special ) - tag = FPU_Special(st0_ptr); - return real_2op_NaN(st0_ptr, tag, rm, (flags & REV) ? st0_ptr : &st(rm)); - } - else - { - int tag; - tag = FPU_gettagi(rm); - if ( tag == TAG_Special ) - tag = FPU_Special(&st(rm)); - return real_2op_NaN(&st(rm), tag, 0, (flags & REV) ? st0_ptr : &st(rm)); - } - } - else if (taga == TW_Infinity) - { - if (tagb == TW_Infinity) - { - /* infinity/infinity */ - return arith_invalid(deststnr); - } - else - { - /* tagb must be Valid or Zero */ - if ( (tagb == TW_Denormal) && (denormal_operand() < 0) ) - return FPU_Exception; - - /* Infinity divided by Zero or Valid does - not raise and exception, but returns Infinity */ - FPU_copy_to_regi(a, TAG_Special, deststnr); - setsign(dest, sign); - return taga; - } - } - else if (tagb == TW_Infinity) - { - if ( (taga == TW_Denormal) && (denormal_operand() < 0) ) - return FPU_Exception; - - /* The result is zero. */ - FPU_copy_to_regi(&CONST_Z, TAG_Zero, deststnr); - setsign(dest, sign); - return TAG_Zero; - } #ifdef PARANOID - else - { - EXCEPTION(EX_INTERNAL|0x102); - return FPU_Exception; - } -#endif /* PARANOID */ + else { + EXCEPTION(EX_INTERNAL | 0x102); + return FPU_Exception; + } +#endif /* PARANOID */ return 0; } |