diff options
Diffstat (limited to 'drivers/FPU-emu/reg_add_sub.c')
| -rw-r--r-- | drivers/FPU-emu/reg_add_sub.c | 318 |
1 files changed, 0 insertions, 318 deletions
diff --git a/drivers/FPU-emu/reg_add_sub.c b/drivers/FPU-emu/reg_add_sub.c deleted file mode 100644 index d70889b40..000000000 --- a/drivers/FPU-emu/reg_add_sub.c +++ /dev/null @@ -1,318 +0,0 @@ -/*---------------------------------------------------------------------------+ - | reg_add_sub.c | - | | - | Functions to add or subtract two registers and put the result in a third. | - | | - | Copyright (C) 1992,1993 | - | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | - | Australia. E-mail billm@vaxc.cc.monash.edu.au | - | | - | | - +---------------------------------------------------------------------------*/ - -/*---------------------------------------------------------------------------+ - | For each function, the destination may be any FPU_REG, including one of | - | the source FPU_REGs. | - +---------------------------------------------------------------------------*/ - -#include "exception.h" -#include "reg_constant.h" -#include "fpu_emu.h" -#include "control_w.h" -#include "fpu_system.h" - - -int reg_add(FPU_REG const *a, FPU_REG const *b, FPU_REG *dest, int control_w) -{ - char saved_sign = dest->sign; - int diff; - - if ( !(a->tag | b->tag) ) - { - /* Both registers are valid */ - if (!(a->sign ^ b->sign)) - { - /* signs are the same */ - dest->sign = a->sign; - if ( reg_u_add(a, b, dest, control_w) ) - { - dest->sign = saved_sign; - return 1; - } - return 0; - } - - /* The signs are different, so do a subtraction */ - diff = a->exp - b->exp; - if (!diff) - { - diff = a->sigh - b->sigh; /* Works only if ms bits are identical */ - if (!diff) - { - diff = a->sigl > b->sigl; - if (!diff) - diff = -(a->sigl < b->sigl); - } - } - - if (diff > 0) - { - dest->sign = a->sign; - if ( reg_u_sub(a, b, dest, control_w) ) - { - dest->sign = saved_sign; - return 1; - } - } - else if ( diff == 0 ) - { -#ifdef DENORM_OPERAND - if ( (b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(&CONST_Z, dest); - /* sign depends upon rounding mode */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } - else - { - dest->sign = b->sign; - if ( reg_u_sub(b, a, dest, control_w) ) - { - dest->sign = saved_sign; - return 1; - } - } - return 0; - } - else - { - if ( (a->tag == TW_NaN) || (b->tag == TW_NaN) ) - { return real_2op_NaN(a, b, dest); } - else if (a->tag == TW_Zero) - { - if (b->tag == TW_Zero) - { - char different_signs = a->sign ^ b->sign; - /* Both are zero, result will be zero. */ - reg_move(a, dest); - if (different_signs) - { - /* Signs are different. */ - /* Sign of answer depends upon rounding mode. */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } - } - else - { -#ifdef DENORM_OPERAND - if ( (b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(b, dest); - } - return 0; - } - else if (b->tag == TW_Zero) - { -#ifdef DENORM_OPERAND - if ( (a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(a, dest); return 0; - } - else if (a->tag == TW_Infinity) - { - if (b->tag != TW_Infinity) - { -#ifdef DENORM_OPERAND - if ( (b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(a, dest); return 0; - } - if (a->sign == b->sign) - { - /* They are both + or - infinity */ - reg_move(a, dest); return 0; - } - return arith_invalid(dest); /* Infinity-Infinity is undefined. */ - } - else if (b->tag == TW_Infinity) - { -#ifdef DENORM_OPERAND - if ( (a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(b, dest); return 0; - } - } -#ifdef PARANOID - EXCEPTION(EX_INTERNAL|0x101); -#endif - return 1; -} - - -/* Subtract b from a. (a-b) -> dest */ -int reg_sub(FPU_REG const *a, FPU_REG const *b, FPU_REG *dest, int control_w) -{ - char saved_sign = dest->sign; - int diff; - - if ( !(a->tag | b->tag) ) - { - /* Both registers are valid */ - diff = a->exp - b->exp; - if (!diff) - { - diff = a->sigh - b->sigh; /* Works only if ms bits are identical */ - if (!diff) - { - diff = a->sigl > b->sigl; - if (!diff) - diff = -(a->sigl < b->sigl); - } - } - - switch (a->sign*2 + b->sign) - { - case 0: /* P - P */ - case 3: /* N - N */ - if (diff > 0) - { - /* |a| > |b| */ - dest->sign = a->sign; - if ( reg_u_sub(a, b, dest, control_w) ) - { - dest->sign = saved_sign; - return 1; - } - return 0; - } - else if ( diff == 0 ) - { -#ifdef DENORM_OPERAND - if ( (b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(&CONST_Z, dest); - /* sign depends upon rounding mode */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } - else - { - dest->sign = a->sign ^ SIGN_POS^SIGN_NEG; - if ( reg_u_sub(b, a, dest, control_w) ) - { - dest->sign = saved_sign; - return 1; - } - } - break; - case 1: /* P - N */ - dest->sign = SIGN_POS; - if ( reg_u_add(a, b, dest, control_w) ) - { - dest->sign = saved_sign; - return 1; - } - break; - case 2: /* N - P */ - dest->sign = SIGN_NEG; - if ( reg_u_add(a, b, dest, control_w) ) - { - dest->sign = saved_sign; - return 1; - } - break; - } - return 0; - } - else - { - if ( (a->tag == TW_NaN) || (b->tag == TW_NaN) ) - { return real_2op_NaN(b, a, dest); } - else if (b->tag == TW_Zero) - { - if (a->tag == TW_Zero) - { - char same_signs = !(a->sign ^ b->sign); - /* Both are zero, result will be zero. */ - reg_move(a, dest); /* Answer for different signs. */ - if (same_signs) - { - /* Sign depends upon rounding mode */ - dest->sign = ((control_w & CW_RC) != RC_DOWN) - ? SIGN_POS : SIGN_NEG; - } - } - else - { -#ifdef DENORM_OPERAND - if ( (a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(a, dest); - } - return 0; - } - else if (a->tag == TW_Zero) - { -#ifdef DENORM_OPERAND - if ( (b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(b, dest); - dest->sign ^= SIGN_POS^SIGN_NEG; - return 0; - } - else if (a->tag == TW_Infinity) - { - if (b->tag != TW_Infinity) - { -#ifdef DENORM_OPERAND - if ( (b->tag == TW_Valid) && (b->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(a, dest); return 0; - } - /* Both args are Infinity */ - if (a->sign == b->sign) - { - /* Infinity-Infinity is undefined. */ - return arith_invalid(dest); - } - reg_move(a, dest); - return 0; - } - else if (b->tag == TW_Infinity) - { -#ifdef DENORM_OPERAND - if ( (a->tag == TW_Valid) && (a->exp <= EXP_UNDER) && - denormal_operand() ) - return 1; -#endif DENORM_OPERAND - reg_move(b, dest); - dest->sign ^= SIGN_POS^SIGN_NEG; - return 0; - } - } -#ifdef PARANOID - EXCEPTION(EX_INTERNAL|0x110); -#endif - return 1; -} - |