static void fxtract(FPU_REG *st0_ptr, u_char st0_tag) { FPU_REG *st_new_ptr; u_char sign; register FPU_REG *st1_ptr = st0_ptr; if (STACK_OVERFLOW) { FPU_stack_overflow(); return; } clear_C1(); if (st0_tag == TAG_Valid) { long e; push(); sign = getsign(st1_ptr); reg_copy(st1_ptr, st_new_ptr); setexponent16(st_new_ptr, exponent(st_new_ptr)); denormal_arg: e = exponent16(st_new_ptr); convert_l2reg(&e, 1); setexponentpos(st_new_ptr, 0); setsign(st_new_ptr, sign); FPU_settag0(TAG_Valid); return; } else if (st0_tag == TAG_Zero) { sign = getsign(st0_ptr); if (FPU_divide_by_zero(0, SIGN_NEG) < 0) return; push(); FPU_copy_to_reg0(&CONST_Z, TAG_Zero); setsign(st_new_ptr, sign); return; } if (st0_tag == TAG_Special) st0_tag = FPU_Special(st0_ptr); if (st0_tag == TW_Denormal) { if (denormal_operand() < 0) return; push(); sign = getsign(st1_ptr); FPU_to_exp16(st1_ptr, st_new_ptr); goto denormal_arg; } else if (st0_tag == TW_Infinity) { sign = getsign(st0_ptr); setpositive(st0_ptr); push(); FPU_copy_to_reg0(&CONST_INF, TAG_Special); setsign(st_new_ptr, sign); return; } else if (st0_tag == TW_NaN) { if (real_1op_NaN(st0_ptr) < 0) return; push(); FPU_copy_to_reg0(st0_ptr, TAG_Special); return; } else if (st0_tag == TAG_Empty) { if (control_word & EX_Invalid) { FPU_stack_underflow(); push(); FPU_stack_underflow(); } else EXCEPTION(EX_StackUnder); } #ifdef PARANOID else EXCEPTION(EX_INTERNAL | 0x119); #endif }
static void fxtract(void) { FPU_REG *st_new_ptr; register FPU_REG *st1_ptr = FPU_st0_ptr; /* anticipate */ if (STACK_OVERFLOW) { stack_overflow(); return; } if (!(FPU_st0_tag ^ TW_Valid)) { long e; #ifdef DENORM_OPERAND if ((FPU_st0_ptr->exp <= EXP_UNDER) && (denormal_operand())) return; #endif /* DENORM_OPERAND */ push(); reg_move(st1_ptr, FPU_st0_ptr); FPU_st0_ptr->exp = EXP_BIAS; e = st1_ptr->exp - EXP_BIAS; convert_l2reg(&e, st1_ptr); return; } else if (FPU_st0_tag == TW_Zero) { char sign = FPU_st0_ptr->sign; divide_by_zero(SIGN_NEG, FPU_st0_ptr); push(); reg_move(&CONST_Z, FPU_st0_ptr); FPU_st0_ptr->sign = sign; return; } else if (FPU_st0_tag == TW_Infinity) { char sign = FPU_st0_ptr->sign; FPU_st0_ptr->sign = SIGN_POS; push(); reg_move(&CONST_INF, FPU_st0_ptr); FPU_st0_ptr->sign = sign; return; } else if (FPU_st0_tag == TW_NaN) { if (!(FPU_st0_ptr->sigh & 0x40000000)) { /* Signaling ? */ EXCEPTION(EX_Invalid); /* Convert to a QNaN */ FPU_st0_ptr->sigh |= 0x40000000; } push(); reg_move(st1_ptr, FPU_st0_ptr); return; } else if (FPU_st0_tag == TW_Empty) { /* Is this the correct * behaviour? */ if (control_word & EX_Invalid) { stack_underflow(); push(); stack_underflow(); } else EXCEPTION(EX_StackUnder); } #ifdef PARANOID else EXCEPTION(EX_INTERNAL | 0x119); #endif /* PARANOID */ }