![Linus Torvalds](/assets/img/avatar_default.png)
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
128 lines
2.7 KiB
C
128 lines
2.7 KiB
C
/*---------------------------------------------------------------------------+
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| fpu_tags.c |
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| Set FPU register tags. |
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| Copyright (C) 1997 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, Australia |
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| E-mail billm@jacobi.maths.monash.edu.au |
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+---------------------------------------------------------------------------*/
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#include "fpu_emu.h"
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#include "fpu_system.h"
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#include "exception.h"
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void FPU_pop(void)
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{
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fpu_tag_word |= 3 << ((top & 7)*2);
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top++;
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}
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int FPU_gettag0(void)
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{
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return (fpu_tag_word >> ((top & 7)*2)) & 3;
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}
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int FPU_gettagi(int stnr)
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{
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return (fpu_tag_word >> (((top+stnr) & 7)*2)) & 3;
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}
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int FPU_gettag(int regnr)
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{
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return (fpu_tag_word >> ((regnr & 7)*2)) & 3;
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}
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void FPU_settag0(int tag)
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{
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int regnr = top;
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regnr &= 7;
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fpu_tag_word &= ~(3 << (regnr*2));
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fpu_tag_word |= (tag & 3) << (regnr*2);
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}
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void FPU_settagi(int stnr, int tag)
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{
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int regnr = stnr+top;
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regnr &= 7;
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fpu_tag_word &= ~(3 << (regnr*2));
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fpu_tag_word |= (tag & 3) << (regnr*2);
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}
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void FPU_settag(int regnr, int tag)
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{
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regnr &= 7;
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fpu_tag_word &= ~(3 << (regnr*2));
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fpu_tag_word |= (tag & 3) << (regnr*2);
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}
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int FPU_Special(FPU_REG const *ptr)
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{
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int exp = exponent(ptr);
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if ( exp == EXP_BIAS+EXP_UNDER )
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return TW_Denormal;
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else if ( exp != EXP_BIAS+EXP_OVER )
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return TW_NaN;
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else if ( (ptr->sigh == 0x80000000) && (ptr->sigl == 0) )
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return TW_Infinity;
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return TW_NaN;
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}
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int isNaN(FPU_REG const *ptr)
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{
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return ( (exponent(ptr) == EXP_BIAS+EXP_OVER)
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&& !((ptr->sigh == 0x80000000) && (ptr->sigl == 0)) );
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}
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int FPU_empty_i(int stnr)
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{
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int regnr = (top+stnr) & 7;
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return ((fpu_tag_word >> (regnr*2)) & 3) == TAG_Empty;
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}
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int FPU_stackoverflow(FPU_REG **st_new_ptr)
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{
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*st_new_ptr = &st(-1);
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return ((fpu_tag_word >> (((top - 1) & 7)*2)) & 3) != TAG_Empty;
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}
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void FPU_copy_to_regi(FPU_REG const *r, u_char tag, int stnr)
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{
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reg_copy(r, &st(stnr));
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FPU_settagi(stnr, tag);
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}
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void FPU_copy_to_reg1(FPU_REG const *r, u_char tag)
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{
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reg_copy(r, &st(1));
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FPU_settagi(1, tag);
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}
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void FPU_copy_to_reg0(FPU_REG const *r, u_char tag)
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{
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int regnr = top;
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regnr &= 7;
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reg_copy(r, &st(0));
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fpu_tag_word &= ~(3 << (regnr*2));
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fpu_tag_word |= (tag & 3) << (regnr*2);
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}
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