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Cream of the Crop 1
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Cream of the Crop 1.iso
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PROGRAM
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DJEMU106.ARJ
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COMPARE.CC
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C/C++ Source or Header
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1992-04-08
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2KB
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90 lines
#include "emu.h"
#include "compare.h"
#include "const.h"
#define NAN_NONE 0
#define NAN_SNAN 1
#define NAN_QNAN 2
extern "C" void djshld(void *);
int nan_type(reg& r)
{
if (r.exp != EXP_MAX)
return NAN_NONE;
if (r.sigh & 0x40000000)
return NAN_QNAN;
return NAN_SNAN;
}
int compare(reg& a, reg& b)
{
int a_inf, b_inf; // 0=no, 1=pos, -1=neg
a_inf = 0;
if (val_same(a, CONST_PINF))
a_inf = 1;
else if (val_same(a, CONST_NINF))
a_inf = -1;
b_inf = 0;
if (val_same(b, CONST_PINF))
b_inf = 1;
else if (val_same(b, CONST_NINF))
b_inf = -1;
if (a_inf || b_inf)
{
if (a_inf == 1)
if (b_inf == 1)
return COMP_A_EQ_B;
else
return COMP_A_GT_B;
if (b_inf == 1)
return COMP_A_LT_B;
if (a_inf == -1)
if (b_inf == -1)
return COMP_A_EQ_B;
else
return COMP_A_LT_B;
if (b_inf == -1)
return COMP_A_GT_B;
}
int a_nan = nan_type(a);
int b_nan = nan_type(b);
if (a_nan || b_nan)
{
if ((a_nan == NAN_SNAN) || (b_nan == NAN_SNAN))
return COMP_NOCOMP | COMP_SNAN | COMP_NAN;
return COMP_NOCOMP | COMP_NAN;
}
if (a.sign != b.sign)
{
if ((a.tag == TW_Z) && (b.tag == TW_Z))
return COMP_A_EQ_B;
if (a.sign == SIGN_POS)
return COMP_A_GT_B;
return COMP_A_LT_B;
}
while (!(a.sigh & 0x80000000))
{
if (!a.exp)
break;
djshld(&a.sigl);
a.exp--;
}
while (!(b.sigh & 0x80000000))
{
if (!b.exp)
break;
djshld(&b.sigl);
b.exp--;
}
int diff = a.exp - b.exp;
if (diff == 0) diff = a.sigh - b.sigh;
if (diff == 0) diff = a.sigl - b.sigl;
if (a.sign == SIGN_NEG)
diff = -diff;
if (diff > 0) return COMP_A_GT_B;
if (diff < 0) return COMP_A_LT_B;
return COMP_A_EQ_B;
}