ref: 9607be7406fb7c452bd13b92ea2c8178083c189a
dir: /operators.c/
#include "llt.h"
#include "ieee754.h"
#if defined(__plan9__)
double trunc(double x)
{
modf(x, &x);
return x;
}
#define fpart(x) modf(x, nil)
#else
#define fpart(x) ((x) - trunc(x))
#endif
// given a number, determine an appropriate type for storing it
// simpler version implementing a smaller preferred type repertoire
numerictype_t effective_numerictype(double r)
{
double fp;
fp = fpart(r);
if (fp != 0 || r > (double)INT64_MAX || r < INT64_MIN)
return T_DOUBLE;
else if (r >= INT32_MIN && r <= INT32_MAX)
return T_INT32;
else if (r <= (double)INT64_MAX)
return T_INT64;
return T_UINT64;
}
double conv_to_double(void *data, numerictype_t tag)
{
double d=0;
switch (tag) {
case T_INT8: d = (double)*(int8_t*)data; break;
case T_UINT8: d = (double)*(uint8_t*)data; break;
case T_INT16: d = (double)*(int16_t*)data; break;
case T_UINT16: d = (double)*(uint16_t*)data; break;
case T_INT32: d = (double)*(int32_t*)data; break;
case T_UINT32: d = (double)*(uint32_t*)data; break;
case T_INT64:
d = (double)*(int64_t*)data;
if (d > 0 && *(int64_t*)data < 0) // can happen!
d = -d;
break;
case T_UINT64: d = (double)*(uint64_t*)data; break;
case T_FLOAT: d = (double)*(float*)data; break;
case T_DOUBLE: return *(double*)data;
}
return d;
}
void conv_from_double(void *dest, double d, numerictype_t tag)
{
switch (tag) {
case T_INT8: *(int8_t*)dest = d; break;
case T_UINT8: *(uint8_t*)dest = d; break;
case T_INT16: *(int16_t*)dest = d; break;
case T_UINT16: *(uint16_t*)dest = d; break;
case T_INT32: *(int32_t*)dest = d; break;
case T_UINT32: *(uint32_t*)dest = d; break;
case T_INT64:
*(int64_t*)dest = d;
if (d > 0 && *(int64_t*)dest < 0) // 0x8000000000000000 is a bitch
*(int64_t*)dest = INT64_MAX;
break;
case T_UINT64: *(uint64_t*)dest = (int64_t)d; break;
case T_FLOAT: *(float*)dest = d; break;
case T_DOUBLE: *(double*)dest = d; break;
}
}
#define CONV_TO_INTTYPE(name, ctype) \
ctype conv_to_##name(void *data, numerictype_t tag) \
{ \
switch (tag) { \
case T_INT8: return *(int8_t*)data; \
case T_UINT8: return *(uint8_t*)data; \
case T_INT16: return *(int16_t*)data; \
case T_UINT16: return *(uint16_t*)data; \
case T_INT32: return *(int32_t*)data; \
case T_UINT32: return *(uint32_t*)data; \
case T_INT64: return *(int64_t*)data; \
case T_UINT64: return *(uint64_t*)data; \
case T_FLOAT: return *(float*)data; \
case T_DOUBLE: return *(double*)data; \
} \
return 0; \
}
CONV_TO_INTTYPE(int64, int64_t)
CONV_TO_INTTYPE(int32, int32_t)
CONV_TO_INTTYPE(uint32, uint32_t)
// this is needed to work around an UB casting negative
// floats and doubles to uint64. you need to cast to int64
// first.
uint64_t conv_to_uint64(void *data, numerictype_t tag)
{
int64_t s;
switch (tag) {
case T_INT8: return *(int8_t*)data; break;
case T_UINT8: return *(uint8_t*)data; break;
case T_INT16: return *(int16_t*)data; break;
case T_UINT16: return *(uint16_t*)data; break;
case T_INT32: return *(int32_t*)data; break;
case T_UINT32: return *(uint32_t*)data; break;
case T_INT64: return *(int64_t*)data; break;
case T_UINT64: return *(uint64_t*)data; break;
case T_FLOAT:
if (*(float*)data >= 0)
return *(float*)data;
s = *(float*)data;
return s;
case T_DOUBLE:
if (*(double*)data >= 0)
return *(double*)data;
s = *(double*)data;
return s;
}
return 0;
}
int cmp_same_lt(void *a, void *b, numerictype_t tag)
{
switch (tag) {
case T_INT8: return *(int8_t*)a < *(int8_t*)b;
case T_UINT8: return *(uint8_t*)a < *(uint8_t*)b;
case T_INT16: return *(int16_t*)a < *(int16_t*)b;
case T_UINT16: return *(uint16_t*)a < *(uint16_t*)b;
case T_INT32: return *(int32_t*)a < *(int32_t*)b;
case T_UINT32: return *(uint32_t*)a < *(uint32_t*)b;
case T_INT64: return *(int64_t*)a < *(int64_t*)b;
case T_UINT64: return *(uint64_t*)a < *(uint64_t*)b;
case T_FLOAT: return *(float*)a < *(float*)b;
case T_DOUBLE: return *(double*)a < *(double*)b;
}
return 0;
}
int cmp_same_eq(void *a, void *b, numerictype_t tag)
{
switch (tag) {
case T_INT8: return *(int8_t*)a == *(int8_t*)b;
case T_UINT8: return *(uint8_t*)a == *(uint8_t*)b;
case T_INT16: return *(int16_t*)a == *(int16_t*)b;
case T_UINT16: return *(uint16_t*)a == *(uint16_t*)b;
case T_INT32: return *(int32_t*)a == *(int32_t*)b;
case T_UINT32: return *(uint32_t*)a == *(uint32_t*)b;
case T_INT64: return *(int64_t*)a == *(int64_t*)b;
case T_UINT64: return *(uint64_t*)a == *(uint64_t*)b;
case T_FLOAT: return *(float*)a == *(float*)b;
case T_DOUBLE: return *(double*)a == *(double*)b;
}
return 0;
}
int cmp_lt(void *a, numerictype_t atag, void *b, numerictype_t btag)
{
if (atag==btag)
return cmp_same_lt(a, b, atag);
double da = conv_to_double(a, atag);
double db = conv_to_double(b, btag);
// casting to double will only get the wrong answer for big int64s
// that differ in low bits
if (da < db && !isnan(da) && !isnan(db))
return 1;
if (db < da)
return 0;
if (atag == T_UINT64) {
if (btag == T_INT64) {
if (*(int64_t*)b >= 0)
return (*(uint64_t*)a < (uint64_t)*(int64_t*)b);
return ((int64_t)*(uint64_t*)a < *(int64_t*)b);
}
else if (btag == T_DOUBLE) {
if (db != db) return 0;
return (*(uint64_t*)a < (uint64_t)*(double*)b);
}
}
else if (atag == T_INT64) {
if (btag == T_UINT64) {
if (*(int64_t*)a >= 0)
return ((uint64_t)*(int64_t*)a < *(uint64_t*)b);
return (*(int64_t*)a < (int64_t)*(uint64_t*)b);
}
else if (btag == T_DOUBLE) {
if (db != db) return 0;
return (*(int64_t*)a < (int64_t)*(double*)b);
}
}
if (btag == T_UINT64) {
if (atag == T_DOUBLE) {
if (da != da) return 0;
return (*(uint64_t*)b > (uint64_t)*(double*)a);
}
}
else if (btag == T_INT64) {
if (atag == T_DOUBLE) {
if (da != da) return 0;
return (*(int64_t*)b > (int64_t)*(double*)a);
}
}
return 0;
}
int cmp_eq(void *a, numerictype_t atag, void *b, numerictype_t btag,
int equalnans)
{
union { double d; int64_t i64; } u, v;
if (atag==btag && (!equalnans || atag < T_FLOAT))
return cmp_same_eq(a, b, atag);
double da = conv_to_double(a, atag);
double db = conv_to_double(b, btag);
if ((int)atag >= T_FLOAT && (int)btag >= T_FLOAT) {
if (equalnans) {
u.d = da; v.d = db;
return u.i64 == v.i64;
}
return (da == db);
}
if (da != db)
return 0;
if (atag == T_UINT64) {
// this is safe because if a had been bigger than INT64_MAX,
// we would already have concluded that it's bigger than b.
if (btag == T_INT64)
return ((int64_t)*(uint64_t*)a == *(int64_t*)b);
else if (btag == T_DOUBLE)
return (*(uint64_t*)a == (uint64_t)(int64_t)*(double*)b);
}
else if (atag == T_INT64) {
if (btag == T_UINT64)
return (*(int64_t*)a == (int64_t)*(uint64_t*)b);
else if (btag == T_DOUBLE)
return (*(int64_t*)a == (int64_t)*(double*)b);
}
else if (btag == T_UINT64) {
if (atag == T_INT64)
return ((int64_t)*(uint64_t*)b == *(int64_t*)a);
else if (atag == T_DOUBLE)
return (*(uint64_t*)b == (uint64_t)(int64_t)*(double*)a);
}
else if (btag == T_INT64) {
if (atag == T_UINT64)
return (*(int64_t*)b == (int64_t)*(uint64_t*)a);
else if (atag == T_DOUBLE)
return (*(int64_t*)b == (int64_t)*(double*)a);
}
return 1;
}