54 lines
1.6 KiB
C
54 lines
1.6 KiB
C
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#include "misc.h"
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#include "mpconfig.h"
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#include "qstr.h"
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#include "obj.h"
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bool mp_small_int_mul_overflow(machine_int_t x, machine_int_t y) {
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// Check for multiply overflow; see CERT INT32-C
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if (x > 0) { // x is positive
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if (y > 0) { // x and y are positive
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if (x > (MP_SMALL_INT_MAX / y)) {
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return true;
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}
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} else { // x positive, y nonpositive
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if (y < (MP_SMALL_INT_MIN / x)) {
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return true;
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}
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} // x positive, y nonpositive
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} else { // x is nonpositive
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if (y > 0) { // x is nonpositive, y is positive
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if (x < (MP_SMALL_INT_MIN / y)) {
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return true;
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}
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} else { // x and y are nonpositive
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if (x != 0 && y < (MP_SMALL_INT_MAX / x)) {
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return true;
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}
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} // End if x and y are nonpositive
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} // End if x is nonpositive
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return false;
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}
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machine_int_t mp_small_int_modulo(machine_int_t dividend, machine_int_t divisor) {
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machine_int_t lsign = (dividend >= 0) ? 1 :-1;
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machine_int_t rsign = (divisor >= 0) ? 1 :-1;
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dividend %= divisor;
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if (lsign != rsign) {
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dividend += divisor;
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}
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return dividend;
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}
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machine_int_t mp_small_int_floor_divide(machine_int_t num, machine_int_t denom) {
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machine_int_t lsign = num > 0 ? 1 : -1;
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machine_int_t rsign = denom > 0 ? 1 : -1;
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if (lsign == -1) {num *= -1;}
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if (rsign == -1) {denom *= -1;}
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if (lsign != rsign){
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return - ( num + denom - 1) / denom;
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} else {
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return num / denom;
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}
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}
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