diff --git a/py/compile.c b/py/compile.c index 3273abe40e..44b37b9342 100644 --- a/py/compile.c +++ b/py/compile.c @@ -17,7 +17,7 @@ #include "obj.h" #include "compile.h" #include "runtime.h" -#include "intdivmod.h" +#include "smallint.h" // TODO need to mangle __attr names @@ -143,10 +143,10 @@ mp_parse_node_t fold_constants(mp_parse_node_t pn) { } else if (MP_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], MP_TOKEN_OP_SLASH)) { ; // pass } else if (MP_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], MP_TOKEN_OP_PERCENT)) { - pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, python_modulo(arg0, arg1)); + pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, mp_small_int_modulo(arg0, arg1)); } else if (MP_PARSE_NODE_IS_TOKEN_KIND(pns->nodes[1], MP_TOKEN_OP_DBL_SLASH)) { if (arg1 != 0) { - pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, python_floor_divide(arg0, arg1)); + pn = mp_parse_node_new_leaf(MP_PARSE_NODE_SMALL_INT, mp_small_int_floor_divide(arg0, arg1)); } } else { // shouldn't happen diff --git a/py/intdivmod.c b/py/intdivmod.c deleted file mode 100644 index 4cb363b511..0000000000 --- a/py/intdivmod.c +++ /dev/null @@ -1,24 +0,0 @@ -#include "mpconfig.h" - -machine_int_t python_modulo(machine_int_t dividend, machine_int_t divisor) { - machine_int_t lsign = (dividend >= 0) ? 1 :-1; - machine_int_t rsign = (divisor >= 0) ? 1 :-1; - dividend %= divisor; - if (lsign != rsign) { - dividend += divisor; - } - return dividend; -} - - -machine_int_t python_floor_divide(machine_int_t num, machine_int_t denom) { - machine_int_t lsign = num > 0 ? 1 : -1; - machine_int_t rsign = denom > 0 ? 1 : -1; - if (lsign == -1) {num *= -1;} - if (rsign == -1) {denom *= -1;} - if (lsign != rsign){ - return - ( num + denom - 1) / denom; - } else { - return num / denom; - } -} diff --git a/py/intdivmod.h b/py/intdivmod.h deleted file mode 100644 index 7716bd21e9..0000000000 --- a/py/intdivmod.h +++ /dev/null @@ -1,4 +0,0 @@ -// Functions for integer modulo and floor division - -machine_int_t python_modulo(machine_int_t dividend, machine_int_t divisor); -machine_int_t python_floor_divide(machine_int_t num, machine_int_t denom); diff --git a/py/objint_mpz.c b/py/objint_mpz.c index 25a069cf93..d338428135 100644 --- a/py/objint_mpz.c +++ b/py/objint_mpz.c @@ -113,7 +113,7 @@ mp_obj_t int_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) { case MP_BINARY_OP_INPLACE_FLOOR_DIVIDE: { mpz_t rem; mpz_init_zero(&rem); mpz_divmod_inpl(&res->mpz, &rem, zlhs, zrhs); - if (zlhs->neg != zrhs->neg) { + if (zlhs->neg != zrhs->neg) { if (!mpz_is_zero(&rem)) { mpz_t mpzone; mpz_init_from_int(&mpzone, -1); mpz_add_inpl(&res->mpz, &res->mpz, &mpzone); @@ -127,8 +127,8 @@ mp_obj_t int_binary_op(int op, mp_obj_t lhs_in, mp_obj_t rhs_in) { mpz_t quo; mpz_init_zero(&quo); mpz_divmod_inpl(&quo, &res->mpz, zlhs, zrhs); mpz_deinit(&quo); - // Check signs and do Python style modulo - if (zlhs->neg != zrhs->neg) { + // Check signs and do Python style modulo + if (zlhs->neg != zrhs->neg) { mpz_add_inpl(&res->mpz, &res->mpz, zrhs); } break; diff --git a/py/py.mk b/py/py.mk index 059029274e..a08997332b 100644 --- a/py/py.mk +++ b/py/py.mk @@ -84,7 +84,7 @@ PY_O_BASENAME = \ vm.o \ showbc.o \ repl.o \ - intdivmod.o \ + smallint.o \ pfenv.o \ # prepend the build destination prefix to the py object files diff --git a/py/runtime.c b/py/runtime.c index a5afe0e750..a5f45a2fb4 100644 --- a/py/runtime.c +++ b/py/runtime.c @@ -16,7 +16,7 @@ #include "builtin.h" #include "builtintables.h" #include "bc.h" -#include "intdivmod.h" +#include "smallint.h" #include "objgenerator.h" #if 0 // print debugging info @@ -289,7 +289,7 @@ mp_obj_t mp_binary_op(int op, mp_obj_t lhs, mp_obj_t rhs) { // If long long type exists and is larger than machine_int_t, then // we can use the following code to perform overflow-checked multiplication. - // Otherwise (eg in x64 case) we must use the branching code below. + // Otherwise (eg in x64 case) we must use mp_small_int_mul_overflow. #if 0 // compute result using long long precision long long res = (long long)lhs_val * (long long)rhs_val; @@ -302,36 +302,14 @@ mp_obj_t mp_binary_op(int op, mp_obj_t lhs, mp_obj_t rhs) { } #endif - if (lhs_val > 0) { // lhs_val is positive - if (rhs_val > 0) { // lhs_val and rhs_val are positive - if (lhs_val > (MP_SMALL_INT_MAX / rhs_val)) { - goto mul_overflow; - } - } else { // lhs_val positive, rhs_val nonpositive - if (rhs_val < (MP_SMALL_INT_MIN / lhs_val)) { - goto mul_overflow; - } - } // lhs_val positive, rhs_val nonpositive - } else { // lhs_val is nonpositive - if (rhs_val > 0) { // lhs_val is nonpositive, rhs_val is positive - if (lhs_val < (MP_SMALL_INT_MIN / rhs_val)) { - goto mul_overflow; - } - } else { // lhs_val and rhs_val are nonpositive - if (lhs_val != 0 && rhs_val < (MP_SMALL_INT_MAX / lhs_val)) { - goto mul_overflow; - } - } // End if lhs_val and rhs_val are nonpositive - } // End if lhs_val is nonpositive - - // use standard precision - return MP_OBJ_NEW_SMALL_INT(lhs_val * rhs_val); - - mul_overflow: - // use higher precision - lhs = mp_obj_new_int_from_ll(lhs_val); - goto generic_binary_op; - + if (mp_small_int_mul_overflow(lhs_val, rhs_val)) { + // use higher precision + lhs = mp_obj_new_int_from_ll(lhs_val); + goto generic_binary_op; + } else { + // use standard precision + return MP_OBJ_NEW_SMALL_INT(lhs_val * rhs_val); + } break; } case MP_BINARY_OP_FLOOR_DIVIDE: @@ -339,7 +317,7 @@ mp_obj_t mp_binary_op(int op, mp_obj_t lhs, mp_obj_t rhs) { if (rhs_val == 0) { goto zero_division; } - lhs_val = python_floor_divide(lhs_val, rhs_val); + lhs_val = mp_small_int_floor_divide(lhs_val, rhs_val); break; #if MICROPY_ENABLE_FLOAT @@ -352,11 +330,11 @@ mp_obj_t mp_binary_op(int op, mp_obj_t lhs, mp_obj_t rhs) { #endif case MP_BINARY_OP_MODULO: - case MP_BINARY_OP_INPLACE_MODULO: - { - lhs_val = python_modulo(lhs_val, rhs_val); + case MP_BINARY_OP_INPLACE_MODULO: { + lhs_val = mp_small_int_modulo(lhs_val, rhs_val); break; } + case MP_BINARY_OP_POWER: case MP_BINARY_OP_INPLACE_POWER: if (rhs_val < 0) { @@ -370,21 +348,19 @@ mp_obj_t mp_binary_op(int op, mp_obj_t lhs, mp_obj_t rhs) { machine_int_t ans = 1; while (rhs_val > 0) { if (rhs_val & 1) { - machine_int_t old = ans; - ans *= lhs_val; - if (ans < old) { + if (mp_small_int_mul_overflow(ans, lhs_val)) { goto power_overflow; } + ans *= lhs_val; } if (rhs_val == 1) { break; } rhs_val /= 2; - machine_int_t old = lhs_val; - lhs_val *= lhs_val; - if (lhs_val < old) { + if (mp_small_int_mul_overflow(lhs_val, lhs_val)) { goto power_overflow; } + lhs_val *= lhs_val; } lhs_val = ans; } diff --git a/py/smallint.c b/py/smallint.c new file mode 100644 index 0000000000..ac0cf2f5f9 --- /dev/null +++ b/py/smallint.c @@ -0,0 +1,53 @@ +#include "misc.h" +#include "mpconfig.h" +#include "qstr.h" +#include "obj.h" + +bool mp_small_int_mul_overflow(machine_int_t x, machine_int_t y) { + // Check for multiply overflow; see CERT INT32-C + if (x > 0) { // x is positive + if (y > 0) { // x and y are positive + if (x > (MP_SMALL_INT_MAX / y)) { + return true; + } + } else { // x positive, y nonpositive + if (y < (MP_SMALL_INT_MIN / x)) { + return true; + } + } // x positive, y nonpositive + } else { // x is nonpositive + if (y > 0) { // x is nonpositive, y is positive + if (x < (MP_SMALL_INT_MIN / y)) { + return true; + } + } else { // x and y are nonpositive + if (x != 0 && y < (MP_SMALL_INT_MAX / x)) { + return true; + } + } // End if x and y are nonpositive + } // End if x is nonpositive + return false; +} + +machine_int_t mp_small_int_modulo(machine_int_t dividend, machine_int_t divisor) { + machine_int_t lsign = (dividend >= 0) ? 1 :-1; + machine_int_t rsign = (divisor >= 0) ? 1 :-1; + dividend %= divisor; + if (lsign != rsign) { + dividend += divisor; + } + return dividend; +} + + +machine_int_t mp_small_int_floor_divide(machine_int_t num, machine_int_t denom) { + machine_int_t lsign = num > 0 ? 1 : -1; + machine_int_t rsign = denom > 0 ? 1 : -1; + if (lsign == -1) {num *= -1;} + if (rsign == -1) {denom *= -1;} + if (lsign != rsign){ + return - ( num + denom - 1) / denom; + } else { + return num / denom; + } +} diff --git a/py/smallint.h b/py/smallint.h new file mode 100644 index 0000000000..14234fa7b8 --- /dev/null +++ b/py/smallint.h @@ -0,0 +1,5 @@ +// Functions for small integer arithmetic + +bool mp_small_int_mul_overflow(machine_int_t x, machine_int_t y); +machine_int_t mp_small_int_modulo(machine_int_t dividend, machine_int_t divisor); +machine_int_t mp_small_int_floor_divide(machine_int_t num, machine_int_t denom);