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py: Implement divmod, % and proper // for floating point.

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Tested and working on unix and pyboard.
This commit is contained in:
Damien George 2014-09-13 18:43:09 +01:00
parent 5c6783496d
commit 8594ce2280
8 changed files with 150 additions and 18 deletions
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70
lib/libm/fmodf.c Normal file
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@ -0,0 +1,70 @@
/*****************************************************************************/
/*****************************************************************************/
// fmodf from musl-0.9.15
/*****************************************************************************/
/*****************************************************************************/
#include "libm.h"
float fmodf(float x, float y)
{
union {float f; uint32_t i;} ux = {x}, uy = {y};
int ex = ux.i>>23 & 0xff;
int ey = uy.i>>23 & 0xff;
uint32_t sx = ux.i & 0x80000000;
uint32_t i;
uint32_t uxi = ux.i;
if (uy.i<<1 == 0 || isnan(y) || ex == 0xff)
return (x*y)/(x*y);
if (uxi<<1 <= uy.i<<1) {
if (uxi<<1 == uy.i<<1)
return 0*x;
return x;
}
/* normalize x and y */
if (!ex) {
for (i = uxi<<9; i>>31 == 0; ex--, i <<= 1);
uxi <<= -ex + 1;
} else {
uxi &= -1U >> 9;
uxi |= 1U << 23;
}
if (!ey) {
for (i = uy.i<<9; i>>31 == 0; ey--, i <<= 1);
uy.i <<= -ey + 1;
} else {
uy.i &= -1U >> 9;
uy.i |= 1U << 23;
}
/* x mod y */
for (; ex > ey; ex--) {
i = uxi - uy.i;
if (i >> 31 == 0) {
if (i == 0)
return 0*x;
uxi = i;
}
uxi <<= 1;
}
i = uxi - uy.i;
if (i >> 31 == 0) {
if (i == 0)
return 0*x;
uxi = i;
}
for (; uxi>>23 == 0; uxi <<= 1, ex--);
/* scale result up */
if (ex > 0) {
uxi -= 1U << 23;
uxi |= (uint32_t)ex << 23;
} else {
uxi >>= -ex + 1;
}
uxi |= sx;
ux.i = uxi;
return ux.f;
}

1
lib/libm/math.c
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@ -117,7 +117,6 @@ float acoshf(float x) { return 0.0; }
float asinhf(float x) { return 0.0; }
float atanhf(float x) { return 0.0; }
float tanf(float x) { return 0.0; }
float fmodf(float x, float y) { return 0.0; }
float tgammaf(float x) { return 0.0; }
float lgammaf(float x) { return 0.0; }
float erff(float x) { return 0.0; }

19
py/builtin.c
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@ -242,13 +242,32 @@ STATIC mp_obj_t mp_builtin_dir(mp_uint_t n_args, const mp_obj_t *args) {
MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_builtin_dir_obj, 0, 1, mp_builtin_dir);
STATIC mp_obj_t mp_builtin_divmod(mp_obj_t o1_in, mp_obj_t o2_in) {
// TODO handle big int
if (MP_OBJ_IS_SMALL_INT(o1_in) && MP_OBJ_IS_SMALL_INT(o2_in)) {
mp_int_t i1 = MP_OBJ_SMALL_INT_VALUE(o1_in);
mp_int_t i2 = MP_OBJ_SMALL_INT_VALUE(o2_in);
if (i2 == 0) {
zero_division_error:
nlr_raise(mp_obj_new_exception_msg(&mp_type_ZeroDivisionError, "division by zero"));
}
mp_obj_t args[2];
args[0] = MP_OBJ_NEW_SMALL_INT(i1 / i2);
args[1] = MP_OBJ_NEW_SMALL_INT(i1 % i2);
return mp_obj_new_tuple(2, args);
#if MICROPY_PY_BUILTINS_FLOAT
} else if (MP_OBJ_IS_TYPE(o1_in, &mp_type_float) || MP_OBJ_IS_TYPE(o2_in, &mp_type_float)) {
mp_float_t f1 = mp_obj_get_float(o1_in);
mp_float_t f2 = mp_obj_get_float(o2_in);
if (f2 == 0.0) {
goto zero_division_error;
}
mp_obj_float_divmod(&f1, &f2);
mp_obj_t tuple[2] = {
mp_obj_new_float(f1),
mp_obj_new_float(f2),
};
return mp_obj_new_tuple(2, tuple);
#endif
} else {
nlr_raise(mp_obj_new_exception_msg_varg(&mp_type_TypeError, "unsupported operand type(s) for divmod(): '%s' and '%s'", mp_obj_get_type_str(o1_in), mp_obj_get_type_str(o2_in)));
}

1
py/obj.h
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@ -487,6 +487,7 @@ typedef struct _mp_obj_float_t {
} mp_obj_float_t;
mp_float_t mp_obj_float_get(mp_obj_t self_in);
mp_obj_t mp_obj_float_binary_op(mp_uint_t op, mp_float_t lhs_val, mp_obj_t rhs); // can return MP_OBJ_NULL if op not supported
void mp_obj_float_divmod(mp_float_t *x, mp_float_t *y);
// complex
void mp_obj_complex_get(mp_obj_t self_in, mp_float_t *real, mp_float_t *imag);

58
py/objfloat.c
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@ -143,14 +143,16 @@ mp_obj_t mp_obj_float_binary_op(mp_uint_t op, mp_float_t lhs_val, mp_obj_t rhs_i
case MP_BINARY_OP_INPLACE_SUBTRACT: lhs_val -= rhs_val; break;
case MP_BINARY_OP_MULTIPLY:
case MP_BINARY_OP_INPLACE_MULTIPLY: lhs_val *= rhs_val; break;
// TODO: verify that C floor matches Python semantics
case MP_BINARY_OP_FLOOR_DIVIDE:
case MP_BINARY_OP_INPLACE_FLOOR_DIVIDE:
if (rhs_val == 0) {
zero_division_error:
nlr_raise(mp_obj_new_exception_msg(&mp_type_ZeroDivisionError, "float division by zero"));
nlr_raise(mp_obj_new_exception_msg(&mp_type_ZeroDivisionError, "division by zero"));
}
lhs_val = MICROPY_FLOAT_C_FUN(floor)(lhs_val / rhs_val);
// Python specs require that x == (x//y)*y + (x%y) so we must
// call divmod to compute the correct floor division, which
// returns the floor divide in lhs_val.
mp_obj_float_divmod(&lhs_val, &rhs_val);
break;
case MP_BINARY_OP_TRUE_DIVIDE:
case MP_BINARY_OP_INPLACE_TRUE_DIVIDE:
@ -159,6 +161,21 @@ mp_obj_t mp_obj_float_binary_op(mp_uint_t op, mp_float_t lhs_val, mp_obj_t rhs_i
}
lhs_val /= rhs_val;
break;
case MP_BINARY_OP_MODULO:
case MP_BINARY_OP_INPLACE_MODULO:
if (rhs_val == 0) {
goto zero_division_error;
}
lhs_val = MICROPY_FLOAT_C_FUN(fmod)(lhs_val, rhs_val);
// Python specs require that mod has same sign as second operand
if (lhs_val == 0.0) {
lhs_val = MICROPY_FLOAT_C_FUN(copysign)(0.0, rhs_val);
} else {
if ((lhs_val < 0.0) != (rhs_val < 0.0)) {
lhs_val += rhs_val;
}
}
break;
case MP_BINARY_OP_POWER:
case MP_BINARY_OP_INPLACE_POWER: lhs_val = MICROPY_FLOAT_C_FUN(pow)(lhs_val, rhs_val); break;
case MP_BINARY_OP_LESS: return MP_BOOL(lhs_val < rhs_val);
@ -173,4 +190,39 @@ mp_obj_t mp_obj_float_binary_op(mp_uint_t op, mp_float_t lhs_val, mp_obj_t rhs_i
return mp_obj_new_float(lhs_val);
}
void mp_obj_float_divmod(mp_float_t *x, mp_float_t *y) {
// logic here follows that of CPython
// https://docs.python.org/3/reference/expressions.html#binary-arithmetic-operations
// x == (x//y)*y + (x%y)
// divmod(x, y) == (x//y, x%y)
mp_float_t mod = MICROPY_FLOAT_C_FUN(fmod)(*x, *y);
mp_float_t div = (*x - mod) / *y;
// Python specs require that mod has same sign as second operand
if (mod == 0.0) {
mod = MICROPY_FLOAT_C_FUN(copysign)(0.0, *y);
} else {
if ((mod < 0.0) != (*y < 0.0)) {
mod += *y;
div -= 1.0;
}
}
mp_float_t floordiv;
if (div == 0.0) {
// if division is zero, take the correct sign of zero
floordiv = MICROPY_FLOAT_C_FUN(copysign)(0.0, *x / *y);
} else {
// Python specs require that x == (x//y)*y + (x%y)
floordiv = MICROPY_FLOAT_C_FUN(floor)(div);
if (div - floordiv > 0.5) {
floordiv += 1.0;
}
}
// return results
*x = floordiv;
*y = mod;
}
#endif // MICROPY_PY_BUILTINS_FLOAT

1
stmhal/Makefile
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@ -67,6 +67,7 @@ SRC_LIB = $(addprefix lib/,\
libm/asinfacosf.c \
libm/atanf.c \
libm/atan2f.c \
libm/fmodf.c \
)
SRC_C = \

14
tests/float/modulo.py
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@ -1,14 +0,0 @@
# check modulo matches python definition
# TODO we currenty fail with this
if False:
print(1.23456 % 0.7)
print(-1.23456 % 0.7)
print(1.23456 % -0.7)
print(-1.23456 % -0.7)
a = 1.23456
b = 0.7
print(a % b)
print(a % -b)
print(-a % b)
print(-a % -b)

4
tests/run-tests
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@ -33,6 +33,10 @@ def run_tests(pyb, tests, args):
if os.getenv('TRAVIS') == 'true':
skip_tests.add('basics/memoryerror.py')
# Some tests shouldn't be run on pyboard
if pyb is not None:
skip_tests.add('float/float_divmod.py') # tested by float/float_divmod_relaxed.py instead
# Some tests are known to fail with native emitter
# Remove them from the below when they work
if args.emit == 'native':