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Commit 0c7e3e62 authored by Stefan Behnel's avatar Stefan Behnel
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Avoid useless "div by zero" checks in optimised constant division code. Also... 

Avoid useless "div by zero" checks in optimised constant division code. Also avoid using a (named) C macro where code generation will do.
See GH-2820.
parent 13617b61
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Showing with 33 additions and 38 deletions
Cython/Utility/Optimize.c
View file @ 0c7e3e62
...@@ -805,7 +805,6 @@ static {{c_ret_type}} __Pyx_PyInt_{{'' if ret_type.is_pyobject else 'Bool'}}{{op ...@@ -805,7 +805,6 @@ static {{c_ret_type}} __Pyx_PyInt_{{'' if ret_type.is_pyobject else 'Bool'}}{{op
{{py: return_false = 'Py_RETURN_FALSE' if ret_type.is_pyobject else 'return 0'}} {{py: return_false = 'Py_RETURN_FALSE' if ret_type.is_pyobject else 'return 0'}}
{{py: slot_name = {'TrueDivide': 'true_divide', 'FloorDivide': 'floor_divide'}.get(op, op.lower()) }} {{py: slot_name = {'TrueDivide': 'true_divide', 'FloorDivide': 'floor_divide'}.get(op, op.lower()) }}
{{py: cfunc_name = '__Pyx_PyInt_%s%s%s' % ('' if ret_type.is_pyobject else 'Bool', op, order)}} {{py: cfunc_name = '__Pyx_PyInt_%s%s%s' % ('' if ret_type.is_pyobject else 'Bool', op, order)}}
{{py: zerodiv_check = lambda operand, _cfunc_name=cfunc_name: '%s_ZeroDivisionError(%s)' % (_cfunc_name, operand)}}
{{py: {{py:
c_op = { c_op = {
'Add': '+', 'Subtract': '-', 'Multiply': '*', 'Remainder': '%', 'TrueDivide': '/', 'FloorDivide': '/', 'Add': '+', 'Subtract': '-', 'Multiply': '*', 'Remainder': '%', 'TrueDivide': '/', 'FloorDivide': '/',
...@@ -813,21 +812,19 @@ c_op = { ...@@ -813,21 +812,19 @@ c_op = {
'Eq': '==', 'Ne': '!=', 'Eq': '==', 'Ne': '!=',
}[op] }[op]
}} }}
{{py:
{{if op in ('TrueDivide', 'FloorDivide', 'Remainder')}} def zerodiv_check(operand, optype='integer', _is_mod=op == 'Remainder', _needs_check=(order == 'CObj' and c_op in '%/')):
#if PY_MAJOR_VERSION < 3 || CYTHON_USE_PYLONG_INTERNALS return (((
#define {{zerodiv_check('operand')}} \ 'if (unlikely(zerodivision_check && ((%s) == 0))) {'
if (unlikely(zerodivision_check && ((operand) == 0))) { \ ' PyErr_SetString(PyExc_ZeroDivisionError, "%s division%s by zero");'
PyErr_SetString(PyExc_ZeroDivisionError, "integer division{{if op == 'Remainder'}} or modulo{{endif}} by zero"); \ ' return NULL;'
return NULL; \ '}') % (operand, optype, ' or modulo' if _is_mod else '')
} ) if _needs_check else '')
#endif }}
{{endif}}
static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED long intval, int inplace, int zerodivision_check) { static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED long intval, int inplace, int zerodivision_check) {
// Prevent "unused" warnings. // Prevent "unused" warnings.
(void)inplace; (void)inplace; (void)zerodivision_check;
(void)zerodivision_check;
{{if op in ('Eq', 'Ne')}} {{if op in ('Eq', 'Ne')}}
if (op1 == op2) { if (op1 == op2) {
...@@ -927,7 +924,10 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED ...@@ -927,7 +924,10 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED
{{endif}} {{endif}}
// special cases for 0: + - * % / // | ^ & >> << // special cases for 0: + - * % / // | ^ & >> <<
if (unlikely(size == 0)) { if (unlikely(size == 0)) {
{{if order == 'CObj' and c_op in '+-|^>><<'}} {{if order == 'CObj' and c_op in '%/'}}
// division by zero!
{{zerodiv_check('0')}}
{{elif order == 'CObj' and c_op in '+-|^>><<'}}
// x == x+0 == x-0 == x|0 == x^0 == x>>0 == x<<0 // x == x+0 == x-0 == x|0 == x^0 == x>>0 == x<<0
return __Pyx_NewRef(op1); return __Pyx_NewRef(op1);
{{elif order == 'CObj' and c_op in '*&'}} {{elif order == 'CObj' and c_op in '*&'}}
...@@ -999,19 +999,16 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED ...@@ -999,19 +999,16 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED
return PyLong_Type.tp_as_number->nb_{{slot_name}}(op1, op2); return PyLong_Type.tp_as_number->nb_{{slot_name}}(op1, op2);
#endif #endif
{{elif c_op == '%'}} {{elif c_op == '%'}}
{{zerodiv_check('b')}}
// see ExprNodes.py :: mod_int_utility_code // see ExprNodes.py :: mod_int_utility_code
x = a % b; x = a % b;
x += ((x != 0) & ((x ^ b) < 0)) * b; x += ((x != 0) & ((x ^ b) < 0)) * b;
{{elif op == 'TrueDivide'}} {{elif op == 'TrueDivide'}}
{{zerodiv_check('b')}}
if ((8 * sizeof(long) <= 53 || likely(labs({{ival}}) <= ((PY_LONG_LONG)1 << 53))) if ((8 * sizeof(long) <= 53 || likely(labs({{ival}}) <= ((PY_LONG_LONG)1 << 53)))
|| __Pyx_sst_abs(size) <= 52 / PyLong_SHIFT) { || __Pyx_sst_abs(size) <= 52 / PyLong_SHIFT) {
return PyFloat_FromDouble((double)a / (double)b); return PyFloat_FromDouble((double)a / (double)b);
} }
return PyLong_Type.tp_as_number->nb_{{slot_name}}(op1, op2); return PyLong_Type.tp_as_number->nb_{{slot_name}}(op1, op2);
{{elif op == 'FloorDivide'}} {{elif op == 'FloorDivide'}}
{{zerodiv_check('b')}}
{ {
long q, r; long q, r;
// see ExprNodes.py :: div_int_utility_code // see ExprNodes.py :: div_int_utility_code
...@@ -1076,12 +1073,7 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED ...@@ -1076,12 +1073,7 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, CYTHON_UNUSED
} }
{{else}} {{else}}
double result; double result;
{{if op == 'TrueDivide'}} {{zerodiv_check('b', 'float')}}
if (unlikely(zerodivision_check && b == 0)) {
PyErr_SetString(PyExc_ZeroDivisionError, "float division by zero");
return NULL;
}
{{endif}}
// copied from floatobject.c in Py3.5: // copied from floatobject.c in Py3.5:
PyFPE_START_PROTECT("{{op.lower() if not op.endswith('Divide') else 'divide'}}", return NULL) PyFPE_START_PROTECT("{{op.lower() if not op.endswith('Divide') else 'divide'}}", return NULL)
result = ((double)a) {{c_op}} (double)b; result = ((double)a) {{c_op}} (double)b;
...@@ -1122,27 +1114,27 @@ static {{c_ret_type}} __Pyx_PyFloat_{{'' if ret_type.is_pyobject else 'Bool'}}{{ ...@@ -1122,27 +1114,27 @@ static {{c_ret_type}} __Pyx_PyFloat_{{'' if ret_type.is_pyobject else 'Bool'}}{{
{{py: return_false = 'Py_RETURN_FALSE' if ret_type.is_pyobject else 'return 0'}} {{py: return_false = 'Py_RETURN_FALSE' if ret_type.is_pyobject else 'return 0'}}
{{py: pyval, fval = ('op2', 'b') if order == 'CObj' else ('op1', 'a') }} {{py: pyval, fval = ('op2', 'b') if order == 'CObj' else ('op1', 'a') }}
{{py: cfunc_name = '__Pyx_PyFloat_%s%s%s' % ('' if ret_type.is_pyobject else 'Bool', op, order) }} {{py: cfunc_name = '__Pyx_PyFloat_%s%s%s' % ('' if ret_type.is_pyobject else 'Bool', op, order) }}
{{py: zerodiv_check = lambda operand, _cfunc_name=cfunc_name: '%s_ZeroDivisionError(%s)' % (_cfunc_name, operand)}}
{{py: {{py:
c_op = { c_op = {
'Add': '+', 'Subtract': '-', 'TrueDivide': '/', 'Divide': '/', 'Remainder': '%', 'Add': '+', 'Subtract': '-', 'TrueDivide': '/', 'Divide': '/', 'Remainder': '%',
'Eq': '==', 'Ne': '!=', 'Eq': '==', 'Ne': '!=',
}[op] }[op]
}} }}
{{py:
{{if order == 'CObj' and c_op in '%/'}} def zerodiv_check(operand, _is_mod=op == 'Remainder', _needs_check=(order == 'CObj' and c_op in '%/')):
#define {{zerodiv_check('operand')}} if (unlikely(zerodivision_check && ((operand) == 0))) { \ return (((
PyErr_SetString(PyExc_ZeroDivisionError, "float division{{if op == 'Remainder'}} or modulo{{endif}} by zero"); \ 'if (unlikely(zerodivision_check && ((%s) == 0.0))) {'
return NULL; \ ' PyErr_SetString(PyExc_ZeroDivisionError, "float division%s by zero");'
} ' return NULL;'
{{endif}} '}') % (operand, ' or modulo' if _is_mod else '')
) if _needs_check else '')
}}
static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatval, int inplace, int zerodivision_check) { static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatval, int inplace, int zerodivision_check) {
const double {{'a' if order == 'CObj' else 'b'}} = floatval; const double {{'a' if order == 'CObj' else 'b'}} = floatval;
double {{fval}}{{if op not in ('Eq', 'Ne')}}, result{{endif}}; double {{fval}}{{if op not in ('Eq', 'Ne')}}, result{{endif}};
// Prevent "unused" warnings. // Prevent "unused" warnings.
(void)inplace; (void)inplace; (void)zerodivision_check;
(void)zerodivision_check;
{{if op in ('Eq', 'Ne')}} {{if op in ('Eq', 'Ne')}}
if (op1 == op2) { if (op1 == op2) {
...@@ -1152,13 +1144,13 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv ...@@ -1152,13 +1144,13 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv
if (likely(PyFloat_CheckExact({{pyval}}))) { if (likely(PyFloat_CheckExact({{pyval}}))) {
{{fval}} = PyFloat_AS_DOUBLE({{pyval}}); {{fval}} = PyFloat_AS_DOUBLE({{pyval}});
{{if order == 'CObj' and c_op in '%/'}}{{zerodiv_check(fval)}}{{endif}} {{zerodiv_check(fval)}}
} else } else
#if PY_MAJOR_VERSION < 3 #if PY_MAJOR_VERSION < 3
if (likely(PyInt_CheckExact({{pyval}}))) { if (likely(PyInt_CheckExact({{pyval}}))) {
{{fval}} = (double) PyInt_AS_LONG({{pyval}}); {{fval}} = (double) PyInt_AS_LONG({{pyval}});
{{if order == 'CObj' and c_op in '%/'}}{{zerodiv_check(fval)}}{{endif}} {{zerodiv_check(fval)}}
} else } else
#endif #endif
...@@ -1167,7 +1159,7 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv ...@@ -1167,7 +1159,7 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv
const digit* digits = ((PyLongObject*){{pyval}})->ob_digit; const digit* digits = ((PyLongObject*){{pyval}})->ob_digit;
const Py_ssize_t size = Py_SIZE({{pyval}}); const Py_ssize_t size = Py_SIZE({{pyval}});
switch (size) { switch (size) {
case 0: {{if order == 'CObj' and c_op in '%/'}}{{zerodiv_check('0')}}{{else}}{{fval}} = 0.0;{{endif}} break; case 0: {{fval}} = 0.0; {{zerodiv_check(fval)}} break;
case -1: {{fval}} = -(double) digits[0]; break; case -1: {{fval}} = -(double) digits[0]; break;
case 1: {{fval}} = (double) digits[0]; break; case 1: {{fval}} = (double) digits[0]; break;
{{for _size in (2, 3, 4)}} {{for _size in (2, 3, 4)}}
...@@ -1199,7 +1191,11 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv ...@@ -1199,7 +1191,11 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv
{{else}} {{else}}
{{fval}} = PyLong_AsDouble({{pyval}}); {{fval}} = PyLong_AsDouble({{pyval}});
if (unlikely({{fval}} == -1.0 && PyErr_Occurred())) return NULL; if (unlikely({{fval}} == -1.0 && PyErr_Occurred())) return NULL;
{{if order == 'CObj' and c_op in '%/'}}{{zerodiv_check(fval)}}{{endif}} {{if zerodiv_check(fval)}}
#if !CYTHON_USE_PYLONG_INTERNALS
{{zerodiv_check(fval)}}
#endif
{{endif}}
{{endif}} {{endif}}
} }
} else { } else {
...@@ -1221,7 +1217,6 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv ...@@ -1221,7 +1217,6 @@ static {{c_ret_type}} {{cfunc_name}}(PyObject *op1, PyObject *op2, double floatv
} }
{{else}} {{else}}
// copied from floatobject.c in Py3.5: // copied from floatobject.c in Py3.5:
{{if order == 'CObj' and c_op in '%/'}}{{zerodiv_check('b')}}{{endif}}
PyFPE_START_PROTECT("{{op.lower() if not op.endswith('Divide') else 'divide'}}", return NULL) PyFPE_START_PROTECT("{{op.lower() if not op.endswith('Divide') else 'divide'}}", return NULL)
{{if c_op == '%'}} {{if c_op == '%'}}
result = fmod(a, b); result = fmod(a, b);
......
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