Issue #29282: add fused multiply-add function, math.fma.
diff --git a/Modules/clinic/mathmodule.c.h b/Modules/clinic/mathmodule.c.h
index 84a7a70..4e9fe20 100644
--- a/Modules/clinic/mathmodule.c.h
+++ b/Modules/clinic/mathmodule.c.h
@@ -80,6 +80,40 @@
#define MATH_FACTORIAL_METHODDEF \
{"factorial", (PyCFunction)math_factorial, METH_O, math_factorial__doc__},
+PyDoc_STRVAR(math_fma__doc__,
+"fma($module, x, y, z, /)\n"
+"--\n"
+"\n"
+"Fused multiply-add operation. Compute (x * y) + z with a single round.");
+
+#define MATH_FMA_METHODDEF \
+ {"fma", (PyCFunction)math_fma, METH_FASTCALL, math_fma__doc__},
+
+static PyObject *
+math_fma_impl(PyObject *module, double x, double y, double z);
+
+static PyObject *
+math_fma(PyObject *module, PyObject **args, Py_ssize_t nargs, PyObject *kwnames)
+{
+ PyObject *return_value = NULL;
+ double x;
+ double y;
+ double z;
+
+ if (!_PyArg_ParseStack(args, nargs, "ddd:fma",
+ &x, &y, &z)) {
+ goto exit;
+ }
+
+ if (!_PyArg_NoStackKeywords("fma", kwnames)) {
+ goto exit;
+ }
+ return_value = math_fma_impl(module, x, y, z);
+
+exit:
+ return return_value;
+}
+
PyDoc_STRVAR(math_trunc__doc__,
"trunc($module, x, /)\n"
"--\n"
@@ -536,4 +570,4 @@
exit:
return return_value;
}
-/*[clinic end generated code: output=71806f73a5c4bf0b input=a9049054013a1b77]*/
+/*[clinic end generated code: output=f428e1075d00c334 input=a9049054013a1b77]*/
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 8bd38d0..66e88b6 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -1596,6 +1596,47 @@
/*[clinic input]
+math.fma
+
+ x: double
+ y: double
+ z: double
+ /
+
+Fused multiply-add operation. Compute (x * y) + z with a single round.
+[clinic start generated code]*/
+
+static PyObject *
+math_fma_impl(PyObject *module, double x, double y, double z)
+/*[clinic end generated code: output=4fc8626dbc278d17 input=2ae8bb2a6e0f8b77]*/
+{
+ double r;
+ r = fma(x, y, z);
+
+ /* Fast path: if we got a finite result, we're done. */
+ if (Py_IS_FINITE(r)) {
+ return PyFloat_FromDouble(r);
+ }
+
+ /* Non-finite result. Raise an exception if appropriate, else return r. */
+ if (Py_IS_NAN(r)) {
+ if (!Py_IS_NAN(x) && !Py_IS_NAN(y) && !Py_IS_NAN(z)) {
+ /* NaN result from non-NaN inputs. */
+ PyErr_SetString(PyExc_ValueError, "invalid operation in fma");
+ return NULL;
+ }
+ }
+ else if (Py_IS_FINITE(x) && Py_IS_FINITE(y) && Py_IS_FINITE(z)) {
+ /* Infinite result from finite inputs. */
+ PyErr_SetString(PyExc_OverflowError, "overflow in fma");
+ return NULL;
+ }
+
+ return PyFloat_FromDouble(r);
+}
+
+
+/*[clinic input]
math.trunc
x: object
@@ -2224,6 +2265,7 @@
{"fabs", math_fabs, METH_O, math_fabs_doc},
MATH_FACTORIAL_METHODDEF
MATH_FLOOR_METHODDEF
+ MATH_FMA_METHODDEF
MATH_FMOD_METHODDEF
MATH_FREXP_METHODDEF
MATH_FSUM_METHODDEF