From 7463f3a409ce838ad2f5080237908c4ba6f88f83 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 1 Sep 2023 22:34:15 -0700
Subject: [PATCH 1/3] Optimise math.ceil for known exact float
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Content-Type: text/plain; charset=UTF-8
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This matches a similar optimisation done for math.floor in
https://github.com/python/cpython/pull/21072

Before:
```
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=3.14' 'ceil(x)'
20000000 loops, best of 11: 13.3 nsec per loop
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=0.0' 'ceil(x)'
20000000 loops, best of 11: 13.3 nsec per loop
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=-3.14E32' 'ceil(x)'
10000000 loops, best of 11: 35.3 nsec per loop
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=-323452345.14' 'ceil(x)'
10000000 loops, best of 11: 21.8 nsec per loop
```

After:
```
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=3.14' 'ceil(x)'
20000000 loops, best of 11: 11.8 nsec per loop
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=0.0' 'ceil(x)'
20000000 loops, best of 11: 11.7 nsec per loop
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=-3.14E32' 'ceil(x)'
10000000 loops, best of 11: 32.7 nsec per loop
λ ./python.exe -m timeit -r 11 -s 'from math import ceil' -s 'x=-323452345.14' 'ceil(x)'
10000000 loops, best of 11: 20.1 nsec per loop
```
---
 Modules/mathmodule.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 2d896e7fe333a4..2f29735df011e7 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -1125,8 +1125,13 @@ static PyObject *
 math_ceil(PyObject *module, PyObject *number)
 /*[clinic end generated code: output=6c3b8a78bc201c67 input=2725352806399cab]*/
 {
+    double x;
 
-    if (!PyFloat_CheckExact(number)) {
+    if (PyFloat_CheckExact(number)) {
+        x = PyFloat_AS_DOUBLE(number);
+    }
+    else
+    {
         math_module_state *state = get_math_module_state(module);
         PyObject *method = _PyObject_LookupSpecial(number, state->str___ceil__);
         if (method != NULL) {
@@ -1136,11 +1141,10 @@ math_ceil(PyObject *module, PyObject *number)
         }
         if (PyErr_Occurred())
             return NULL;
+        x = PyFloat_AsDouble(number);
+        if (x == -1.0 && PyErr_Occurred())
+            return NULL;
     }
-    double x = PyFloat_AsDouble(number);
-    if (x == -1.0 && PyErr_Occurred())
-        return NULL;
-
     return PyLong_FromDouble(ceil(x));
 }
 

From 5c46412e2f18944f035c01ced7656231aa6be6a8 Mon Sep 17 00:00:00 2001
From: hauntsaninja <hauntsaninja@gmail.com>
Date: Fri, 6 Oct 2023 15:27:08 -0700
Subject: [PATCH 2/3] pep 7

---
 Modules/mathmodule.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 2f29735df011e7..a4d94665592351 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -1130,8 +1130,7 @@ math_ceil(PyObject *module, PyObject *number)
     if (PyFloat_CheckExact(number)) {
         x = PyFloat_AS_DOUBLE(number);
     }
-    else
-    {
+    else {
         math_module_state *state = get_math_module_state(module);
         PyObject *method = _PyObject_LookupSpecial(number, state->str___ceil__);
         if (method != NULL) {
@@ -1200,8 +1199,7 @@ math_floor(PyObject *module, PyObject *number)
     if (PyFloat_CheckExact(number)) {
         x = PyFloat_AS_DOUBLE(number);
     }
-    else
-    {
+    else {
         math_module_state *state = get_math_module_state(module);
         PyObject *method = _PyObject_LookupSpecial(number, state->str___floor__);
         if (method != NULL) {

From 6c28b764a947750b522ee0d25540a19f50abc8da Mon Sep 17 00:00:00 2001
From: "blurb-it[bot]" <43283697+blurb-it[bot]@users.noreply.github.com>
Date: Fri, 6 Oct 2023 22:30:29 +0000
Subject: [PATCH 3/3] =?UTF-8?q?=F0=9F=93=9C=F0=9F=A4=96=20Added=20by=20blu?=
 =?UTF-8?q?rb=5Fit.?=
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Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../2023-10-06-22-30-25.gh-issue-110489.rI2n8A.rst               | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 Misc/NEWS.d/next/Core and Builtins/2023-10-06-22-30-25.gh-issue-110489.rI2n8A.rst

diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-10-06-22-30-25.gh-issue-110489.rI2n8A.rst b/Misc/NEWS.d/next/Core and Builtins/2023-10-06-22-30-25.gh-issue-110489.rI2n8A.rst
new file mode 100644
index 00000000000000..6252d00cc583d3
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-10-06-22-30-25.gh-issue-110489.rI2n8A.rst	
@@ -0,0 +1 @@
+Optimise :func:`math.ceil` when the input is exactly a float, resulting in about a 10% improvement.