Author: Antonio Cuni <[email protected]>
Branch: extradoc
Changeset: r5811:853481996a2f
Date: 2017-07-11 12:40 +0200
http://bitbucket.org/pypy/extradoc/changeset/853481996a2f/
Log: more slides
diff --git a/talk/ep2017/the-joy-of-pypy-jit/beamerdefs.txt
b/talk/ep2017/the-joy-of-pypy-jit/beamerdefs.txt
--- a/talk/ep2017/the-joy-of-pypy-jit/beamerdefs.txt
+++ b/talk/ep2017/the-joy-of-pypy-jit/beamerdefs.txt
@@ -28,6 +28,14 @@
}
+.. |tiny| raw:: latex
+
+ {\tiny
+
+.. |end_tiny| raw:: latex
+
+ }
+
.. |strike<| raw:: latex
\sout{
diff --git a/talk/ep2017/the-joy-of-pypy-jit/talk.rst
b/talk/ep2017/the-joy-of-pypy-jit/talk.rst
--- a/talk/ep2017/the-joy-of-pypy-jit/talk.rst
+++ b/talk/ep2017/the-joy-of-pypy-jit/talk.rst
@@ -67,8 +67,10 @@
- etc.
- PRO: readability
-
-- CON: speed?
+
+|pause|
+
+- CON: **cost of abstraction?**
Example: Sobel filter
@@ -86,11 +88,11 @@
- greyscale
-- `w`, `h`
+- ``w, h, data``
-- `array.array('B')` of `w * h` bytes
+- ``data = array.array('B')`` of ``w * h`` bytes
-- pixel `(x, y)` at index `x + w*y`
+- pixel ``(x, y)`` at index ``x + w*y``
Version 0
@@ -322,3 +324,287 @@
* PyPy is ~400x faster
+
+The cost of abstraction
+------------------------
+
+* CPython
+
+ - each version ~2-3x slower than the previous one
+
+ - v3 is ~8.5x slower than v0
+
+* PyPy
+
+ - abstractions (almost) for free
+
+ - v3 is ~20% slower than v0, v1, v2
+
+
+PyPy JIT 101
+-------------
+
+* What is the JIT doing?
+
+* Which code is optimized away?
+
+
+Loops and guards
+-----------------
+
+|tiny|
+|column1|
+
+.. sourcecode:: python
+
+ def compute(n):
+ total = 0
+ i = 0
+ while i < n:
+ total += i
+ i += 1
+ return total
+
+|pause|
+|column2|
+
+.. sourcecode:: python
+
+ cdef loop0(i, n, total):
+ assert isinstance(n, int)
+ while True:
+ assert i < n
+ total = int_add_ovf(total, i)
+ assert not_overflow(total)
+ i = int_add_ovf(i, 1)
+ assert not_overflow(i)
+
+|end_columns|
+|end_tiny|
+
+Bridges (1)
+-----------------
+
+|tiny|
+|column1|
+
+.. sourcecode:: python
+
+ def compute(n):
+ total = 0
+ i = 0
+ while i < n:
+ if i % 2:
+ total += i
+ else:
+ total += (i-5)
+ i += 1
+ return total
+
+|pause|
+|column2|
+
+.. sourcecode:: python
+
+ cdef loop0(i, n, total):
+ assert isinstance(n, int)
+ while True:
+ assert i < n
+ assert i % 2 != 0
+ total = int_add_ovf(total, i)
+ assert not_overflow(total)
+ i = int_add_ovf(i, 1)
+ assert not_overflow(i)
+
+|end_columns|
+|end_tiny|
+
+Bridges (2)
+-----------------
+
+|tiny|
+|column1|
+
+.. sourcecode:: python
+
+ def compute(n):
+ total = 0
+ i = 0
+ while i < n:
+ if i % 2:
+ total += i
+ else:
+ total += (i-5)
+ i += 1
+ return total
+
+|column2|
+
+.. sourcecode:: python
+
+ cdef loop0(i, n, total):
+ assert isinstance(n, int)
+ while True:
+ assert i < n
+ if i % 2 != 0:
+ total = int_add_ovf(total, i)
+ assert not_overflow(total)
+ i = int_add_ovf(i, 1)
+ assert not_overflow(i)
+ else:
+ tmp = int_sub_ovf(i, 5)
+ assert not_overflow(tmp)
+ total = int_add_ovf(total, tmp)
+ i = int_add_ovf(i, 1)
+ assert not_overflow(i)
+
+|end_columns|
+|end_tiny|
+
+
+Inlining
+-----------------
+
+|tiny|
+|column1|
+
+.. sourcecode:: python
+
+ def fn(a, b):
+ return a + b
+
+ def compute(n):
+ total = 0
+ i = 0
+ while i < n:
+ total = fn(total, i)
+ i += 1
+ return total
+
+|column2|
+
+.. sourcecode:: python
+
+ assert version(globals()) == 42
+ assert id(fn.__code__) == 0x1234
+ #
+ assert isinstance(n, int)
+ while True:
+ assert i < n
+ total = int_add_ovf(total, i) # inlined!
+ assert not_overflow(total)
+ i = int_add_ovf(i, 1)
+ assert not_overflow(i)
+
+|end_columns|
+|end_tiny|
+
+
+Classes
+-----------------
+
+|tiny|
+|column1|
+
+.. sourcecode:: python
+
+ import math
+ class Point(object):
+ def __init__(self, x, y):
+ self.x = x
+ self.y = y
+
+ def distance(self):
+ return math.hypot(self.x, self.y)
+
+ def compute(points):
+ total = 0
+ for p in points:
+ total += p.distance()
+ return total
+
+|column2|
+
+.. sourcecode:: python
+
+ cdef loop0(total, list_iter):
+ assert version(globals()) == 42
+ assert version(math.__dict__) == 23
+ assert version(Point.__dict__) == 56
+ assert id(Point.distance.__globals__) == 0x1234
+ assert version(Point.distance.__globals__) == 78
+ assert id(Point.distance.__code__) == 0x5678
+
+ while True:
+ p = next(list_iter)
+ assert isinstance(p, Point)
+ # <inlined Point.distance>
+ assert isinstance(p.x, float)
+ assert isinstance(p.y, float)
+ p_x = p.x
+ p_y = p.y
+ tmp = c_call(math.hypot, p_x, p_y)
+ # </inlined>
+ total = float_add(total, tmp)
+
+|end_columns|
+|end_tiny|
+
+
+Virtuals
+-----------------
+
+|tiny|
+|column1|
+
+.. sourcecode:: python
+
+ def compute(n):
+ total = 0.0
+ i = 0.0
+ while i < n:
+ p = Point(i, i+1)
+ total += p.distance()
+ i += 1
+ return total
+
+|pause|
+|column2|
+
+.. sourcecode:: python
+
+ assert ...
+ assert isinstance(n, int)
+ assert isinstance(i, float)
+ while True:
+ assert i < n
+ # Point() is "virtualized" into p_x and p_y
+ p_x = i
+ p_y = float_add(i, 1.0)
+ #
+ # inlined call to Point.hypot
+ tmp = c_call(math.hypot, p_x, p_y)
+ total = float_add(total, tmp)
+
+|end_columns|
+|end_tiny|
+
+
+
+More PyPy at EuroPython
+------------------------
+
+* PyPy Help Desk
+
+ - Tomorrow, 10:30-12:00 and 14:00-15:30
+
+ - Come and ask us questions!
+
+* "PyPy meets Python 3 and numpy"
+
+ - Armin Rigo
+
+ - Friday, 14:00
+
+* Or, just talk to us :)
+
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