Changes in doc/theses/andrew_beach_MMath/performance.tex [5438e41:0b67a19]

File:

• doc/theses/andrew_beach_MMath/performance.tex (modified) (4 diffs)

doc/theses/andrew_beach_MMath/performance.tex

@@ -160 +160 @@
 % Match All     &   3719462155 &   43294042 &   3223004977 &  1286054154 &   623887874 \\
 % Match None    &   4971630929 &   55311709 &   9481225467 &  1310251289 &   623752624 \\
-%
-% run-algol-04-a
-% --------------
-% Raise Empty   & 0.0 & 0.0 &  3250260945 & 0.0 & 0.0 \\
-% Raise D'tor   & 0.0 & 0.0 & 29017675113 & N/A & N/A \\
-% Raise Finally & 0.0 & 0.0 &         N/A & 0.0 & 0.0 \\
-% Raise Other   & 0.0 & 0.0 & 24411823773 & 0.0 & 0.0 \\
-% Cross Handler & 0.0 & 0.0 &      769334 & 0.0 & 0.0 \\
-% Cross Finally & 0.0 & N/A &         N/A & 0.0 & 0.0 \\
-% Match All     & 0.0 & 0.0 &  3254283504 & 0.0 & 0.0 \\
-% Match None    & 0.0 & 0.0 &  9476060146 & 0.0 & 0.0 \\
-
 \begin{tabular}{|l|c c c c c|}
 \hline
@@ -208 +196 @@
 % Match All     &   3189512499 &   39124453 &   2667795989 &  1525889031 &   733785613 \\
 % Match None    &   4094675477 &   48749857 &   7850618572 &  1566713577 &   733478963 \\
-%
-% run-plg7a-04-a
-% --------------
-% 0.0 are unfilled.
-% Raise Empty   & 0.0 & 0.0 &  2770781479 & 0.0 & 0.0 \\
-% Raise D'tor   & 0.0 & 0.0 & 23530084907 & N/A & N/A \\
-% Raise Finally & 0.0 & 0.0 &         N/A & 0.0 & 0.0 \\
-% Raise Other   & 0.0 & 0.0 & 23816827982 & 0.0 & 0.0 \\
-% Cross Handler & 0.0 & 0.0 &     1422188 & 0.0 & 0.0 \\
-% Cross Finally & 0.0 & N/A &         N/A & 0.0 & 0.0 \\
-% Match All     & 0.0 & 0.0 &  2671989778 & 0.0 & 0.0 \\
-% Match None    & 0.0 & 0.0 &  7829059869 & 0.0 & 0.0 \\
 
 % PLG7A (in seconds)
@@ -226 +202 @@
               & \CFA (Terminate) & \CFA (Resume) & \Cpp & Java & Python \\
 \hline
+% Raise Empty   & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 \\
+% Raise D'tor   & 0.0 & 0.0 & 0.0 & N/A & N/A \\
+% Raise Finally & 0.0 & 0.0 & N/A & 0.0 & 0.0 \\
+% Raise Other   & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 \\
+% Cross Handler & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 \\
+% Cross Finally & 0.0 & N/A & N/A & 0.0 & 0.0 \\
+% Match All     & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 \\
+% Match None    & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 \\
 Raise Empty   & 0.0 & 0.0 & 0.0 & 0.0 & 0.0 \\
 Raise D'tor   & 0.0 & 0.0 & 0.0 & N/A & N/A \\
@@ -247 +231 @@
 
 This means that while \CFA does not actually keep up with Python in every
-case it is usually no worse than roughly half the speed of \Cpp. This is good
+case it is no worse than roughly half the speed of \Cpp. This is good
 enough for the prototyping purposes of the project.
 
-The test case where \CFA falls short is Raise Other, the case where the
-stack is unwound including a bunch of non-matching handlers.
-This slowdown seems to come from missing optimizations,
-the results above came from gcc/g++ 10 (gcc as \CFA backend or g++ for \Cpp)
-but the results change if they are run in gcc/g++ 9 instead.
-Importantly, there is a huge slowdown in \Cpp's results bringing that brings
-\CFA's performace back in that roughly half speed area. However many other
-\CFA benchmarks increase their run-time by a similar amount falling far
-behind their \Cpp counter-parts.
-
-This suggests that the performance issue in Raise Other is just an
-optimization not being applied. Later versions of gcc may be able to
-optimize this case further, at least down to the half of \Cpp mark.
-A \CFA compiler that directly produced assembly could do even better as it
-would not have to work across some of \CFA's current abstractions, like
-the try terminate function.
+One difference not shown is that optimizations in \CFA is very fragile.
+The \CFA compiler uses gcc as part of its complation process and the version
+of gcc could change the speed of some of the benchmarks by 10 times or more.
+Similar changes to g++ for the \Cpp benchmarks had no significant changes.
+Because of the connection between gcc and g++; this suggests it is not the
+optimizations that are changing but how the optimizer is detecting if the
+optimizations can be applied. So the optimizations are always applied in
+g++, but only newer versions of gcc can detect that they can be applied in
+the more complex \CFA code.
 
 Resumption exception handling is also incredibly fast. Often an order of