Commit 620544cc authored by Taddeus Kroes's avatar Taddeus Kroes

Merge branch 'master' of github.com:taddeus/peephole

parents 2aac7d87 9525cbe1
......@@ -116,7 +116,7 @@ We now add the instruction above the first use, and write the result in a new
variable. Then all occurrences of this expression can be replaced by a move of
from new variable into the original destination variable of the instruction.
This is a less efficient method then the DAG, but because the basic blocks are
This is a less efficient method then the dag, but because the basic blocks are
in general not very large and the execution time of the optimizer is not a
primary concern, this is not a big problem.
......@@ -216,7 +216,7 @@ The optimizations are done in two different steps. First the global
optimizations are performed, which are only the optimizations on branch-jump
constructions. This is done repeatedly until there are no more changes.
After all possible global optimizations are done, the program is separated into
After all possible global optimizations are done, the program is seperated into
basic blocks. The algorithm to do this is described earlier, and means all
jump and branch instructions are called leaders, as are their targets. A basic
block then goes from leader to leader.
......@@ -236,57 +236,17 @@ concatenated again into a list. After this is done, the list is passed on to
the writer, which writes the instructions back to Assembly and saves the file
so we can let xgcc compile it.
\section{Testing}
Of course, it has to be guaranteed that the optimized code still functions
exactly the same as the none-optimized code. To do this, testing is an
important part of out program. We have two stages of testing. The first stage
is unit testing. The second stage is to test whether the compiled code has
exactly the same output.
\subsection{Unit testing}
For almost every piece of important code, unit tests are available. Unit tests
give the possibility to check whether each small part of the program, for
instance each small function, is performing as expected. This way bugs are
found early and very exactly. Otherwise, one would only see that there is a
mistake in the program, not knowing where this bug is. Naturally, this means
debugging is a lot easier.
The unit tests can be run by executing \texttt{make test} in the root folder of
the project. This does require the \texttt{textrunner} module.
\section{Results}
Also available is a coverage report. This report shows how much of the code has
been unit tested. To make this report, the command \texttt{make coverage} can
be run in the root folder. The report is than added as a folder \emph{coverage}
in which a \emph{index.html} can be used to see the entire report.
\subsection{pi.c}
\subsection{Ouput comparison}
\subsection{acron.c}
In order to check whether the optimization does not change the functioning of
the program, the output of the provided benchmark programs has to be compared
to the output after optimization. If any of these outputs is not equal to the
original output, our optimizations are to aggressive, or there is a bug
somewhere in the code.
\subsection{whet.c}
\section{Results}
\subsection{slalom.c}
The following results have been obtained:\\
\begin{tabular}{|c|c|c|c|c|c|}
\hline
Benchmark & Original & Optimized & Original & Optimized & Performance \\
& Instructions & instructions & cycles & cycles & boost(cycles)\\
\hline
pi & 134 & & 13011 & & \\
acron & & & 4435687 & & \\
dhrystone & & & 2887710 & & \\
whet & & & 2864089 & & \\
slalom & & & 27270 & & \\
clinpack & & & 1547941 & & \\
\hline
\end{tabular}\\
\\
The imput for slalom was 1000 seconds and a minimum of $n = 100$
\subsection{clinpack.c}
\section{Conclusion}
......
......@@ -141,7 +141,7 @@ def fold_constants(block):
if s.name == 'li':
# Save value in register
if not isinstance(s[1], int):
if not isinstance(s[1], int): # Negative numbers are stored as int
register[s[0]] = int(s[1], 16)
else:
register[s[0]] = s[1]
......@@ -175,6 +175,7 @@ def fold_constants(block):
known.append((s[0], register[s[0]]))
elif s.name == 'mult' and s[0]in register and s[1] in register:
# Multiplication/division with constants
print s
rs, rt = s
a, b = register[rs], register[rt]
......
......@@ -154,7 +154,7 @@ class Statement:
def get_def(self):
"""Get the variable that this statement defines, if any."""
instr = ['move', 'addu', 'subu', 'li', 'dmfc1', 'mov.d']
instr = ['div', 'move', 'addu', 'subu', 'li', 'dmfc1', 'mov.d']
if self.is_command('mtc1'):
return [self[1]]
......@@ -178,7 +178,7 @@ class Statement:
if (self.is_branch() \
and not self.is_command(*['bc1f', 'bc1t', 'bct', 'bcf'])) \
or self.is_store() or self.is_compare() \
or self.is_command(*['mult', 'div', 'dsz', 'mtc1']):
or self.is_command(*['mult', 'dsz', 'mtc1']):
if self.name == 'dsz':
m = re.match('^[^(]+\(([^)]+)\)$', self[0])
......@@ -206,7 +206,7 @@ class Statement:
# Case arg2
if self.is_double_arithmetic() or self.is_set_if_less() \
or self.is_logical() or self.is_truncate() \
or self.is_command(*['addu', 'subu']):
or self.is_command(*['addu', 'subu', 'div']):
if not isinstance(self[2], int):
use.append(self[2])
......
......@@ -99,8 +99,9 @@ class TestStatement(unittest.TestCase):
a = ['a']
self.assertEqual(S('command', 'move', 'a', 'b').get_def(), a)
self.assertEqual(S('command', 'subu', 'a', 'b').get_def(), a)
self.assertEqual(S('command', 'subu', 'a', 'b', 'c').get_def(), a)
self.assertEqual(S('command', 'addu', 'a', 'b', 'c').get_def(), a)
self.assertEqual(S('command', 'div', 'a', 'b', 'c').get_def(), a)
self.assertEqual(S('command', 'sll', 'a', 'b', 'c').get_def(), a)
self.assertEqual(S('command', 'srl', 'a', 'b', 'c').get_def(), a)
self.assertEqual(S('command', 'la', 'a', '16($fp)').get_def(), a)
......@@ -130,7 +131,7 @@ class TestStatement(unittest.TestCase):
self.assertEqual(S('command', 'subu', '$3', '$1', '$2').get_use(), \
arg2)
self.assertEqual(S('command', 'mult', '$1', '$2').get_use(), arg2)
self.assertEqual(S('command', 'div', '$1', '$2').get_use(), arg2)
self.assertEqual(S('command', 'div', '$3', '$1', '$2').get_use(), arg2)
self.assertEqual(S('command', 'move', '$2', '$1').get_use(), arg1)
self.assertEqual(S('command', 'beq', '$1', '$2', '$L1').get_use(), \
arg2)
......
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