From 3f7d1bd6a30ffdc42366b4669606618b91835f80 Mon Sep 17 00:00:00 2001
From: sebastien <sebastien@ac1d8469-bf42-47a9-8791-bf33cf982152>
Date: Tue, 28 Apr 2009 16:04:29 +0000
Subject: [PATCH] trunk preprocessor: added two more symbolic simplication
rules, particularly useful for the static model * x-x=0 * x/x=1
git-svn-id: https://www.dynare.org/svn/dynare/trunk@2640 ac1d8469-bf42-47a9-8791-bf33cf982152
---
DataTree.cc | 36 ++++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 14 deletions(-)
diff --git a/DataTree.cc b/DataTree.cc
index aa44d82b..d7469dff 100644
--- a/DataTree.cc
+++ b/DataTree.cc
@@ -112,14 +112,16 @@ DataTree::AddPlus(NodeID iArg1, NodeID iArg2)
NodeID
DataTree::AddMinus(NodeID iArg1, NodeID iArg2)
{
- if (iArg1 != Zero && iArg2 != Zero)
- return AddBinaryOp(iArg1, oMinus, iArg2);
- else if (iArg1 != Zero)
+ if (iArg2 == Zero)
return iArg1;
- else if (iArg2 != Zero)
+
+ if (iArg1 == Zero)
return AddUMinus(iArg2);
- else
+
+ if (iArg1 == iArg2)
return Zero;
+
+ return AddBinaryOp(iArg1, oMinus, iArg2);
}
NodeID
@@ -170,17 +172,23 @@ DataTree::AddTimes(NodeID iArg1, NodeID iArg2)
NodeID
DataTree::AddDivide(NodeID iArg1, NodeID iArg2)
{
- if (iArg1 != Zero && iArg2 != Zero && iArg2 != One)
- return AddBinaryOp(iArg1, oDivide, iArg2);
- else if (iArg2 == One)
+ if (iArg2 == One)
return iArg1;
- else if (iArg1 == Zero && iArg2 != Zero)
- return Zero;
- else
+
+ // This test should be before the next two, otherwise 0/0 won't be rejected
+ if (iArg2 == Zero)
{
- cerr << "Division by zero!" << endl;
+ cerr << "ERROR: Division by zero!" << endl;
exit(EXIT_FAILURE);
}
+
+ if (iArg1 == Zero)
+ return Zero;
+
+ if (iArg1 == iArg2)
+ return One;
+
+ return AddBinaryOp(iArg1, oDivide, iArg2);
}
NodeID
@@ -250,7 +258,7 @@ DataTree::AddLog(NodeID iArg1)
return Zero;
else
{
- cerr << "log(0) isn't available" << endl;
+ cerr << "ERROR: log(0) not defined!" << endl;
exit(EXIT_FAILURE);
}
}
@@ -263,7 +271,7 @@ NodeID DataTree::AddLog10(NodeID iArg1)
return Zero;
else
{
- cerr << "log10(0) isn't available" << endl;
+ cerr << "ERROR: log10(0) not defined!" << endl;
exit(EXIT_FAILURE);
}
}
--
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