Commit 3126e49b authored by Alexandre Duret-Lutz's avatar Alexandre Duret-Lutz
Browse files

* src/misc/minato.hh (minato_isop(bdd,bdd)): New constructor variant.

(minato_isop::local_vars::vars): New attribute.
(minato_isop::local_vars::local_vars): Add the vars arguments.
(minato_isop::todo, minato_isop::cube, minato_isop::ret): Rename as ...
(minato_isop::todo_, minato_isop::cube_, minato_isop::ret_): ... these.
* src/misc/minato.cc: Adjust to factorize only variables in vars.
parent e6c113f9
2003-11-24 Alexandre Duret-Lutz <adl@src.lip6.fr>
* src/misc/minato.hh (minato_isop(bdd,bdd)): New constructor variant.
(minato_isop::local_vars::vars): New attribute.
(minato_isop::local_vars::local_vars): Add the vars arguments.
(minato_isop::todo, minato_isop::cube, minato_isop::ret): Rename as ...
(minato_isop::todo_, minato_isop::cube_, minato_isop::ret_): ... these.
* src/misc/minato.cc: Adjust to factorize only variables in vars.
* m4/devel.m4: Fix quoting and simplify default setting of
enable_devel.
......
......@@ -27,55 +27,80 @@ namespace spot
{
minato_isop::minato_isop(bdd input)
: ret(bddfalse)
: ret_(bddfalse)
{
todo.push(local_vars(input, input));
cube.push(bddtrue);
todo_.push(local_vars(input, input, bdd_support(input)));
cube_.push(bddtrue);
}
minato_isop::minato_isop(bdd input, bdd vars)
: ret_(bddfalse)
{
todo_.push(local_vars(input, input, vars));
cube_.push(bddtrue);
}
bdd
minato_isop::next()
{
while (todo.size())
while (todo_.size())
{
local_vars& l = todo.top();
local_vars& l = todo_.top();
switch (l.step)
{
case local_vars::FirstStep:
if (l.f_min == bddfalse)
{
ret = bddfalse;
todo.pop();
continue;
}
if (l.f_max == bddtrue)
{
ret = bddtrue;
todo.pop();
return cube.top();
}
l.step = local_vars::SecondStep;
next_var:
{
// Pick the topmost variable.
if (l.f_min == bddfalse)
{
ret_ = bddfalse;
todo_.pop();
continue;
}
if (l.vars == bddtrue || l.f_max == bddtrue)
{
ret_ = l.f_max;
todo_.pop();
return cube_.top() & ret_;
}
assert(l.vars != bddfalse);
// Pick the first variable in VARS that is used by F_MIN
// or F_MAX. We know that VARS, F_MIN or F_MAX are not
// constants (bddtrue or bddfalse) because one of the
// two above `if' would have matched; so it's ok to call
// bdd_var().
int v = bdd_var(l.vars);
l.vars = bdd_high(l.vars);
int v_min = bdd_var(l.f_min);
int v_max = bdd_var(l.f_max);
int v = std::min(v_min, v_max);
if (v < v_min && v < v_max)
// Do not use a while() for this goto, because we want
// `continue' to be relative to the outermost while().
goto next_var;
l.step = local_vars::SecondStep;
// The following two `if's do
// v0 = bdd_nithvar(v);
// v1 = bdd_ithvar(v);
bdd v0 = bdd_nithvar(v);
l.v1 = bdd_ithvar(v);
// All the following should be equivalent to
// f0_min = bdd_restrict(f_min, v0);
// f0_max = bdd_restrict(f_max, v0);
// f1_min = bdd_restrict(f_min, v1);
// f1_max = bdd_restrict(f_max, v1);
// but since we now the v is the topmost variable,
// its more efficient to use bdd_low and bdd_high.
// but we try to avoid bdd_restrict when possible.
if (v == v_min)
{
l.f0_min = bdd_low(l.f_min);
l.f1_min = bdd_high(l.f_min);
}
else if (v_min < v)
{
l.f0_min = bdd_restrict(l.f_min, v0);
l.f1_min = bdd_restrict(l.f_min, l.v1);
}
else
{
l.f1_min = l.f0_min = l.f_min;
......@@ -85,41 +110,45 @@ namespace spot
l.f0_max = bdd_low(l.f_max);
l.f1_max = bdd_high(l.f_max);
}
else if (v_max < v)
{
l.f0_max = bdd_restrict(l.f_max, v0);
l.f1_max = bdd_restrict(l.f_max, l.v1);
}
else
{
l.f1_max = l.f0_max = l.f_max;
}
l.v1 = bdd_ithvar(v);
cube.push(cube.top() & bdd_nithvar(v));
todo.push(local_vars(l.f0_min - l.f1_max, l.f0_max));
cube_.push(cube_.top() & v0);
todo_.push(local_vars(l.f0_min - l.f1_max, l.f0_max, l.vars));
}
continue;
case local_vars::SecondStep:
l.step = local_vars::ThirdStep;
l.g0 = ret;
cube.pop();
cube.push(cube.top() & l.v1);
todo.push(local_vars(l.f1_min - l.f0_max, l.f1_max));
l.g0 = ret_;
cube_.pop();
cube_.push(cube_.top() & l.v1);
todo_.push(local_vars(l.f1_min - l.f0_max, l.f1_max, l.vars));
continue;
case local_vars::ThirdStep:
l.step = local_vars::FourthStep;
l.g1 = ret;
cube.pop();
l.g1 = ret_;
cube_.pop();
{
bdd f0s_min = l.f0_min - l.g0;
bdd f1s_min = l.f1_min - l.g1;
bdd fs_max = l.f0_max & l.f1_max;
bdd fs_min = fs_max & (f0s_min | f1s_min);
todo.push(local_vars(fs_min, fs_max));
todo_.push(local_vars(fs_min, fs_max, l.vars));
}
continue;
case local_vars::FourthStep:
ret |= (l.g0 - l.v1) | (l.g1 & l.v1);
todo.pop();
ret_ |= (l.g0 - l.v1) | (l.g1 & l.v1);
todo_.pop();
continue;
}
// Unreachable code.
......
......@@ -52,6 +52,10 @@ namespace spot
/// \brief Conctructor.
/// \arg input The BDD function to translate in ISOP.
minato_isop(bdd input);
/// \brief Conctructor.
/// \arg input The BDD function to translate in ISOP.
/// \arg vars The set of BDD variables to factorize in \a input.
minato_isop(bdd input, bdd vars);
/// \brief Compute the next sum term of the ISOP form.
/// Return \c bddfalse when all terms have been output.
bdd next();
......@@ -70,16 +74,19 @@ namespace spot
// we had to split it in four step (each step is separated
// from the other by a call to ISOP in the original algorithm).
enum { FirstStep, SecondStep, ThirdStep, FourthStep } step;
// The list of variable to factorize. This is an addition to
// the original algorithm.
bdd vars;
bdd v1;
bdd f0_min, f0_max;
bdd f1_min, f1_max;
bdd g0, g1;
local_vars(bdd f_min, bdd f_max)
: f_min(f_min), f_max(f_max), step(FirstStep) {}
local_vars(bdd f_min, bdd f_max, bdd vars)
: f_min(f_min), f_max(f_max), step(FirstStep), vars(vars) {}
};
std::stack<local_vars> todo;
std::stack<bdd> cube;
bdd ret;
std::stack<local_vars> todo_;
std::stack<bdd> cube_;
bdd ret_;
};
}
......
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