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Cleanup of dfflibmap cellmap exploration code

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This commit is contained in:
Clifford Wolf 2013-12-20 14:21:18 +01:00
parent eaf7d9675d
commit 1fb29050e5
1 changed files with 20 additions and 17 deletions
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37
passes/techmap/dfflibmap.cc
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@ -473,23 +473,26 @@ struct DfflibmapPass : public Pass {
find_cell_sr(libparser.ast, "$_DFFSR_PPN_", true, true, false);
find_cell_sr(libparser.ast, "$_DFFSR_PPP_", true, true, true);
int level = 0;
while (level < 3) {
bool did_something = false;
switch (level) {
case 2:
did_something |= expand_cellmap("$_DFF_*_", "C");
did_something |= expand_cellmap("$_DFF_*??_", "C");
did_something |= expand_cellmap("$_DFFSR_*??_", "C");
case 1:
did_something |= expand_cellmap("$_DFF_??*_", "DQ");
case 0:
did_something |= expand_cellmap("$_DFF_?*?_", "R");
did_something |= expand_cellmap("$_DFFSR_?*?_", "S");
did_something |= expand_cellmap("$_DFFSR_??*_", "R");
}
if (!did_something)
level++;
// try to implement as many cells as possible just by inverting
// the SET and RESET pins. If necessary, implement cell types
// by inverting both D and Q. Only invert clock pins if there
// is no other way of implementing the cell.
while (1)
{
if (expand_cellmap("$_DFF_?*?_", "R") ||
expand_cellmap("$_DFFSR_?*?_", "S") ||
expand_cellmap("$_DFFSR_??*_", "R"))
continue;
if (expand_cellmap("$_DFF_??*_", "DQ"))
continue;
if (expand_cellmap("$_DFF_*_", "C") ||
expand_cellmap("$_DFF_*??_", "C") ||
expand_cellmap("$_DFFSR_*??_", "C"))
continue;
break;
}
map_sr_to_arst("$_DFFSR_NNN_", "$_DFF_NN0_");