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-rw-r--r--passes/pmgen/peepopt_dffmux.pmg29
1 files changed, 25 insertions, 4 deletions
diff --git a/passes/pmgen/peepopt_dffmux.pmg b/passes/pmgen/peepopt_dffmux.pmg
index 9b4fef76f..60a708616 100644
--- a/passes/pmgen/peepopt_dffmux.pmg
+++ b/passes/pmgen/peepopt_dffmux.pmg
@@ -1,16 +1,34 @@
pattern dffmux
-state <IdString> cemuxAB
+state <IdString> cemuxAB rstmuxBA
+state <SigSpec> sigD
match dff
select dff->type == $dff
select GetSize(port(dff, \D)) > 1
endmatch
+match rstmux
+ select rstmux->type == $mux
+ select GetSize(port(rstmux, \Y)) > 1
+ index <SigSpec> port(rstmux, \Y) === port(dff, \D)
+ choice <IdString> BA {\B, \A}
+ select port(rstmux, BA).is_fully_const()
+ set rstmuxBA BA
+ optional
+endmatch
+
+code sigD
+ if (rstmux)
+ sigD = port(rstmux, rstmuxBA == \B ? \A : \B);
+ else
+ sigD = port(dff, \D);
+endcode
+
match cemux
select cemux->type == $mux
select GetSize(port(cemux, \Y)) > 1
- index <SigSpec> port(cemux, \Y) === port(dff, \D)
+ index <SigSpec> port(cemux, \Y) === sigD
choice <IdString> AB {\A, \B}
index <SigSpec> port(cemux, AB) === port(dff, \Q)
set cemuxAB AB
@@ -19,6 +37,9 @@ endmatch
code
SigSpec &D = cemux->connections_.at(cemuxAB == \A ? \B : \A);
SigSpec &Q = dff->connections_.at(\Q);
+ Const rst;
+ if (rstmux)
+ rst = port(rstmux, rstmuxBA).as_const();
int width = GetSize(D);
if (D[width-1] == D[width-2]) {
@@ -30,12 +51,12 @@ code
for (i = width-1; i >= 2; i--) {
if (!is_signed) {
module->connect(Q[i], sign);
- if (D[i-1] != sign)
+ if (D[i-1] != sign || (rst.size() && rst[i-1] != rst[width-1]))
break;
}
else {
module->connect(Q[i], Q[i-1]);
- if (D[i-2] != sign)
+ if (D[i-2] != sign || (rst.size() && rst[i-1] != rst[width-1]))
break;
}
}