Progress in shiftmul peepopt pattern

Signed-off-by: Clifford Wolf <clifford@clifford.at>

diff --git a/passes/pmgen/peepopt.pmg b/passes/pmgen/peepopt.pmg
index 0a56016b271a613dcbf4b594ad9843768b5de1e5..d9d5757ca7c2d52644da355ee116399bd212aa2c 100644 (file)
--- a/passes/pmgen/peepopt.pmg
+++ b/passes/pmgen/peepopt.pmg
@@ -13,9 +13,11 @@ code shamt
                        shamt.remove(GetSize(shamt)-1);
                } while (shamt[GetSize(shamt)-1] == State::S0);
        } else
-       if (param(shift, \B_SIGNED).as_bool()) {
+       if (shift->type.in($shift, $shiftx) && param(shift, \B_SIGNED).as_bool()) {
                reject;
        }
+       if (GetSize(shamt) > 20)
+               reject;
 endcode
 
 match mul
@@ -26,9 +28,55 @@ endmatch
 
 code
        IdString const_factor_port = port(mul, \A).is_fully_const() ? \A : \B;
-       int const_factor = port(mul, const_factor_port).as_int();
+       IdString const_factor_signed = const_factor_port == \A ? \A_SIGNED : \B_SIGNED;
+       Const const_factor_cnst = port(mul, const_factor_port).as_const();
+       int const_factor = const_factor_cnst.as_int();
+
+       if (GetSize(const_factor_cnst) == 0)
+               reject;
+
+       if (const_factor_cnst.bits[GetSize(const_factor_cnst)-1] != State::S0 &&
+                       param(mul, const_factor_signed).as_bool())
+               reject;
+
+       if (GetSize(const_factor_cnst) > 20)
+               reject;
+
        if (GetSize(port(shift, \Y)) > const_factor)
                reject;
-       log_dump(shift, shamt, mul, const_factor);
+
+       log("shiftmul pattern in %s: shift=%s, mul=%s\n", log_id(module), log_id(shift), log_id(mul));
+
+       int new_const_factor_log2 = ceil_log2(const_factor);
+       int new_const_factor = 1 << new_const_factor_log2;
+
+       SigSpec padding(State::Sx, new_const_factor-const_factor);
+       SigSpec old_a = port(shift, \A), new_a;
+       int trunc = 0;
+
+       if (GetSize(old_a) % const_factor != 0) {
+               trunc = const_factor - GetSize(old_a) % const_factor;
+               old_a.append(SigSpec(State::Sx, trunc));
+       }
+
+       for (int i = 0; i*const_factor < GetSize(old_a); i++) {
+               SigSpec slice = old_a.extract(i*const_factor, const_factor);
+               new_a.append(slice);
+               new_a.append(padding);
+       }
+
+       if (trunc > 0)
+               new_a.remove(GetSize(new_a)-trunc, trunc);
+
+       SigSpec new_b = {port(mul, const_factor_port == \A ? \B : \A), SigSpec(State::S0, new_const_factor_log2)};
+       if (param(shift, \B_SIGNED).as_bool())
+               new_b.append(State::S0);
+
+       shift->setPort(\A, new_a);
+       shift->setParam(\A_WIDTH, GetSize(new_a));
+       shift->setPort(\B, new_b);
+       shift->setParam(\B_WIDTH, GetSize(new_b));
+
+       blacklist(shift);
        reject;
 endcode