From: Clifford Wolf <clifford@clifford.at>
Date: Tue, 30 Apr 2019 05:59:39 +0000 (+0200)
Subject: Progress in shiftmul peepopt pattern
X-Git-Tag: yosys-0.9~155^2~6
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=58238da133fd236642f352c06f4056832b52d21c;p=yosys.git

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 0a56016b2..d9d5757ca 100644
--- 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