Simplify logic on static designs (#1775)

* command line cycle limit parse

* clippy

* better static guard simplification

* rewrite test

* small change

* small change

* rewrite test

* default to none

calyx-opt/src/passes/simplify_static_guards.rs

@@ -35,11 +35,6 @@ impl SimplifyStaticGuards {
         cur_anded_intervals: &mut Vec<(u64, u64)>,
     ) -> Option<ir::Guard<ir::StaticTiming>> {
         match g {
-            ir::Guard::Not(_)
-            | ir::Guard::Or(_, _)
-            | ir::Guard::True
-            | ir::Guard::CompOp(_, _, _)
-            | ir::Guard::Port(_) => Some(g),
             ir::Guard::And(g1, g2) => {
                 // recursively call separate_anded_intervals on g1 and g2
                 let rest_g1 =
@@ -65,6 +60,11 @@ impl SimplifyStaticGuards {
                 cur_anded_intervals.push(static_timing_info.get_interval());
                 None
             }
+            ir::Guard::True
+            | ir::Guard::CompOp(_, _, _)
+            | ir::Guard::Not(_)
+            | ir::Guard::Or(_, _)
+            | ir::Guard::Port(_) => Some(g),
         }
     }
 
@@ -75,7 +75,7 @@ impl SimplifyStaticGuards {
     /// For example: (port.out | !port1.out) & (port2.out == port3.out) & %[2:8] & %[5:10] ?
     /// becomes (port.out | !port1.out) & (port2.out == port3.out) & %[5:8] ?
     /// by "combining: %[2:8] & %[5:10]
-    fn simplify_guard(
+    fn simplify_anded_guards(
         guard: ir::Guard<ir::StaticTiming>,
         group_latency: u64,
     ) -> ir::Guard<ir::StaticTiming> {
@@ -121,6 +121,30 @@ impl SimplifyStaticGuards {
             (Some(rg), Some(ig)) => ir::Guard::And(Box::new(rg), Box::new(ig)),
         }
     }
+
+    fn simplify_guard(
+        guard: ir::Guard<ir::StaticTiming>,
+        group_latency: u64,
+    ) -> ir::Guard<ir::StaticTiming> {
+        match guard {
+            ir::Guard::Not(g) => ir::Guard::Not(Box::new(
+                Self::simplify_guard(*g, group_latency),
+            )),
+            ir::Guard::Or(g1, g2) => ir::Guard::Or(
+                Box::new(Self::simplify_guard(*g1, group_latency)),
+                Box::new(Self::simplify_guard(*g2, group_latency)),
+            ),
+            ir::Guard::And(_, _) => {
+                Self::simplify_anded_guards(guard, group_latency)
+            }
+            ir::Guard::Info(_) => {
+                Self::simplify_anded_guards(guard, group_latency)
+            }
+            ir::Guard::Port(_)
+            | ir::Guard::True
+            | ir::Guard::CompOp(_, _, _) => guard,
+        }
+    }
 }
 
 impl Visitor for SimplifyStaticGuards {

calyx-opt/src/passes/static_promotion.rs

@@ -143,7 +143,7 @@ pub struct StaticPromotion {
     /// Threshold for promotion
     threshold: u64,
     /// Whether we should stop promoting when we see a loop.
-    stop_loop: bool,
+    cycle_limit: Option<u64>,
 }
 
 // Override constructor to build latency_data information from the primitives
@@ -177,13 +177,13 @@ impl ConstructVisitor for StaticPromotion {
             }
             latency_data.insert(prim.name, GoDone::new(go_ports));
         }
-        let (threshold, stop_loop) = Self::get_threshold(ctx);
+        let (threshold, cycle_limit) = Self::get_threshold(ctx);
         Ok(StaticPromotion {
             latency_data,
             static_group_name: HashMap::new(),
             static_component_latencies: HashMap::new(),
             threshold,
-            stop_loop,
+            cycle_limit,
         })
     }
 
@@ -206,7 +206,7 @@ impl Named for StaticPromotion {
 impl StaticPromotion {
     // Looks through ctx to get the given command line threshold.
     // Default threshold = 1
-    fn get_threshold(ctx: &ir::Context) -> (u64, bool)
+    fn get_threshold(ctx: &ir::Context) -> (u64, Option<u64>)
     where
         Self: Named,
     {
@@ -226,13 +226,24 @@ impl StaticPromotion {
             })
             .collect();
 
-        let mut stop_loop = false;
-        given_opts.iter().for_each(|arg| {
-            if *arg == "stop_loop" {
-                stop_loop = true
+        // searching for "-x static-promotion:cycle-limit=200" and getting back "200"
+        let cycle_limit_str: Option<&str> = given_opts.iter().find_map(|arg| {
+            let split: Vec<&str> = arg.split('=').collect();
+            if let Some(str) = split.first() {
+                if str == &"cycle-limit" {
+                    return Some(split[1]);
+                }
             }
+            None
         });
 
+        // Default to None. There may be a more idiomatic way to do this.
+        let cycle_limit = match cycle_limit_str.unwrap_or("None").parse::<u64>()
+        {
+            Ok(n) => Some(n),
+            Err(_) => None,
+        };
+
         // searching for "-x static-promotion:threshold=1" and getting back "1"
         let threshold: Option<&str> = given_opts.iter().find_map(|arg| {
             let split: Vec<&str> = arg.split('=').collect();
@@ -246,9 +257,10 @@ impl StaticPromotion {
 
         // Need to convert string argument into int argument
         // Always default to threshold=1
+        // Default cycle limit = 2^25 = 33554432
         (
             threshold.unwrap_or("1").parse::<u64>().unwrap_or(1),
-            stop_loop,
+            cycle_limit,
         )
     }
 
@@ -502,6 +514,13 @@ impl StaticPromotion {
         c.is_static() || c.has_attribute(ir::NumAttr::PromoteStatic)
     }
 
+    fn within_cycle_limit(&self, latency: u64) -> bool {
+        if self.cycle_limit.is_none() {
+            return true;
+        }
+        latency < self.cycle_limit.unwrap()
+    }
+
     /// If we've already constructed the static group then use the already existing
     /// group. Otherwise construct `static group` and then return that.
     fn construct_static_group(
@@ -743,18 +762,23 @@ impl StaticPromotion {
         v.iter().map(Self::approx_size).sum()
     }
 
-    /// First checks if the vec of control statements meets the self.threshold.
+    /// First checks if the vec of control statements satsifies the threshold
+    /// and cycle count threshold
     /// (That is, whether the combined approx_size of the static_vec is greater)
-    /// Than the threshold.
+    /// than the threshold and cycle count is less than cycle limit).
     /// If so, converts vec of control to a static seq, and returns a vec containing
     /// the static seq.
     /// Otherwise, just returns the vec without changing it.
-    fn convert_vec_seq_if_threshold(
+    fn convert_vec_seq_if_sat(
         &mut self,
         builder: &mut ir::Builder,
         control_vec: Vec<ir::Control>,
     ) -> Vec<ir::Control> {
-        if Self::approx_control_vec_size(&control_vec) <= self.threshold {
+        if Self::approx_control_vec_size(&control_vec) <= self.threshold
+            || !self.within_cycle_limit(
+                control_vec.iter().map(Self::get_inferred_latency).sum(),
+            )
+        {
             // Return unchanged vec
             return control_vec;
         }
@@ -768,16 +792,25 @@ impl StaticPromotion {
         vec![sseq]
     }
 
-    /// First checks if the vec of control statements meets the self.threshold.
+    /// First checks if the vec of control statements meets the self.threshold
+    /// and is within self.cycle_limit
     /// If so, converts vec of control to a static par, and returns a vec containing
     /// the static par.
     /// Otherwise, just returns the vec without changing it.
-    fn convert_vec_par_if_threshold(
+    fn convert_vec_par_if_sat(
         &mut self,
         builder: &mut ir::Builder,
         control_vec: Vec<ir::Control>,
     ) -> Vec<ir::Control> {
-        if Self::approx_control_vec_size(&control_vec) <= self.threshold {
+        if Self::approx_control_vec_size(&control_vec) <= self.threshold
+            || !self.within_cycle_limit(
+                control_vec
+                    .iter()
+                    .map(Self::get_inferred_latency)
+                    .max()
+                    .unwrap_or_else(|| unreachable!("Non Empty Par Block")),
+            )
+        {
             // Return unchanged vec
             return control_vec;
         }
@@ -933,17 +966,22 @@ impl Visitor for StaticPromotion {
             } else {
                 // Accumualte cur_vec into a static seq if it meets threshold
                 let possibly_promoted_stmts =
-                    self.convert_vec_seq_if_threshold(&mut builder, cur_vec);
+                    self.convert_vec_seq_if_sat(&mut builder, cur_vec);
                 new_stmts.extend(possibly_promoted_stmts);
-                cur_vec = Vec::new();
                 // Add the current (non-promotable) stmt
                 new_stmts.push(stmt);
+                // New cur_vec
+                cur_vec = Vec::new();
             }
         }
         if new_stmts.is_empty() {
             // The entire seq can be promoted
             let approx_size: u64 = cur_vec.iter().map(Self::approx_size).sum();
-            if approx_size > self.threshold {
+            if approx_size > self.threshold
+                && self.within_cycle_limit(
+                    cur_vec.iter().map(Self::get_inferred_latency).sum(),
+                )
+            {
                 // Promote entire seq to a static seq
                 let s_seq_stmts =
                     self.convert_vec_to_static(&mut builder, cur_vec);
@@ -970,7 +1008,7 @@ impl Visitor for StaticPromotion {
         // Entire seq is not static, so we're only promoting the last
         // bit of it if possible.
         let possibly_promoted_stmts =
-            self.convert_vec_seq_if_threshold(&mut builder, cur_vec);
+            self.convert_vec_seq_if_sat(&mut builder, cur_vec);
         new_stmts.extend(possibly_promoted_stmts);
 
         let new_seq = ir::Control::Seq(ir::Seq {
@@ -997,7 +1035,15 @@ impl Visitor for StaticPromotion {
             });
         if d_stmts.is_empty() {
             // Entire par block can be promoted to static
-            if Self::approx_control_vec_size(&s_stmts) > self.threshold {
+            if Self::approx_control_vec_size(&s_stmts) > self.threshold
+                && self.within_cycle_limit(
+                    s_stmts
+                        .iter()
+                        .map(Self::get_inferred_latency)
+                        .max()
+                        .unwrap_or_else(|| unreachable!("Empty Par Block")),
+                )
+            {
                 // Promote entire par block to static
                 let static_par_stmts =
                     self.convert_vec_to_static(&mut builder, s_stmts);
@@ -1025,7 +1071,7 @@ impl Visitor for StaticPromotion {
         }
         // Otherwise just promote the par threads that we can into a static par
         let s_stmts_possibly_promoted =
-            self.convert_vec_par_if_threshold(&mut builder, s_stmts);
+            self.convert_vec_par_if_sat(&mut builder, s_stmts);
         new_stmts.extend(s_stmts_possibly_promoted);
         new_stmts.extend(d_stmts);
         let new_par = ir::Control::Par(ir::Par {
@@ -1050,16 +1096,18 @@ impl Visitor for StaticPromotion {
             let approx_size_if = Self::approx_size(&s.tbranch)
                 + Self::approx_size(&s.fbranch)
                 + APPROX_IF_SIZE;
-            if approx_size_if > self.threshold {
+            let latency = std::cmp::max(
+                Self::get_inferred_latency(&s.tbranch),
+                Self::get_inferred_latency(&s.fbranch),
+            );
+            if approx_size_if > self.threshold
+                && self.within_cycle_limit(latency)
+            {
                 // Meets size threshold so promote to static
                 let static_tbranch =
                     self.convert_to_static(&mut s.tbranch, &mut builder);
                 let static_fbranch =
                     self.convert_to_static(&mut s.fbranch, &mut builder);
-                let latency = std::cmp::max(
-                    static_tbranch.get_latency(),
-                    static_fbranch.get_latency(),
-                );
                 return Ok(Action::change(ir::Control::Static(
                     ir::StaticControl::static_if(
                         Rc::clone(&s.port),
@@ -1090,21 +1138,20 @@ impl Visitor for StaticPromotion {
         sigs: &LibrarySignatures,
         _comps: &[ir::Component],
     ) -> VisResult {
-        if self.stop_loop {
-            return Ok(Action::Continue);
-        }
         let mut builder = ir::Builder::new(comp, sigs);
         // First check that while loop is bounded
         if let Some(num_repeats) = s.get_attributes().get(ir::NumAttr::Bound) {
             // Then check that body is static/promotable
             if Self::can_be_promoted(&s.body) {
                 let approx_size =
                     Self::approx_size(&s.body) + APPROX_WHILE_REPEAT_SIZE;
+                let latency = Self::get_inferred_latency(&s.body) * num_repeats;
                 // Then check that it reaches the threshold
-                if approx_size > self.threshold {
+                if approx_size > self.threshold
+                    && self.within_cycle_limit(latency)
+                {
                     // Turn repeat into static repeat
                     let sc = self.convert_to_static(&mut s.body, &mut builder);
-                    let latency = sc.get_latency() * num_repeats;
                     let static_repeat = ir::StaticControl::repeat(
                         num_repeats,
                         latency,
@@ -1134,18 +1181,16 @@ impl Visitor for StaticPromotion {
         sigs: &LibrarySignatures,
         _comps: &[ir::Component],
     ) -> VisResult {
-        if self.stop_loop {
-            return Ok(Action::Continue);
-        }
         let mut builder = ir::Builder::new(comp, sigs);
         if Self::can_be_promoted(&s.body) {
             // Body can be promoted
             let approx_size =
                 Self::approx_size(&s.body) + APPROX_WHILE_REPEAT_SIZE;
-            if approx_size > self.threshold {
+            let latency = Self::get_inferred_latency(&s.body) * s.num_repeats;
+            if approx_size > self.threshold && self.within_cycle_limit(latency)
+            {
                 // Meets size threshold, so turn repeat into static repeat
                 let sc = self.convert_to_static(&mut s.body, &mut builder);
-                let latency = s.num_repeats * sc.get_latency();
                 let static_repeat = ir::StaticControl::repeat(
                     s.num_repeats,
                     latency,

examples/futil/dot-product.expect

@@ -99,7 +99,7 @@ component main(@go go: 1, @clk clk: 1, @reset reset: 1) -> (@done done: 1) {
     B0.clk = clk;
     B0.addr0 = fsm.out == 4'd0 & early_reset_static_seq_go.out ? i0.out;
     B0.reset = reset;
-    B_read0_0.write_en = (fsm.out == 4'd0 & fsm.out < 4'd7 | fsm.out == 4'd5 & fsm.out < 4'd7) & early_reset_static_seq_go.out ? 1'd1;
+    B_read0_0.write_en = (fsm.out == 4'd0 | fsm.out == 4'd5) & early_reset_static_seq_go.out ? 1'd1;
     B_read0_0.clk = clk;
     B_read0_0.reset = reset;
     B_read0_0.in = fsm.out == 4'd0 & early_reset_static_seq_go.out ? B0.read_data;
@@ -109,7 +109,7 @@ component main(@go go: 1, @clk clk: 1, @reset reset: 1) -> (@done done: 1) {
     early_reset_static_seq_done.in = ud0.out;
     tdcc_done.in = fsm0.out == 2'd3 ? 1'd1;
     while_wrapper_early_reset_static_seq_done.in = !comb_reg.out & fsm.out == 4'd0 ? 1'd1;
-    A_read0_0.write_en = (fsm.out == 4'd0 & fsm.out < 4'd7 | fsm.out == 4'd4 & fsm.out < 4'd7) & early_reset_static_seq_go.out ? 1'd1;
+    A_read0_0.write_en = (fsm.out == 4'd0 | fsm.out == 4'd4) & early_reset_static_seq_go.out ? 1'd1;
     A_read0_0.clk = clk;
     A_read0_0.reset = reset;
     A_read0_0.in = fsm.out == 4'd0 & early_reset_static_seq_go.out ? A0.read_data;

tests/passes/simplify-static-guards/basic.futil

@@ -14,15 +14,15 @@ component main(@go go: 1, @clk clk: 1, @reset reset: 1) -> (@done done: 1) {
   }
   wires {
     static<10> group my_group {
-      a.write_en = (%[2:3] | lt.out) & %[1:5] ? 1'd1; // don't simplify 
-      b.write_en = %[2:3] & (lt.out | gt.out) & %[1:5] ? 1'd1;  // %[1:5] is redundant 
+      a.write_en = (%[2:3] | lt.out) & %[1:5] ? 1'd1; // don't simplify
+      b.write_en = %[2:3] & (lt.out | gt.out) & %[1:5] ? 1'd1;  // %[1:5] is redundant
       c.write_en = %[2:5] & (%[5:7] | lt.out) & %[3:7] & %[4:10] ? 1'd1;  // %[5:7] shouldn't change, but can simplify rest to %[4:5]
-      d.write_en = %[2:5] & %[6:9] ? 1'd1; // assignment is false  
-      e.write_en = %[0:10] & lt.out ? 1'd1; // no static timing necesary, since %[0:10] is same as group 
-      a.in = 32'd1; 
-      b.in = 32'd2; 
-      c.in = 32'd3; 
-      d.in = 32'd4; 
+      d.write_en = %[2:5] & %[6:9] ? 1'd1; // assignment is false
+      e.write_en = %[0:10] & lt.out ? 1'd1; // no static timing necesary, since %[0:10] is same as group
+      a.in = 32'd1;
+      b.in = 32'd2;
+      c.in = 32'd3;
+      d.in = 32'd4;
     }
   }