port mapping, inputs on OLMC outputs consume the OLMC

compiler/src/fitter.rs

@@ -1,5 +1,5 @@
 use crate::pcf::PcfFile;
-use crate::yosys_parser::{GalOLMC, GalSop, Graph, NamedPort, Net, Node, NodeIdx};
+use crate::yosys_parser::{GalOLMC, GalSop, Graph, NamedPort, Net, Node, NodeIdx, PortDirection};
 use galette::blueprint::Blueprint;
 use galette::chips::Chip;
 use log::info;
@@ -16,8 +16,8 @@ pub enum MappingError {
     #[error("Could not find the SOP input")]
     MissingSOP,
 
-    #[error("Could not find a sop to fit {0}")]
-    SopTooBig(usize),
+    #[error("Could not find a sop to fit SOP {0:?} of {1}")]
+    SopTooBig(String, usize),
 
     #[error("Unknown error")]
     Unknown,
@@ -40,47 +40,83 @@ fn get_sop_for_olmc(graph: &Graph, olmc_idx: NodeIdx) -> Result<GalSop, MappingE
     }
 }
 
-fn map_remaining_olcm(graph: &Graph, olmc: NodeIdx, unused: Vec<(usize, usize)>) -> Result<usize, MappingError> {
+fn map_remaining_olmc(
+    graph: &Graph,
+    olmc: NodeIdx,
+    unused: &Vec<(usize, usize)>,
+) -> Result<(usize, usize), MappingError> {
     // (index, size)
     let mut chosen_row: Option<(usize, usize)> = None;
     // FIXME: implement.
-    let sopsize: usize = get_sop_for_olmc(graph, olmc)?.parameters.depth as usize;
+    let sop = get_sop_for_olmc(graph, olmc)?;
+    let sopsize: usize = sop.parameters.depth as usize;
 
     for (olmc_idx, size) in unused {
         match chosen_row {
             None => {
-                if size > sopsize {
-                    chosen_row = Some((olmc_idx, size));
+                if size > &sopsize {
+                    chosen_row = Some((*olmc_idx, *size));
                 }
             }
             Some(r) => {
                 // we do the comparison (size > SOP Size)
-                if size < r.1 && size > sopsize {
-                    chosen_row = Some((olmc_idx, size));
+                if size < &r.1 && size > &sopsize {
+                    chosen_row = Some((*olmc_idx, *size));
                 }
             }
         }
     }
     // at the end, if we have chosen a row, we can swap it in.
     match chosen_row {
-        Some((row, size)) => {
-            info!("mapping {olmc:?} size {sopsize} to row {row} with size {size}");
-            Ok(row)
-        },
-        None => {
-            Err(MappingError::SopTooBig(sopsize))
+        Some(x) => {
+            info!(
+                "mapping {olmc:?} size {sopsize} to row {} with size {}",
+                x.0, x.1
+            );
+            Ok(x)
         }
+        None => Err(MappingError::SopTooBig("TODO FIXME".to_string(), sopsize)),
     }
 }
 
+fn valid_inputs(chip: Chip) -> Vec<u32> {
+    match chip {
+        Chip::GAL16V8 => vec![
+            1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 15, 16, 17, 18, 19,
+        ],
+        Chip::GAL22V10 => vec![
+            1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
+        ],
+        _ => panic!("unsupported chip"),
+    }
+}
 
 pub fn graph_convert(graph: &Graph, pcf: PcfFile, chip: Chip) -> anyhow::Result<Blueprint> {
     let mut bp = Blueprint::new(chip);
 
+    // phase zero: input mapping.
+    let mut pinmap: Vec<Option<String>> = vec![None; chip.num_pins()];
+
+    let valid_inp = valid_inputs(chip);
+    let mut olmcmap: Vec<Option<NodeIdx>> = vec![None; chip.num_olmcs()];
+
+    for port in &graph.ports {
+        let pin = port
+            .lookup(&pcf)
+            .ok_or(MappingError::MissingConstraint(port.clone()))?;
+        if valid_inp.contains(&pin) {
+            if let Some(olmcrow) = chip.pin_to_olmc(pin as usize) {
+                if port.direction == PortDirection::Input {
+                    olmcmap[olmcrow] = Some(NodeIdx(usize::MAX));
+                } // otherwise we do not care!
+            }
+        } else {
+            return Err(MappingError::Unknown.into());
+        }
+    }
+
     // phase one: OLMC mapping
     // start by finding the constraints.
-    //
-    let mut olmcmap: Vec<Option<NodeIdx>> = vec![None; chip.num_olmcs()];
 
     let mut deferrals: Vec<NodeIdx> = Vec::new();
 
@@ -108,7 +144,14 @@ pub fn graph_convert(graph: &Graph, pcf: PcfFile, chip: Chip) -> anyhow::Result<
                     .pin_to_olmc(pin.try_into()?)
                     .ok_or(MappingError::Unknown)?;
                 // TODO: check size of row vs size of SOP
+                // FIXME: -0 to size if registered, if comb, size - 1
                 info!("Found a real pin to map: Mapping node {o:?} onto row {olmc_row}");
+
+                // check if OLMC row is already in use
+                if let Some(o) = olmcmap[olmc_row] {
+                    info!("already exists in {o:?}");
+                    return Err(MappingError::Unknown.into());
+                }
                 olmcmap[olmc_row] = Some(o);
             }
             None => {
@@ -124,14 +167,24 @@ pub fn graph_convert(graph: &Graph, pcf: PcfFile, chip: Chip) -> anyhow::Result<
     // to map remainders, we need to find the smallest SOP.
     //
     // Vec<(olmc_index,size)>
-    let unused_rows = olmcmap
+    let mut unused_rows = olmcmap
         .iter()
-        .enumerate()
-        .filter_map(|(i, x)| if !x.is_some() { Some(i) } else { None })
-        .map(|i| (i, chip.num_rows_for_olmc(i)));
-    // find the smallest row that fits.
+        .enumerate() // get the index
+        .filter_map(|(i, x)| if x.is_none() { Some(i) } else { None }) // find the ones that are
+        .map(|i| (i, chip.num_rows_for_olmc(i)))
+        .collect();
 
-    let olmc = deferrals[0];
+    // find the smallest row that fits.
+    for olmc in deferrals {
+        let row = map_remaining_olmc(graph, olmc, &unused_rows)?;
+        // insert into the mapping
+        olmcmap[row.0] = Some(olmc);
+        // remove this row from the available rows
+        // i.e only keep those that are not equal to this row.
+        unused_rows.retain(|r| r != &row);
+    }
+
+    // at this point, we have mapped every OLMC.
 
     Ok(bp)
 }

compiler/src/yosys_parser.rs

@@ -64,9 +64,9 @@ pub struct GalSop {
 #[serde(rename_all = "UPPERCASE")]
 pub struct GALOLMCParameters {
     #[serde(deserialize_with = "bool_from_binstr")]
-    inverted: bool,
+    pub inverted: bool,
     #[serde(deserialize_with = "bool_from_binstr")]
-    registered: bool,
+    pub registered: bool,
 }
 
 #[derive(Clone, Debug, Serialize, Deserialize, PartialEq)]
@@ -187,8 +187,8 @@ pub enum PortDirection {
 #[derive(Debug, Clone, PartialEq, PartialOrd)]
 pub struct NamedPort {
     pub name: String,
-    net: Net,
-    direction: PortDirection,
+    pub net: Net,
+    pub direction: PortDirection,
 }
 
 use std::cmp::Ordering;
@@ -228,7 +228,7 @@ impl NamedPort {
 
 /// NodeIdx is an index into the node list to reference a specific node.
 #[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
-pub struct NodeIdx(usize);
+pub struct NodeIdx(pub usize);
 
 
 #[derive(Debug, Clone)]