Show expression uniformity in the Dot backend

bin/convert.rs

@@ -249,7 +249,7 @@ fn main() {
         #[cfg(feature = "dot-out")]
         "dot" => {
             use naga::back::dot;
-            let output = dot::write(&module).unwrap();
+            let output = dot::write(&module, analysis.as_ref()).unwrap();
             fs::write(output_path, output).unwrap();
         }
         other => {

src/back/dot/mod.rs

@@ -4,7 +4,10 @@
  * of IR inspection and debugging.
 !*/
 
-use crate::arena::Handle;
+use crate::{
+    arena::Handle,
+    proc::analyzer::{Analysis, FunctionInfo},
+};
 
 use std::{
     borrow::Cow,
@@ -140,7 +143,12 @@ const COLORS: &[&str] = &[
     "#d9d9d9",
 ];
 
-fn write_fun(output: &mut String, prefix: String, fun: &crate::Function) -> Result<(), FmtError> {
+fn write_fun(
+    output: &mut String,
+    prefix: String,
+    fun: &crate::Function,
+    info: Option<&FunctionInfo>,
+) -> Result<(), FmtError> {
     enum Payload<'a> {
         Arguments(&'a [Handle<crate::Expression>]),
         Local(Handle<crate::LocalVariable>),
@@ -312,11 +320,18 @@ fn write_fun(output: &mut String, prefix: String, fun: &crate::Function) -> Resu
                 (Cow::Borrowed("ArrayLength"), 7)
             }
         };
+
+        // give uniform expressions an outline
+        let color_attr = match info {
+            Some(info) if info[handle].uniformity.non_uniform_result.is_none() => "fillcolor",
+            _ => "color",
+        };
         writeln!(
             output,
-            "\t\t{}_e{} [ color=\"{}\" label=\"{:?} {}\" ]",
+            "\t\t{}_e{} [ {}=\"{}\" label=\"{:?} {}\" ]",
             prefix,
             handle.index(),
+            color_attr,
             COLORS[color_id],
             handle,
             label,
@@ -354,7 +369,7 @@ fn write_fun(output: &mut String, prefix: String, fun: &crate::Function) -> Resu
             Some(Payload::Global(h)) => {
                 writeln!(
                     output,
-                    "\t\tg{} -> {}_e{} [color=gray]",
+                    "\t\tg{} -> {}_e{} [fillcolor=gray]",
                     h.index(),
                     prefix,
                     handle.index(),
@@ -414,7 +429,7 @@ fn write_fun(output: &mut String, prefix: String, fun: &crate::Function) -> Resu
     Ok(())
 }
 
-pub fn write(module: &crate::Module) -> Result<String, FmtError> {
+pub fn write(module: &crate::Module, analysis: Option<&Analysis>) -> Result<String, FmtError> {
     use std::fmt::Write as _;
 
     let mut output = String::new();
@@ -443,14 +458,16 @@ pub fn write(module: &crate::Module) -> Result<String, FmtError> {
             handle,
             name(&fun.name)
         )?;
-        write_fun(&mut output, prefix, fun)?;
+        let info = analysis.map(|a| &a[handle]);
+        write_fun(&mut output, prefix, fun, info)?;
         writeln!(output, "\t}}")?;
     }
     for (ep_index, ep) in module.entry_points.iter().enumerate() {
         let prefix = format!("ep{}", ep_index);
         writeln!(output, "\tsubgraph cluster_{} {{", prefix)?;
         writeln!(output, "\t\tlabel=\"{:?}/'{}'\"", ep.stage, ep.name)?;
-        write_fun(&mut output, prefix, &ep.function)?;
+        let info = analysis.map(|a| a.get_entry_point(ep_index));
+        write_fun(&mut output, prefix, &ep.function, info)?;
         writeln!(output, "\t}}")?;
     }
 

tests/out/quad.dot.snap

@@ -12,7 +12,7 @@ digraph Module {
 		label="Vertex/'main'"
 		node [ style=filled ]
 		ep0_l0 [ shape=hexagon label="[1] 'out'" ]
-		ep0_e0 [ color="#ffffb3" label="[1] Constant" ]
+		ep0_e0 [ fillcolor="#ffffb3" label="[1] Constant" ]
 		ep0_e1 [ color="#8dd3c7" label="[2] Argument[0]" ]
 		ep0_e2 [ color="#8dd3c7" label="[3] Argument[1]" ]
 		ep0_e3 [ color="#8dd3c7" label="[4] Local" ]
@@ -24,8 +24,8 @@ digraph Module {
 		ep0_e6 [ color="#fdb462" label="[7] Multiply" ]
 		ep0_e1 -> ep0_e6 [ label="right" ]
 		ep0_e0 -> ep0_e6 [ label="left" ]
-		ep0_e7 [ color="#ffffb3" label="[8] Constant" ]
-		ep0_e8 [ color="#ffffb3" label="[9] Constant" ]
+		ep0_e7 [ fillcolor="#ffffb3" label="[8] Constant" ]
+		ep0_e8 [ fillcolor="#ffffb3" label="[9] Constant" ]
 		ep0_e9 [ color="#bebada" label="[10] Compose" ]
 		{ ep0_e6 ep0_e7 ep0_e8 } -> ep0_e9
 		ep0_e10 [ color="#fb8072" label="[11] Load" ]
@@ -59,11 +59,11 @@ digraph Module {
 	subgraph cluster_ep1 {
 		label="Fragment/'main'"
 		node [ style=filled ]
-		ep1_e0 [ color="#ffffb3" label="[1] Constant" ]
-		ep1_e1 [ color="#ffffb3" label="[2] Global" ]
-		g1 -> ep1_e1 [color=gray]
-		ep1_e2 [ color="#ffffb3" label="[3] Global" ]
-		g0 -> ep1_e2 [color=gray]
+		ep1_e0 [ fillcolor="#ffffb3" label="[1] Constant" ]
+		ep1_e1 [ fillcolor="#ffffb3" label="[2] Global" ]
+		g1 -> ep1_e1 [fillcolor=gray]
+		ep1_e2 [ fillcolor="#ffffb3" label="[3] Global" ]
+		g0 -> ep1_e2 [fillcolor=gray]
 		ep1_e3 [ color="#8dd3c7" label="[4] Argument[0]" ]
 		ep1_e4 [ color="#80b1d3" label="[5] ImageSample" ]
 		ep1_e1 -> ep1_e4 [ label="sampler" ]
@@ -71,7 +71,7 @@ digraph Module {
 		ep1_e3 -> ep1_e4 [ label="coordinate" ]
 		ep1_e5 [ color="#8dd3c7" label="[6] AccessIndex[3]" ]
 		ep1_e4 -> ep1_e5 [ label="base" ]
-		ep1_e6 [ color="#ffffb3" label="[7] Constant" ]
+		ep1_e6 [ fillcolor="#ffffb3" label="[7] Constant" ]
 		ep1_e7 [ color="#fdb462" label="[8] Equal" ]
 		ep1_e6 -> ep1_e7 [ label="right" ]
 		ep1_e5 -> ep1_e7 [ label="left" ]

tests/snapshots.rs

@@ -106,7 +106,7 @@ fn check_targets(module: &naga::Module, name: &str, targets: Targets) {
     #[cfg(feature = "dot-out")]
     {
         if targets.contains(Targets::DOT) {
-            let string = naga::back::dot::write(module).unwrap();
+            let string = naga::back::dot::write(module, Some(&analysis)).unwrap();
             with_snapshot_settings(|| {
                 insta::assert_snapshot!(format!("{}.dot", name), string);
             });