preventing deduplication to cause bugs

lang/README.md

@@ -612,6 +612,30 @@ main := fn(): uint {
 
 ### Purely Testing Examples
 
+#### scheduling_block_did_dirty
+```hb
+Struct := struct {
+	pad: uint,
+	pad2: uint,
+}
+
+file := [u8].(255)
+
+opaque := fn(x: uint): uint {
+	return file[x]
+}
+
+constructor := fn(x: uint): Struct {
+	a := opaque(x)
+	return .(a, a)
+}
+
+main := fn(): void {
+	something := constructor(0)
+	return
+}
+```
+
 #### null_check_returning_small_global
 ```hb
 MAGIC := 127

lang/src/son.rs

@@ -4079,9 +4079,10 @@ impl<'a> Codegen<'a> {
         self.pool.push_ci(file, Some(sig.ret), 0, &mut self.ci);
         let prev_err_len = self.errors.borrow().len();
 
-        let &Expr::Closure { body, args, .. } = expr else {
+        let &Expr::Closure { body, args, pos, .. } = expr else {
             unreachable!("{}", self.ast_display(expr))
         };
+        self.ci.pos.push(pos);
 
         let mut tys = sig.args.args();
         let mut args = args.iter();
@@ -4142,6 +4143,7 @@ impl<'a> Codegen<'a> {
             backend.emit_body(id, &mut self.ci.nodes, self.tys, self.files);
         }
 
+        self.ci.pos.pop();
         self.pool.pop_ci(&mut self.ci);
     }
 
@@ -4646,6 +4648,7 @@ mod tests {
         fb_driver;
 
         // Purely Testing Examples;
+        scheduling_block_did_dirty;
         null_check_returning_small_global;
         null_check_in_the_loop;
         stack_provenance;

lang/src/son/hbvm/my_regalloc.rs

@@ -10,7 +10,7 @@ use {
         Offset, PLoc, Reloc, Sig, TypedReloc, Types,
     },
     alloc::{borrow::ToOwned, vec::Vec},
-    core::{mem, ops::Range, u32, usize},
+    core::{mem, ops::Range},
     hbbytecode::{self as instrs},
 };
 

lang/src/son/hbvm/their_regalloc.rs

@@ -855,6 +855,7 @@ impl<'a> Function<'a> {
     }
 
     fn reschedule_block(&mut self, from: Nid, outputs: &mut Vc) {
+        // NOTE: this code is horible
         let from = Some(&from);
         let mut buf = Vec::with_capacity(outputs.len());
         let mut seen = BitSet::default();
@@ -878,7 +879,9 @@ impl<'a> Function<'a> {
                             .all(|&o| self.nodes[o].inputs.first() != from || seen.get(o))
                         && seen.set(i)
                     {
-                        buf.push(i);
+                        for &o in outputs.iter().filter(|&&n| n == i) {
+                            buf.push(o);
+                        }
                     }
                 }
                 cursor += 1;
@@ -890,7 +893,9 @@ impl<'a> Function<'a> {
                 continue;
             }
             let mut cursor = buf.len();
-            buf.push(o);
+            for &o in outputs.iter().filter(|&&n| n == o) {
+                buf.push(o);
+            }
             while let Some(&n) = buf.get(cursor) {
                 for &i in &self.nodes[n].inputs[1..] {
                     if from == self.nodes[i].inputs.first()
@@ -900,22 +905,17 @@ impl<'a> Function<'a> {
                             .all(|&o| self.nodes[o].inputs.first() != from || seen.get(o))
                         && seen.set(i)
                     {
-                        buf.push(i);
+                        for &o in outputs.iter().filter(|&&n| n == i) {
+                            buf.push(o);
+                        }
                     }
                 }
                 cursor += 1;
             }
         }
 
-        debug_assert!(
-            outputs.len() == buf.len() || outputs.len() == buf.len() + 1,
-            "{:?} {:?}",
-            outputs,
-            buf
-        );
-
-        if buf.len() + 1 == outputs.len() {
-            outputs.remove(outputs.len() - 1);
+        if outputs.len() != buf.len() {
+            panic!("{:?} {:?}", outputs, buf);
         }
         outputs.copy_from_slice(&buf);
     }

lang/tests/son_tests_scheduling_block_did_dirty.txt

@@ -0,0 +1,31 @@
+constructor:
+    ADDI64 r254, r254, -32d
+    ST r31, r254, 16a, 16h
+    CP r2, r3
+    JAL r31, r0, :opaque
+    ADDI64 r32, r254, 0d
+    ST r1, r254, 0a, 8h
+    ST r1, r254, 8a, 8h
+    LD r1, r32, 0a, 16h
+    LD r31, r254, 16a, 16h
+    ADDI64 r254, r254, 32d
+    JALA r0, r31, 0a
+main:
+    ADDI64 r254, r254, -32d
+    ST r31, r254, 16a, 16h
+    ADDI64 r32, r254, 0d
+    LI64 r3, 0d
+    JAL r31, r0, :constructor
+    ST r1, r254, 0a, 16h
+    LD r31, r254, 16a, 16h
+    ADDI64 r254, r254, 32d
+    JALA r0, r31, 0a
+opaque:
+    LRA r3, r0, :file
+    ADD64 r5, r3, r2
+    LD r7, r5, 0a, 1h
+    ANDI r1, r7, 255d
+    JALA r0, r31, 0a
+code size: 274
+ret: 255
+status: Ok(())