fix(compiler): Do not inline aliased mutables (grain-lang#909)

spotandjake · Sep 19, 2021 · a50430a · a50430a
1 parent d3b60a4
commit a50430a
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Showing 22 changed files with 605 additions and 98 deletions.
diff --git a/compiler/src/middle_end/analyze_mutable_vars.re b/compiler/src/middle_end/analyze_mutable_vars.re
@@ -0,0 +1,28 @@
+open Anftree;
+open Grain_typed;
+
+let mutable_vars = ref(Ident.Set.empty);
+
+let is_mutable = id => Ident.Set.mem(id, mutable_vars^);
+
+module MutableVarsArg = {
+  include Anf_iterator.DefaultIterArgument;
+
+  let enter_anf_expression = ({anf_desc}) => {
+    switch (anf_desc) {
+    | AELet(_, _, Mutable, binds, _) =>
+      List.iter(
+        ((id, _)) => {mutable_vars := Ident.Set.add(id, mutable_vars^)},
+        binds,
+      )
+    | _ => ()
+    };
+  };
+};
+
+module MutableVarsIter = Anf_iterator.MakeIter(MutableVarsArg);
+
+let analyze = prog => {
+  mutable_vars := Ident.Set.empty;
+  MutableVarsIter.iter_anf_program(prog);
+};
diff --git a/compiler/src/middle_end/analyze_mutable_vars.rei b/compiler/src/middle_end/analyze_mutable_vars.rei
@@ -0,0 +1,3 @@
+let is_mutable: Grain_typed.Ident.t => bool;
+
+let analyze: Anftree.anf_program => unit;
diff --git a/compiler/src/middle_end/optimize.re b/compiler/src/middle_end/optimize.re
@@ -6,6 +6,7 @@ let analysis_passes = [
   Analyze_tail_calls.analyze,
   Analyze_inline_wasm.analyze,
   Analyze_closure_scoped_vars.analyze,
+  Analyze_mutable_vars.analyze,
 ];
 
 let optimization_passes = [

diff --git a/compiler/src/middle_end/optimize_constants.re b/compiler/src/middle_end/optimize_constants.re
@@ -22,7 +22,13 @@ module ConstantPropagationArg: Anf_mapper.MapArgument = {
                 Int64.compare(n, Literals.simple_number_max) < 0
                 && Int64.compare(n, Literals.simple_number_min) > 0 =>
             add_constant(id, ImmConst(Const_number(c')))
-          | {comp_desc: CImmExpr({imm_desc})} => add_constant(id, imm_desc)
+          | {comp_desc: CImmExpr({imm_desc})} =>
+            switch (imm_desc) {
+            // We don't substitute mutable variables, since we do pass-by-value, not pass-by-reference
+            | ImmId(rhs_id) when Analyze_mutable_vars.is_mutable(rhs_id) =>
+              ()
+            | _ => add_constant(id, imm_desc)
+            }
           | _ => ()
           },
         binds,

diff --git a/compiler/test/__snapshots__/let_mut.00e05fe2.0.snapshot b/compiler/test/__snapshots__/let_mut.00e05fe2.0.snapshot
@@ -21,6 +21,7 @@ let mut › let-mut_division1
   (local $0 i32)
   (local $1 i32)
   (local $2 i32)
+  (local $3 i32)
   (local.set $1
    (tuple.extract 0
     (tuple.make
@@ -37,6 +38,20 @@ let mut › let-mut_division1
        )
       )
       (local.set $2
+       (tuple.extract 0
+        (tuple.make
+         (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
+          (local.get $0)
+         )
+         (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+          (i32.const 0)
+         )
+        )
+       )
+      )
+      (local.set $3
        (tuple.extract 0
         (tuple.make
          (call_indirect (type $i32_i32_i32_=>_i32)
@@ -53,7 +68,7 @@ let mut › let-mut_division1
           )
           (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
            (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-           (local.get $0)
+           (local.get $2)
           )
           (i32.const 39)
           (i32.load offset=8
@@ -72,7 +87,7 @@ let mut › let-mut_division1
         (tuple.make
          (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
           (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-          (local.get $2)
+          (local.get $3)
          )
          (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
           (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
@@ -99,6 +114,12 @@ let mut › let-mut_division1
     (local.get $2)
    )
   )
+  (drop
+   (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+    (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+    (local.get $3)
+   )
+  )
   (drop
    (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
     (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)

diff --git a/compiler/test/__snapshots__/let_mut.1176df90.0.snapshot b/compiler/test/__snapshots__/let_mut.1176df90.0.snapshot
@@ -22,6 +22,7 @@ let mut › let-mut_multiplication2
   (local $1 i32)
   (local $2 i32)
   (local $3 i32)
+  (local $4 i32)
   (local.set $1
    (tuple.extract 0
     (tuple.make
@@ -38,6 +39,20 @@ let mut › let-mut_multiplication2
        )
       )
       (local.set $2
+       (tuple.extract 0
+        (tuple.make
+         (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
+          (local.get $0)
+         )
+         (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+          (i32.const 0)
+         )
+        )
+       )
+      )
+      (local.set $3
        (tuple.extract 0
         (tuple.make
          (call_indirect (type $i32_i32_i32_=>_i32)
@@ -54,7 +69,7 @@ let mut › let-mut_multiplication2
           )
           (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
            (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-           (local.get $0)
+           (local.get $2)
           )
           (i32.const 39)
           (i32.load offset=8
@@ -68,7 +83,7 @@ let mut › let-mut_multiplication2
         )
        )
       )
-      (local.set $3
+      (local.set $4
        (tuple.extract 0
         (tuple.make
          (block (result i32)
@@ -77,7 +92,7 @@ let mut › let-mut_multiplication2
             (tuple.make
              (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
               (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-              (local.get $2)
+              (local.get $3)
              )
              (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
               (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
@@ -122,6 +137,12 @@ let mut › let-mut_multiplication2
     (local.get $3)
    )
   )
+  (drop
+   (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+    (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+    (local.get $4)
+   )
+  )
   (local.get $1)
  )
  (func $_start (; has Stack IR ;)

diff --git a/compiler/test/__snapshots__/let_mut.3307d5a7.0.snapshot b/compiler/test/__snapshots__/let_mut.3307d5a7.0.snapshot
@@ -21,6 +21,7 @@ let mut › let-mut3
   (local $0 i32)
   (local $1 i32)
   (local $2 i32)
+  (local $3 i32)
   (local.set $0
    (tuple.extract 0
     (tuple.make
@@ -66,6 +67,20 @@ let mut › let-mut3
         )
        )
       )
+      (local.set $3
+       (tuple.extract 0
+        (tuple.make
+         (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
+          (local.get $2)
+         )
+         (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+          (i32.const 0)
+         )
+        )
+       )
+      )
       (call_indirect (type $i32_i32_=>_i32)
        (local.tee $0
         (tuple.extract 0
@@ -80,7 +95,7 @@ let mut › let-mut3
        )
        (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
         (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-        (local.get $2)
+        (local.get $3)
        )
        (i32.load offset=8
         (local.get $0)
@@ -103,6 +118,12 @@ let mut › let-mut3
     (local.get $2)
    )
   )
+  (drop
+   (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+    (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+    (local.get $3)
+   )
+  )
   (drop
    (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
     (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)

diff --git a/compiler/test/__snapshots__/let_mut.43f6980c.0.snapshot b/compiler/test/__snapshots__/let_mut.43f6980c.0.snapshot
@@ -22,6 +22,7 @@ let mut › let-mut_division3
   (local $1 i32)
   (local $2 i32)
   (local $3 i32)
+  (local $4 i32)
   (local.set $1
    (tuple.extract 0
     (tuple.make
@@ -38,6 +39,20 @@ let mut › let-mut_division3
        )
       )
       (local.set $2
+       (tuple.extract 0
+        (tuple.make
+         (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
+          (local.get $0)
+         )
+         (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+          (i32.const 0)
+         )
+        )
+       )
+      )
+      (local.set $3
        (tuple.extract 0
         (tuple.make
          (call_indirect (type $i32_i32_i32_=>_i32)
@@ -54,7 +69,7 @@ let mut › let-mut_division3
           )
           (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
            (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-           (local.get $0)
+           (local.get $2)
           )
           (i32.const 39)
           (i32.load offset=8
@@ -68,7 +83,7 @@ let mut › let-mut_division3
         )
        )
       )
-      (local.set $3
+      (local.set $4
        (tuple.extract 0
         (tuple.make
          (block (result i32)
@@ -77,7 +92,7 @@ let mut › let-mut_division3
             (tuple.make
              (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
               (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-              (local.get $2)
+              (local.get $3)
              )
              (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
               (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
@@ -122,6 +137,12 @@ let mut › let-mut_division3
     (local.get $3)
    )
   )
+  (drop
+   (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+    (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+    (local.get $4)
+   )
+  )
   (local.get $1)
  )
  (func $_start (; has Stack IR ;)

diff --git a/compiler/test/__snapshots__/let_mut.48249b50.0.snapshot b/compiler/test/__snapshots__/let_mut.48249b50.0.snapshot
@@ -22,6 +22,7 @@ let mut › let-mut5
   (local $1 i32)
   (local $2 i32)
   (local $3 i32)
+  (local $4 i32)
   (local.set $1
    (tuple.extract 0
     (tuple.make
@@ -38,6 +39,20 @@ let mut › let-mut5
        )
       )
       (local.set $2
+       (tuple.extract 0
+        (tuple.make
+         (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
+          (local.get $0)
+         )
+         (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+          (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+          (i32.const 0)
+         )
+        )
+       )
+      )
+      (local.set $3
        (tuple.extract 0
         (tuple.make
          (call_indirect (type $i32_i32_i32_=>_i32)
@@ -54,7 +69,7 @@ let mut › let-mut5
           )
           (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
            (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-           (local.get $0)
+           (local.get $2)
           )
           (i32.const 3)
           (i32.load offset=8
@@ -68,7 +83,7 @@ let mut › let-mut5
         )
        )
       )
-      (local.set $3
+      (local.set $4
        (tuple.extract 0
         (tuple.make
          (block (result i32)
@@ -77,7 +92,7 @@ let mut › let-mut5
             (tuple.make
              (call $import_GRAIN$MODULE$runtime/gc_0_incRef_0
               (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$incRef_0)
-              (local.get $2)
+              (local.get $3)
              )
              (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
               (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
@@ -122,6 +137,12 @@ let mut › let-mut5
     (local.get $3)
    )
   )
+  (drop
+   (call $import_GRAIN$MODULE$runtime/gc_0_decRefIgnoreZeros_0
+    (global.get $import_GRAIN$MODULE$runtime/gc_0_GRAIN$EXPORT$decRefIgnoreZeros_0)
+    (local.get $4)
+   )
+  )
   (local.get $1)
  )
  (func $_start (; has Stack IR ;)
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,3 @@
		let is_mutable: Grain_typed.Ident.t => bool;

		let analyze: Anftree.anf_program => unit;