feat(compiler)!: Enable tail calls by default (#1589)

* feat: Make Tail Calls Default

* fix: Disable Tail Calls In Near SmokeTest

* Update size of smallest grain program

---------

Co-authored-by: Oscar Spencer <oscar@grain-lang.org>

Author: spotandjake

cli/__test__/index.gr

@@ -1,4 +1,4 @@
-/* grainc-flags --no-gc --no-bulk-memory */
+/* grainc-flags --no-gc --no-bulk-memory --no-wasm-tail-call */
 module NearTest
 
 include "runtime/unsafe/wasmi32"

cli/__test__/nearEnv.gr

@@ -1,4 +1,4 @@
-/* grainc-flags --no-gc --no-bulk-memory */
+/* grainc-flags --no-gc --no-bulk-memory --no-wasm-tail-call */
 module NearEnv
 
 provide foreign wasm storage_read: (

compiler/src/codegen/compcore.re

@@ -1391,16 +1391,16 @@ let call_lambda =
   | Some(name) =>
     let instr =
       if (tail) {
-        if (Config.experimental_tail_call^) {
-          Expression.Call.make_return;
-        } else {
+        if (Config.no_tail_call^) {
           (
             (wasm_mod, name, args, retty) =>
               Expression.Return.make(
                 wasm_mod,
                 Expression.Call.make(wasm_mod, name, args, retty),
               )
           );
+        } else {
+          Expression.Call.make_return;
         };
       } else {
         Expression.Call.make;
@@ -1410,9 +1410,7 @@ let call_lambda =
   | None =>
     let instr =
       if (tail) {
-        if (Config.experimental_tail_call^) {
-          Expression.Call_indirect.make_return;
-        } else {
+        if (Config.no_tail_call^) {
           (
             (wasm_mod, table, ptr, args, argty, retty) =>
               Expression.Return.make(
@@ -1427,6 +1425,8 @@ let call_lambda =
                 ),
               )
           );
+        } else {
+          Expression.Call_indirect.make_return;
         };
       } else {
         Expression.Call_indirect.make;

compiler/src/utils/config.re

@@ -466,10 +466,10 @@ let compilation_mode =
 let statically_link =
   toggle_flag(~names=["no-link"], ~doc="Disable static linking", true);
 
-let experimental_tail_call =
+let no_tail_call =
   toggle_flag(
-    ~names=["experimental-wasm-tail-call"],
-    ~doc="Enables tail-call optimization",
+    ~names=["no-wasm-tail-call"],
+    ~doc="Disables tail-call optimization",
     false,
   );
 

compiler/src/utils/config.rei

@@ -90,9 +90,9 @@ let compilation_mode: ref(option(string));
 
 let statically_link: ref(bool);
 
-/** Enable tail-call optimizations */
+/** Disables tail-call optimizations */
 
-let experimental_tail_call: ref(bool);
+let no_tail_call: ref(bool);
 
 /** Whether to allow cyclic types. */
 

compiler/test/__snapshots__/basic_functionality.0996c5f7.0.snapshot

@@ -36,15 +36,13 @@ basic functionality › modulo4
   (local $4 f32)
   (local $5 f64)
   (block $compile_block.1
-   (return
-    (call $%_1113
-     (call $incRef_0
-      (global.get $GRAIN$EXPORT$incRef_0)
-      (global.get $%_1113)
-     )
-     (i32.const -33)
-     (i32.const 35)
+   (return_call $%_1113
+    (call $incRef_0
+     (global.get $GRAIN$EXPORT$incRef_0)
+     (global.get $%_1113)
     )
+    (i32.const -33)
+    (i32.const 35)
    )
   )
  )

compiler/test/__snapshots__/basic_functionality.0a230f18.0.snapshot

@@ -36,15 +36,13 @@ basic functionality › land4
   (local $4 f32)
   (local $5 f64)
   (block $compile_block.1
-   (return
-    (call $&_1113
-     (call $incRef_0
-      (global.get $GRAIN$EXPORT$incRef_0)
-      (global.get $&_1113)
-     )
-     (i32.const 1)
-     (i32.const 1)
+   (return_call $&_1113
+    (call $incRef_0
+     (global.get $GRAIN$EXPORT$incRef_0)
+     (global.get $&_1113)
     )
+    (i32.const 1)
+    (i32.const 1)
    )
   )
  )

compiler/test/__snapshots__/basic_functionality.0a2e4afa.0.snapshot

@@ -36,15 +36,13 @@ basic functionality › lxor1
   (local $4 f32)
   (local $5 f64)
   (block $compile_block.1
-   (return
-    (call $^_1113
-     (call $incRef_0
-      (global.get $GRAIN$EXPORT$incRef_0)
-      (global.get $^_1113)
-     )
-     (i32.const 3)
-     (i32.const 3)
+   (return_call $^_1113
+    (call $incRef_0
+     (global.get $GRAIN$EXPORT$incRef_0)
+     (global.get $^_1113)
     )
+    (i32.const 3)
+    (i32.const 3)
    )
   )
  )

compiler/test/__snapshots__/basic_functionality.0c0b170b.0.snapshot

@@ -36,15 +36,13 @@ basic functionality › lor1
   (local $4 f32)
   (local $5 f64)
   (block $compile_block.1
-   (return
-    (call $|_1113
-     (call $incRef_0
-      (global.get $GRAIN$EXPORT$incRef_0)
-      (global.get $|_1113)
-     )
-     (i32.const 3)
-     (i32.const 3)
+   (return_call $|_1113
+    (call $incRef_0
+     (global.get $GRAIN$EXPORT$incRef_0)
+     (global.get $|_1113)
     )
+    (i32.const 3)
+    (i32.const 3)
    )
   )
  )

compiler/test/__snapshots__/basic_functionality.0c400bde.0.snapshot

@@ -36,15 +36,13 @@ basic functionality › modulo6
   (local $4 f32)
   (local $5 f64)
   (block $compile_block.1
-   (return
-    (call $%_1113
-     (call $incRef_0
-      (global.get $GRAIN$EXPORT$incRef_0)
-      (global.get $%_1113)
-     )
-     (i32.const 35)
-     (i32.const 35)
+   (return_call $%_1113
+    (call $incRef_0
+     (global.get $GRAIN$EXPORT$incRef_0)
+     (global.get $%_1113)
     )
+    (i32.const 35)
+    (i32.const 35)
    )
   )
  )