From 6bf5a1b39647c4e4a2ca2874e827073472e259a1 Mon Sep 17 00:00:00 2001
From: Joe Savona <joesavona@fb.com>
Date: Tue, 22 Nov 2022 08:03:40 -0800
Subject: [PATCH] [codegen] Elide final return stmt if no value
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This is a random driveby improvement. I realized that we can eliminate `return`
statements if a) they have no value and b) they are in the top-level block.
Functions implicitly return at that point — there can't be any succeeding
instructions anyway — so we can save bytes in the output.
---
 compiler/forget/src/HIR/Codegen.ts               |  8 ++++++++
 .../__tests__/fixtures/hir/alias-while.expect.md |  4 +---
 .../fixtures/hir/assignment-variations.expect.md |  2 --
 .../src/__tests__/fixtures/hir/call.expect.md    |  4 +---
 .../fixtures/hir/complex-while.expect.md         |  1 -
 .../hir/conditional-on-mutable.expect.md         |  8 ++------
 .../__tests__/fixtures/hir/constructor.expect.md |  4 +---
 .../fixtures/hir/frozen-after-alias.expect.md    |  9 ++-------
 .../__tests__/fixtures/hir/hook-call.expect.md   |  8 ++------
 .../hir/hooks-freeze-arguments.expect.md         |  8 ++------
 ...s-freeze-possibly-mutable-arguments.expect.md |  8 ++------
 .../fixtures/hir/independent-across-if.expect.md | 16 ++++------------
 .../__tests__/fixtures/hir/independent.expect.md | 12 +++---------
 .../hir/interdependent-across-if.expect.md       | 12 +++---------
 .../fixtures/hir/interdependent.expect.md        | 12 +++---------
 .../__tests__/fixtures/hir/inverted-if.expect.md |  2 --
 .../fixtures/hir/logical-expression.expect.md    |  8 ++------
 .../hir/mutable-lifetime-loops.expect.md         |  9 ++-------
 .../hir/mutable-lifetime-with-aliasing.expect.md |  5 +----
 .../hir/mutable-liverange-loop.expect.md         |  9 ++-------
 .../fixtures/hir/reverse-postorder.expect.md     |  1 -
 .../fixtures/hir/simple-alias.expect.md          |  4 +---
 .../fixtures/hir/ssa-call-jsx-2.expect.md        |  4 +---
 .../fixtures/hir/ssa-call-jsx.expect.md          |  4 +---
 .../hir/ssa-complex-multiple-if.expect.md        |  1 -
 .../fixtures/hir/ssa-complex-single-if.expect.md |  1 -
 .../__tests__/fixtures/hir/ssa-if-else.expect.md |  2 --
 .../fixtures/hir/ssa-newexpression.expect.md     |  4 +---
 .../fixtures/hir/ssa-shadowing.expect.md         |  5 +----
 .../fixtures/hir/ssa-simple-phi.expect.md        |  1 -
 .../__tests__/fixtures/hir/ssa-simple.expect.md  |  1 -
 .../fixtures/hir/ssa-single-if.expect.md         |  2 --
 .../__tests__/fixtures/hir/ssa-switch.expect.md  |  1 -
 .../hir/switch-with-fallthrough.expect.md        |  2 --
 .../hir/while-conditional-continue.expect.md     |  1 -
 35 files changed, 46 insertions(+), 137 deletions(-)

diff --git a/compiler/forget/src/HIR/Codegen.ts b/compiler/forget/src/HIR/Codegen.ts
index c095f1576c..6193788757 100644
--- a/compiler/forget/src/HIR/Codegen.ts
+++ b/compiler/forget/src/HIR/Codegen.ts
@@ -94,9 +94,11 @@ class CodegenVisitor
       t.SwitchCase
     >
 {
+  depth: number = 0;
   temp: Map<IdentifierId, t.Expression> = new Map();
 
   enterBlock(): t.Statement[] {
+    this.depth++;
     return [];
   }
   visitValue(
@@ -190,6 +192,11 @@ class CodegenVisitor
       case "return": {
         if (terminal.value !== null) {
           return t.returnStatement(terminal.value);
+        } else if (this.depth === 1) {
+          // A return at the top-level of a function must be the last instruction,
+          // and functions implicitly return after the last instruction of the top-level.
+          // Elide the return.
+          return t.emptyStatement();
         } else {
           return t.returnStatement();
         }
@@ -223,6 +230,7 @@ class CodegenVisitor
     }
   }
   leaveBlock(block: t.Statement[]): t.Statement {
+    this.depth--;
     return t.blockStatement(block);
   }
 }
diff --git a/compiler/forget/src/__tests__/fixtures/hir/alias-while.expect.md b/compiler/forget/src/__tests__/fixtures/hir/alias-while.expect.md
index 2df6d5560d..9bd48ba87f 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/alias-while.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/alias-while.expect.md
@@ -140,9 +140,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function mutate$0(x$1, y$2) {
-  return;
-}
+function mutate$0(x$1, y$2) {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/assignment-variations.expect.md b/compiler/forget/src/__tests__/fixtures/hir/assignment-variations.expect.md
index 369e7f9992..5585422a05 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/assignment-variations.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/assignment-variations.expect.md
@@ -60,7 +60,6 @@ function f$0() {
   x$1 = x$1 + 1;
   x$1 = x$1 + 1;
   x$1 = x$1 >>> 1;
-  return;
 }
 
 ```
@@ -100,7 +99,6 @@ flowchart TB
 function g$0(a$1) {
   a$1.c.b = a$1.b.c + 1;
   a$1.c.b = a$1.b.c * 2;
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/call.expect.md b/compiler/forget/src/__tests__/fixtures/hir/call.expect.md
index f03d6b1af4..4628ec5806 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/call.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/call.expect.md
@@ -38,9 +38,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/complex-while.expect.md b/compiler/forget/src/__tests__/fixtures/hir/complex-while.expect.md
index 1c4a6595e6..167b2ff5a6 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/complex-while.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/complex-while.expect.md
@@ -83,7 +83,6 @@ function foo$0(a$1, b$2, c$3) {
       bb7: if (c$3) break;
     }
   }
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/conditional-on-mutable.expect.md b/compiler/forget/src/__tests__/fixtures/hir/conditional-on-mutable.expect.md
index 139ba43615..16201e6521 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/conditional-on-mutable.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/conditional-on-mutable.expect.md
@@ -260,9 +260,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function Foo$0() {
-  return;
-}
+function Foo$0() {}
 
 ```
 ## HIR
@@ -288,9 +286,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function mayMutate$0() {
-  return;
-}
+function mayMutate$0() {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/constructor.expect.md b/compiler/forget/src/__tests__/fixtures/hir/constructor.expect.md
index 41488368b6..7da105640c 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/constructor.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/constructor.expect.md
@@ -38,9 +38,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function Foo$0() {
-  return;
-}
+function Foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/frozen-after-alias.expect.md b/compiler/forget/src/__tests__/fixtures/hir/frozen-after-alias.expect.md
index 0bf2f38fb3..d4d93d7a9a 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/frozen-after-alias.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/frozen-after-alias.expect.md
@@ -52,7 +52,6 @@ function Component$0() {
   const b$2 = a$1;
   useFreeze$3(a$1);
   foo$4(b$2);
-  return;
 }
 
 ```
@@ -79,9 +78,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function useFreeze$0() {
-  return;
-}
+function useFreeze$0() {}
 
 ```
 ## HIR
@@ -107,9 +104,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0(x$1) {
-  return;
-}
+function foo$0(x$1) {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/hook-call.expect.md b/compiler/forget/src/__tests__/fixtures/hir/hook-call.expect.md
index 1715e03f4d..2eea852daa 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/hook-call.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/hook-call.expect.md
@@ -42,9 +42,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function useFreeze$0() {
-  return;
-}
+function useFreeze$0() {}
 
 ```
 ## HIR
@@ -70,9 +68,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-arguments.expect.md b/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-arguments.expect.md
index 130f0a8d47..6d6a58ce19 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-arguments.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-arguments.expect.md
@@ -80,9 +80,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function useFreeze$0(x$1) {
-  return;
-}
+function useFreeze$0(x$1) {}
 
 ```
 ## HIR
@@ -108,9 +106,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function call$0(x$1) {
-  return;
-}
+function call$0(x$1) {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-possibly-mutable-arguments.expect.md b/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-possibly-mutable-arguments.expect.md
index 60734056e4..992160d1d7 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-possibly-mutable-arguments.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/hooks-freeze-possibly-mutable-arguments.expect.md
@@ -132,9 +132,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function useFreeze$0(x$1) {
-  return;
-}
+function useFreeze$0(x$1) {}
 
 ```
 ## HIR
@@ -160,9 +158,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function call$0(x$1) {
-  return;
-}
+function call$0(x$1) {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/independent-across-if.expect.md b/compiler/forget/src/__tests__/fixtures/hir/independent-across-if.expect.md
index b34cf51a33..fa88734c00 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/independent-across-if.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/independent-across-if.expect.md
@@ -56,9 +56,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function compute$0() {
-  return;
-}
+function compute$0() {}
 
 ```
 ## HIR
@@ -84,9 +82,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function mutate$0() {
-  return;
-}
+function mutate$0() {}
 
 ```
 ## HIR
@@ -112,9 +108,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
@@ -140,9 +134,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function Foo$0() {
-  return;
-}
+function Foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/independent.expect.md b/compiler/forget/src/__tests__/fixtures/hir/independent.expect.md
index b4fdedcbdb..20c7e0e44a 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/independent.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/independent.expect.md
@@ -85,9 +85,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function compute$0() {
-  return;
-}
+function compute$0() {}
 
 ```
 ## HIR
@@ -113,9 +111,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
@@ -141,9 +137,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function Foo$0() {
-  return;
-}
+function Foo$0() {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/interdependent-across-if.expect.md b/compiler/forget/src/__tests__/fixtures/hir/interdependent-across-if.expect.md
index abe3c1b7b7..4a2792e746 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/interdependent-across-if.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/interdependent-across-if.expect.md
@@ -50,9 +50,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function compute$0() {
-  return;
-}
+function compute$0() {}
 
 ```
 ## HIR
@@ -78,9 +76,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
@@ -106,9 +102,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function Foo$0() {
-  return;
-}
+function Foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/interdependent.expect.md b/compiler/forget/src/__tests__/fixtures/hir/interdependent.expect.md
index 4e883e0572..d1cc6cf443 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/interdependent.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/interdependent.expect.md
@@ -88,9 +88,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function compute$0() {
-  return;
-}
+function compute$0() {}
 
 ```
 ## HIR
@@ -116,9 +114,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
@@ -144,9 +140,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function Foo$0() {
-  return;
-}
+function Foo$0() {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/inverted-if.expect.md b/compiler/forget/src/__tests__/fixtures/hir/inverted-if.expect.md
index aa970af6bf..e303679ebd 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/inverted-if.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/inverted-if.expect.md
@@ -75,8 +75,6 @@ function foo$0(a$1, b$2, c$3) {
       y$4.push(c$3);
     }
   }
-
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/logical-expression.expect.md b/compiler/forget/src/__tests__/fixtures/hir/logical-expression.expect.md
index 356059267c..ccb4ba8336 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/logical-expression.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/logical-expression.expect.md
@@ -244,9 +244,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function f$0() {
-  return;
-}
+function f$0() {}
 
 ```
 ## HIR
@@ -272,9 +270,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function g$0() {
-  return;
-}
+function g$0() {}
 
 ```
       
\ No newline at end of file
diff --git a/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-loops.expect.md b/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-loops.expect.md
index 4d9f18e4ac..e1dbd9ef47 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-loops.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-loops.expect.md
@@ -62,9 +62,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function mutate$0(x$1, y$2) {
-  return;
-}
+function mutate$0(x$1, y$2) {}
 
 ```
 ## HIR
@@ -90,9 +88,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function cond$0(x$1) {
-  return;
-}
+function cond$0(x$1) {}
 
 ```
 ## HIR
@@ -247,7 +243,6 @@ function Component$0(props$1) {
   }
 
   mutate$7(d$5, null);
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-with-aliasing.expect.md b/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-with-aliasing.expect.md
index 2b7ba17595..937bd96b22 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-with-aliasing.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/mutable-lifetime-with-aliasing.expect.md
@@ -58,9 +58,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function mutate$0(x$1, y$2) {
-  return;
-}
+function mutate$0(x$1, y$2) {}
 
 ```
 ## HIR
@@ -174,7 +172,6 @@ function Component$0(props$1) {
   }
 
   mutate$8(x$6, null);
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/mutable-liverange-loop.expect.md b/compiler/forget/src/__tests__/fixtures/hir/mutable-liverange-loop.expect.md
index 21f369429e..c206727389 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/mutable-liverange-loop.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/mutable-liverange-loop.expect.md
@@ -57,9 +57,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function mutate$0() {
-  return;
-}
+function mutate$0() {}
 
 ```
 ## HIR
@@ -85,9 +83,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function cond$0() {
-  return;
-}
+function cond$0() {}
 
 ```
 ## HIR
@@ -227,7 +223,6 @@ function Component$0(props$1) {
   }
 
   mutate$6(d$5, null);
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/reverse-postorder.expect.md b/compiler/forget/src/__tests__/fixtures/hir/reverse-postorder.expect.md
index 1472a45216..39b90ca8c3 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/reverse-postorder.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/reverse-postorder.expect.md
@@ -189,7 +189,6 @@ function Component$0(props$1) {
   }
 
   x$2;
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/simple-alias.expect.md b/compiler/forget/src/__tests__/fixtures/hir/simple-alias.expect.md
index fd7bf6164a..6bed65657f 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/simple-alias.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/simple-alias.expect.md
@@ -39,9 +39,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function mutate$0() {
-  return;
-}
+function mutate$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx-2.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx-2.expect.md
index 9aa475d850..ce426e8558 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx-2.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx-2.expect.md
@@ -41,9 +41,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx.expect.md
index d0e082fb0d..06a22d2994 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-call-jsx.expect.md
@@ -38,9 +38,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function foo$0() {
-  return;
-}
+function foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-multiple-if.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-multiple-if.expect.md
index ce6ba4d3e7..ed7ab64412 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-multiple-if.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-multiple-if.expect.md
@@ -110,7 +110,6 @@ function foo$0() {
   }
 
   y$2 = x$1;
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-single-if.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-single-if.expect.md
index d1e93fa453..b2a5a715df 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-single-if.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-complex-single-if.expect.md
@@ -78,7 +78,6 @@ function foo$0() {
   }
 
   y$2 = x$1;
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-if-else.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-if-else.expect.md
index fef0f6a90a..cf44b88daf 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-if-else.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-if-else.expect.md
@@ -83,8 +83,6 @@ function foo$0() {
   } else {
     let z$4 = x$1;
   }
-
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-newexpression.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-newexpression.expect.md
index 60a8a93034..92bbd7cb78 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-newexpression.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-newexpression.expect.md
@@ -36,9 +36,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function Foo$0() {
-  return;
-}
+function Foo$0() {}
 
 ```
 ## HIR
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-shadowing.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-shadowing.expect.md
index 2dc0a98a9c..4ba6b0ae46 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-shadowing.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-shadowing.expect.md
@@ -40,9 +40,7 @@ flowchart TB
 ## Code
 
 ```javascript
-function log$0() {
-  return;
-}
+function log$0() {}
 
 ```
 ## HIR
@@ -119,7 +117,6 @@ function Foo$0(cond$1) {
   }
 
   log$4(str$2);
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-simple-phi.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-simple-phi.expect.md
index e260f6aa7f..0b7e5ac4af 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-simple-phi.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-simple-phi.expect.md
@@ -91,7 +91,6 @@ function foo$0() {
   }
 
   let x$4 = y$1;
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-simple.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-simple.expect.md
index 8c4774e683..d5c547125f 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-simple.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-simple.expect.md
@@ -41,7 +41,6 @@ flowchart TB
 function foo$0() {
   let x$1 = 1;
   let y$2 = 2;
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-single-if.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-single-if.expect.md
index 690151d5cb..ba0b3f3ab6 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-single-if.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-single-if.expect.md
@@ -67,8 +67,6 @@ function foo$0() {
   bb1: if (y$2) {
     let z$3 = x$1 + y$2;
   }
-
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/ssa-switch.expect.md b/compiler/forget/src/__tests__/fixtures/hir/ssa-switch.expect.md
index 1a8807f923..9cc3460938 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/ssa-switch.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/ssa-switch.expect.md
@@ -134,7 +134,6 @@ function foo$0() {
   }
 
   let y$9 = x$1;
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/switch-with-fallthrough.expect.md b/compiler/forget/src/__tests__/fixtures/hir/switch-with-fallthrough.expect.md
index 91c3e8ef0e..4406f18d32 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/switch-with-fallthrough.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/switch-with-fallthrough.expect.md
@@ -191,8 +191,6 @@ function foo$0(x$1) {
       y$2 = 0;
     }
   }
-
-  return;
 }
 
 ```
diff --git a/compiler/forget/src/__tests__/fixtures/hir/while-conditional-continue.expect.md b/compiler/forget/src/__tests__/fixtures/hir/while-conditional-continue.expect.md
index 94abf9e763..411b043133 100644
--- a/compiler/forget/src/__tests__/fixtures/hir/while-conditional-continue.expect.md
+++ b/compiler/forget/src/__tests__/fixtures/hir/while-conditional-continue.expect.md
@@ -94,7 +94,6 @@ function foo$0(a$1, b$2, c$3, d$4) {
   }
 
   d$4();
-  return;
 }
 
 ```