fix: wrap small integers before casting them to bool

NOTICE

@@ -63,6 +63,7 @@ under the licensing terms detailed in LICENSE:
 * Mopsgamer <79159094+Mopsgamer@users.noreply.github.com>
 * EDM115 <github@edm115.dev>
 * Weixie Cui <cuiweixie@gmail.com>
+* Swastik Tripathi <swastiktripathi.space@gmail.com>
 
 Portions of this software are derived from third-party works licensed under
 the following terms:

src/compiler.ts

@@ -3802,8 +3802,8 @@ export class Compiler extends DiagnosticEmitter {
       } else {
         // small i32 to ...
         if (fromType.isShortIntegerValue) {
-          // small i32 to larger i32
-          if (fromType.size < toType.size) {
+          // small i32 to larger i32, or to bool, which tests all 32 bits
+          if (fromType.size < toType.size || toType.isBooleanValue) {
             expr = this.ensureSmallIntegerWrap(expr, fromType); // must clear garbage bits
           }
         // same size

tests/compiler/bool.debug.wat

@@ -1,6 +1,7 @@
 (module
- (type $0 (func))
- (type $1 (func (param i32 i32 i32 i32)))
+ (type $0 (func (param i32) (result i32)))
+ (type $1 (func))
+ (type $2 (func (param i32 i32 i32 i32)))
  (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
  (global $bool/i (mut i32) (i32.const 2))
  (global $bool/I (mut i64) (i64.const 2))
@@ -50,6 +51,48 @@
  (elem $0 (i32.const 1))
  (export "memory" (memory $0))
  (start $~start)
+ (func $bool/u8PlusOne (param $a i32) (result i32)
+  (local $c i32)
+  local.get $a
+  i32.const 1
+  i32.add
+  local.set $c
+  local.get $c
+  i32.const 255
+  i32.and
+  return
+ )
+ (func $bool/i8PlusOne (param $a i32) (result i32)
+  (local $c i32)
+  local.get $a
+  i32.const 1
+  i32.add
+  local.set $c
+  local.get $c
+  i32.extend8_s
+  return
+ )
+ (func $bool/u16PlusOne (param $a i32) (result i32)
+  (local $c i32)
+  local.get $a
+  i32.const 1
+  i32.add
+  local.set $c
+  local.get $c
+  i32.const 65535
+  i32.and
+  return
+ )
+ (func $bool/i16PlusOne (param $a i32) (result i32)
+  (local $c i32)
+  local.get $a
+  i32.const 1
+  i32.add
+  local.set $c
+  local.get $c
+  i32.extend16_s
+  return
+ )
  (func $start:bool
   global.get $bool/i
   i32.const 0
@@ -759,6 +802,96 @@
    call $~lib/builtins/abort
    unreachable
   end
+  i32.const 255
+  call $bool/u8PlusOne
+  i32.const 0
+  i32.ne
+  i32.const 0
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 80
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 0
+  call $bool/u8PlusOne
+  i32.const 0
+  i32.ne
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 81
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const -1
+  call $bool/i8PlusOne
+  i32.const 0
+  i32.ne
+  i32.const 0
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 86
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 127
+  call $bool/i8PlusOne
+  i32.const 0
+  i32.ne
+  i32.const 1
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 87
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const 65535
+  call $bool/u16PlusOne
+  i32.const 0
+  i32.ne
+  i32.const 0
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 92
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
+  i32.const -1
+  call $bool/i16PlusOne
+  i32.const 0
+  i32.ne
+  i32.const 0
+  i32.eq
+  i32.eqz
+  if
+   i32.const 0
+   i32.const 32
+   i32.const 97
+   i32.const 1
+   call $~lib/builtins/abort
+   unreachable
+  end
  )
  (func $~start
   call $start:bool

tests/compiler/bool.ts

@@ -71,3 +71,27 @@ assert(<bool>F13 == false);
 
 var uu = <u8>2;
 assert(<bool>uu == true);
+
+// small integers are wrapped before testing them, so a value that overflowed to 0 is false
+function u8PlusOne(a: u8): bool {
+  let c: u8 = a + 1;
+  return <bool>c;
+}
+assert(u8PlusOne(255) == false);
+assert(u8PlusOne(0) == true);
+function i8PlusOne(a: i8): bool {
+  let c: i8 = a + 1;
+  return c as bool;
+}
+assert(i8PlusOne(-1) == false);
+assert(i8PlusOne(127) == true);
+function u16PlusOne(a: u16): bool {
+  let c: u16 = a + 1;
+  return bool(c);
+}
+assert(u16PlusOne(65535) == false);
+function i16PlusOne(a: i16): bool {
+  let c: i16 = a + 1;
+  return <bool>c;
+}
+assert(i16PlusOne(-1) == false);

tests/compiler/cast.debug.wat

@@ -79,6 +79,7 @@
  (func $"cast/test<i8,bool>" (param $x i32) (result i32)
   (local $y i32)
   local.get $x
+  i32.extend8_s
   local.set $y
   local.get $y
   return
@@ -156,6 +157,8 @@
  (func $"cast/test<u8,bool>" (param $x i32) (result i32)
   (local $y i32)
   local.get $x
+  i32.const 255
+  i32.and
   local.set $y
   local.get $y
   return
@@ -225,6 +228,7 @@
  (func $"cast/test<i16,bool>" (param $x i32) (result i32)
   (local $y i32)
   local.get $x
+  i32.extend16_s
   local.set $y
   local.get $y
   return
@@ -298,6 +302,8 @@
  (func $"cast/test<u16,bool>" (param $x i32) (result i32)
   (local $y i32)
   local.get $x
+  i32.const 65535
+  i32.and
   local.set $y
   local.get $y
   return