Omit asserts if condition can be proven statically (AssemblyScript#685)

Author: dcodeIO

src/builtins.ts

@@ -2090,6 +2090,52 @@ export function compileCall(
       let type = compiler.currentType;
       compiler.currentType = type.nonNullableType;
 
+      // if the assertion can be proven statically, omit it
+      if (getExpressionId(arg0 = module.precomputeExpression(arg0)) == ExpressionId.Const) {
+        switch (getExpressionType(arg0)) {
+          case NativeType.I32: {
+            if (getConstValueI32(arg0) != 0) {
+              if (contextualType == Type.void) {
+                compiler.currentType = Type.void;
+                return module.nop();
+              }
+              return arg0;
+            }
+            break;
+          }
+          case NativeType.I64: {
+            if (getConstValueI64Low(arg0) != 0 || getConstValueI64High(arg0) != 0) {
+              if (contextualType == Type.void) {
+                compiler.currentType = Type.void;
+                return module.nop();
+              }
+              return arg0;
+            }
+            break;
+          }
+          case NativeType.F32: {
+            if (getConstValueF32(arg0) != 0) {
+              if (contextualType == Type.void) {
+                compiler.currentType = Type.void;
+                return module.nop();
+              }
+              return arg0;
+            }
+            break;
+          }
+          case NativeType.F64: {
+            if (getConstValueF64(arg0) != 0) {
+              if (contextualType == Type.void) {
+                compiler.currentType = Type.void;
+                return module.nop();
+              }
+              return arg0;
+            }
+            break;
+          }
+        }
+      }
+
       // return ifTrueish if assertions are disabled
       if (compiler.options.noAssert) {
         if (contextualType == Type.void) { // simplify if dropped anyway

tests/compiler/assert.optimized.wat

@@ -1,10 +1,8 @@
 (module
  (type $FUNCSIG$v (func))
- (memory $0 1)
- (data (i32.const 8) "\12\00\00\00\01\00\00\00\01\00\00\00\12\00\00\00a\00s\00s\00e\00r\00t\00.\00t\00s")
- (data (i32.const 48) "\18\00\00\00\01\00\00\00\01\00\00\00\18\00\00\00m\00u\00s\00t\00 \00b\00e\00 \00t\00r\00u\00e")
+ (memory $0 0)
  (export "memory" (memory $0))
- (func $start (; 0 ;) (type $FUNCSIG$v)
+ (func $null (; 0 ;) (type $FUNCSIG$v)
   nop
  )
 )

tests/compiler/assert.untouched.wat

@@ -1,113 +1,9 @@
 (module
- (type $FUNCSIG$viiii (func (param i32 i32 i32 i32)))
  (type $FUNCSIG$v (func))
- (import "env" "abort" (func $~lib/builtins/abort (param i32 i32 i32 i32)))
- (memory $0 1)
- (data (i32.const 8) "\12\00\00\00\01\00\00\00\01\00\00\00\12\00\00\00a\00s\00s\00e\00r\00t\00.\00t\00s\00")
- (data (i32.const 48) "\18\00\00\00\01\00\00\00\01\00\00\00\18\00\00\00m\00u\00s\00t\00 \00b\00e\00 \00t\00r\00u\00e\00")
+ (memory $0 0)
  (table $0 1 funcref)
  (elem (i32.const 0) $null)
  (export "memory" (memory $0))
- (start $start)
- (func $start:assert (; 1 ;) (type $FUNCSIG$v)
-  (local $0 i32)
-  i32.const 1
-  i32.eqz
-  if
-   i32.const 0
-   i32.const 24
-   i32.const 1
-   i32.const 0
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i32.const 1
-  i32.eqz
-  if
-   i32.const 0
-   i32.const 24
-   i32.const 2
-   i32.const 0
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i32.const 1
-  i32.const 0
-  i32.gt_u
-  i32.eqz
-  if
-   i32.const 0
-   i32.const 24
-   i32.const 3
-   i32.const 0
-   call $~lib/builtins/abort
-   unreachable
-  end
-  f64.const 0.5
-  f64.const 0
-  f64.eq
-  if
-   i32.const 0
-   i32.const 24
-   i32.const 4
-   i32.const 0
-   call $~lib/builtins/abort
-   unreachable
-  end
-  f64.const 0.5
-  f64.const 0.4
-  f64.gt
-  i32.eqz
-  if
-   i32.const 0
-   i32.const 24
-   i32.const 5
-   i32.const 0
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i64.const 4294967296
-  i64.eqz
-  if
-   i32.const 0
-   i32.const 24
-   i32.const 6
-   i32.const 0
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i64.const 4294967296
-  i64.const 1
-  i64.gt_s
-  i32.eqz
-  if
-   i32.const 0
-   i32.const 24
-   i32.const 7
-   i32.const 0
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i32.const 1
-  local.tee $0
-  if (result i32)
-   local.get $0
-  else   
-   i32.const 64
-   i32.const 24
-   i32.const 10
-   i32.const 5
-   call $~lib/builtins/abort
-   unreachable
-  end
-  i32.eqz
-  if
-   unreachable
-  end
- )
- (func $start (; 2 ;) (type $FUNCSIG$v)
-  call $start:assert
- )
- (func $null (; 3 ;) (type $FUNCSIG$v)
+ (func $null (; 0 ;) (type $FUNCSIG$v)
  )
 )