Implement ternary using if, see AssemblyScript/assemblyscript#123

assembly.d.ts

@@ -66,7 +66,7 @@ declare function current_memory(): i32;
 /** Grows linear memory by a given unsigned delta of pages. One page is 64kb. Returns the previous memory size in units of pages or `-1` on failure. */
 declare function grow_memory(value: i32): i32;
 /** Emits an unreachable operation that results in a runtime error when executed. */
-declare function unreachable(): void;
+declare function unreachable(): any; // sic
 
 /** Loads a value of the specified type from memory. */
 declare function load<T>(offset: usize): T;

bin/asc.json

@@ -8,5 +8,14 @@
     "desc": "Print this message.",
     "type": "boolean",
     "aliases": [ "h" ]
+  },
+  "optimize": {
+    "desc": "Optimize the module.",
+    "type": "boolean",
+    "aliases": [ "O" ]
+  },
+  "validate": {
+    "desc": "Validate the module.",
+    "type": "boolean"
   }
 }

bin/asc.ts

@@ -8,6 +8,7 @@ import * as as from "../src";
 
 var conf: { [key: string]: { desc: string, type: string, aliases: string[], default: any } } = require("./asc.json");
 var opts: minimist.Opts = {};
+
 Object.keys(conf).forEach(key => {
   var opt = conf[key];
   if (opt.aliases)
@@ -80,7 +81,7 @@ let diagnostic: as.DiagnosticMessage | null;
 let hasErrors: boolean = false;
 
 while ((diagnostic = as.nextDiagnostic(parser)) != null) {
-  console.error(as.formatDiagnostic(diagnostic, process.stdout.isTTY, true));
+  console.error(as.formatDiagnostic(diagnostic, process.stderr.isTTY, true));
   if (as.isError(diagnostic))
     hasErrors = true;
 }
@@ -89,5 +90,27 @@ if (hasErrors)
   process.exit(1);
 
 const module = as.compile(parser);
+
+hasErrors = false;
+while ((diagnostic = as.nextDiagnostic(parser)) != null) {
+  console.error(as.formatDiagnostic(diagnostic, process.stderr.isTTY, true));
+  if (as.isError(diagnostic))
+    hasErrors = true;
+}
+
+if (hasErrors) {
+  module.dispose();
+  process.exit(1);
+}
+
+if (args["validate"])
+  if (!module.validate()) {
+    module.dispose();
+    process.exit(1);
+  }
+
+if (args["optimize"])
+  module.optimize();
+
 _BinaryenModulePrint(module.ref);
 module.dispose();

src/ast.ts

@@ -19,7 +19,7 @@
  │ ├ ParenthesizedExpression
  │ ├ NewExpression
  │ ├ PropertyAccessExpression
- │ ├ SelectExpression
+ │ ├ TernaryExpression
  │ └ UnaryExpression
  │   ├ UnaryPostfixExpression
  │   └ UnaryPrefixExpression
@@ -101,7 +101,7 @@ export enum NodeKind {
   NULL,
   PARENTHESIZED,
   PROPERTYACCESS,
-  SELECT,
+  TERNARY,
   SUPER,
   THIS,
   TRUE,
@@ -302,8 +302,8 @@ export abstract class Expression extends Node {
     return expr;
   }
 
-  static createSelect(condition: Expression, ifThen: Expression, ifElse: Expression, range: Range): SelectExpression {
-    const expr: SelectExpression = new SelectExpression();
+  static createTernary(condition: Expression, ifThen: Expression, ifElse: Expression, range: Range): TernaryExpression {
+    const expr: TernaryExpression = new TernaryExpression();
     expr.range = range;
     (expr.condition = condition).parent = expr;
     (expr.ifThen = ifThen).parent = expr;
@@ -549,9 +549,9 @@ export class RegexpLiteralExpression extends LiteralExpression {
   }
 }
 
-export class SelectExpression extends Expression {
+export class TernaryExpression extends Expression {
 
-  kind = NodeKind.SELECT;
+  kind = NodeKind.TERNARY;
   condition: Expression;
   ifThen: Expression;
   ifElse: Expression;

src/compiler.ts

@@ -59,7 +59,7 @@ import {
   NewExpression,
   ParenthesizedExpression,
   PropertyAccessExpression,
-  SelectExpression,
+  TernaryExpression,
   StringLiteralExpression,
   UnaryPostfixExpression,
   UnaryPrefixExpression,
@@ -927,8 +927,8 @@ export class Compiler extends DiagnosticEmitter {
         expr = this.compilePropertyAccessExpression(<PropertyAccessExpression>expression, contextualType);
         break;
 
-      case NodeKind.SELECT:
-        expr = this.compileSelectExpression(<SelectExpression>expression, contextualType);
+      case NodeKind.TERNARY:
+        expr = this.compileTernaryExpression(<TernaryExpression>expression, contextualType);
         break;
 
       case NodeKind.UNARYPOSTFIX:
@@ -1482,6 +1482,7 @@ export class Compiler extends DiagnosticEmitter {
 
   /** Compiles a call to a function. If an instance method, `this` is the first element in `argumentExpressions`. */
   compileCall(functionInstance: Function, argumentExpressions: Expression[], reportNode: Node): ExpressionRef {
+    const previousType: Type = this.currentType;
 
     // validate and compile arguments
     const parameters: Parameter[] = functionInstance.parameters;
@@ -1627,6 +1628,7 @@ export class Compiler extends DiagnosticEmitter {
           return this.module.createHost(HostOp.GrowMemory, null, operands);
 
         case "unreachable":
+          this.currentType = previousType;
           return this.module.createUnreachable();
 
         case "isNaN": // value != value
@@ -1645,35 +1647,35 @@ export class Compiler extends DiagnosticEmitter {
           }
           break;
 
-        case "isFinite": // value != value ? false : abs(value) != Infinity
+        case "isFinite": // v=[abs(value) != Infinity, false]; return value == value ? v[0] : v[1]
           if (functionInstance.typeArguments[0] == Type.f64) {
             tempLocal = this.currentFunction.addLocal(Type.f64);
             return this.module.createSelect(
-              this.module.createBinary(BinaryOp.NeF64,
-                this.module.createTeeLocal(tempLocal.index, operands[0]),
-                this.module.createGetLocal(tempLocal.index, NativeType.F64)
-              ),
-              this.module.createI32(0),
               this.module.createBinary(BinaryOp.NeF64,
                 this.module.createUnary(UnaryOp.AbsF64,
-                  this.module.createGetLocal(tempLocal.index, NativeType.F64)
+                  this.module.createTeeLocal(tempLocal.index, operands[0])
                 ),
                 this.module.createF64(Infinity)
+              ),
+              this.module.createI32(0),
+              this.module.createBinary(BinaryOp.EqF64,
+                this.module.createGetLocal(tempLocal.index, NativeType.F64),
+                this.module.createGetLocal(tempLocal.index, NativeType.F64)
               )
             );
           } else if (functionInstance.typeArguments[0] == Type.f32) {
             tempLocal = this.currentFunction.addLocal(Type.f32);
             return this.module.createSelect(
-              this.module.createBinary(BinaryOp.NeF32,
-                this.module.createTeeLocal(tempLocal.index, operands[0]),
-                this.module.createGetLocal(tempLocal.index, NativeType.F32)
-              ),
-              this.module.createI32(0),
               this.module.createBinary(BinaryOp.NeF32,
                 this.module.createUnary(UnaryOp.AbsF32,
-                  this.module.createGetLocal(tempLocal.index, NativeType.F32)
+                  this.module.createTeeLocal(tempLocal.index, operands[0])
                 ),
                 this.module.createF32(Infinity)
+              ),
+              this.module.createI32(0),
+              this.module.createBinary(BinaryOp.EqF32,
+                this.module.createGetLocal(tempLocal.index, NativeType.F32),
+                this.module.createGetLocal(tempLocal.index, NativeType.F32)
               )
             );
           }
@@ -1845,11 +1847,11 @@ export class Compiler extends DiagnosticEmitter {
     throw new Error("not implemented");
   }
 
-  compileSelectExpression(expression: SelectExpression, contextualType: Type): ExpressionRef {
+  compileTernaryExpression(expression: TernaryExpression, contextualType: Type): ExpressionRef {
     const condition: ExpressionRef = this.compileExpression(expression.condition, Type.i32);
     const ifThen: ExpressionRef = this.compileExpression(expression.ifThen, contextualType);
     const ifElse: ExpressionRef = this.compileExpression(expression.ifElse, contextualType);
-    return this.module.createSelect(condition, ifThen, ifElse);
+    return this.module.createIf(condition, ifThen, ifElse);
   }
 
   compileUnaryPostfixExpression(expression: UnaryPostfixExpression, contextualType: Type): ExpressionRef {

src/module.ts

@@ -448,7 +448,7 @@ export class Module {
     return _BinaryenReturn(this.ref, expression);
   }
 
-  createSelect(condition: ExpressionRef, ifTrue: ExpressionRef, ifFalse: ExpressionRef): ExpressionRef {
+  createSelect(ifTrue: ExpressionRef, ifFalse: ExpressionRef, condition: ExpressionRef): ExpressionRef {
     if (this.noEmit) return 0;
     return _BinaryenSelect(this.ref, condition, ifTrue, ifFalse);
   }

src/parser.ts

@@ -1456,7 +1456,7 @@ export class Parser extends DiagnosticEmitter {
           this.error(DiagnosticCode.The_operand_of_an_increment_or_decrement_operator_must_be_a_variable_or_a_property_access, expr.range);
         expr = Expression.createUnaryPostfix(token, expr, tn.range(startPos, tn.pos));
 
-      // SelectExpression
+      // TernaryExpression
       } else if (token == Token.QUESTION) {
         const ifThen: Expression | null = this.parseExpression(tn);
         if (!ifThen)
@@ -1465,7 +1465,7 @@ export class Parser extends DiagnosticEmitter {
           const ifElse: Expression | null = this.parseExpression(tn);
           if (!ifElse)
             return null;
-          expr = Expression.createSelect(<Expression>expr, <Expression>ifThen, <Expression>ifElse, tn.range(startPos, tn.pos));
+          expr = Expression.createTernary(<Expression>expr, <Expression>ifThen, <Expression>ifElse, tn.range(startPos, tn.pos));
         } else {
           this.error(DiagnosticCode._0_expected, tn.range(), ":");
           return null;

tests/compiler/builtins.ts

@@ -121,3 +121,14 @@ sizeof<f64>();
 
 i = load<i32>(4);
 store<i32>(4, i);
+
+if (NaN == NaN)
+  unreachable();
+if (!isNaN<f32>(NaN))
+  unreachable();
+if (isFinite<f32>(NaN))
+  unreachable();
+if (isFinite<f32>(Infinity))
+  unreachable();
+if (!isFinite<f64>(0))
+  unreachable();

tests/compiler/builtins.wast

@@ -19,6 +19,10 @@
   (local $5 f64)
   (local $6 f64)
   (local $7 f64)
+  (local $8 f32)
+  (local $9 f32)
+  (local $10 f32)
+  (local $11 f64)
   (drop
    (i32.clz
     (i32.const 1)
@@ -191,17 +195,17 @@
   )
   (drop
    (select
-    (i32.const 0)
     (f32.ne
      (f32.abs
-      (get_local $1)
-     )
-     (f32.const inf)
-    )
-    (f32.ne
       (tee_local $1
        (f32.const 1.25)
       )
+     )
+     (f32.const inf)
+    )
+    (i32.const 0)
+    (f32.eq
+     (get_local $1)
      (get_local $1)
     )
    )
@@ -270,17 +274,17 @@
   )
   (set_global $builtins/b
    (select
-    (i32.const 0)
     (f32.ne
      (f32.abs
-      (get_local $3)
-     )
-     (f32.const inf)
-    )
-    (f32.ne
       (tee_local $3
        (f32.const 1.25)
       )
+     )
+     (f32.const inf)
+    )
+    (i32.const 0)
+    (f32.eq
+     (get_local $3)
      (get_local $3)
     )
    )
@@ -355,17 +359,17 @@
   )
   (drop
    (select
-    (i32.const 0)
     (f64.ne
      (f64.abs
-      (get_local $5)
-     )
-     (f64.const inf)
-    )
-    (f64.ne
       (tee_local $5
        (f64.const 1.25)
       )
+     )
+     (f64.const inf)
+    )
+    (i32.const 0)
+    (f64.eq
+     (get_local $5)
      (get_local $5)
     )
    )
@@ -434,17 +438,17 @@
   )
   (set_global $builtins/b
    (select
-    (i32.const 0)
     (f64.ne
      (f64.abs
-      (get_local $7)
-     )
-     (f64.const inf)
-    )
-    (f64.ne
       (tee_local $7
        (f64.const 1.25)
       )
+     )
+     (f64.const inf)
+    )
+    (i32.const 0)
+    (f64.eq
+     (get_local $7)
      (get_local $7)
     )
    )
@@ -523,6 +527,80 @@
    (i32.const 4)
    (get_global $builtins/i)
   )
+  (if
+   (f64.eq
+    (f64.const nan:0x8000000000000)
+    (f64.const nan:0x8000000000000)
+   )
+   (unreachable)
+  )
+  (if
+   (i32.eqz
+    (f32.ne
+     (tee_local $8
+      (f32.const nan:0x400000)
+     )
+     (get_local $8)
+    )
+   )
+   (unreachable)
+  )
+  (if
+   (select
+    (f32.ne
+     (f32.abs
+      (tee_local $9
+       (f32.const nan:0x400000)
+      )
+     )
+     (f32.const inf)
+    )
+    (i32.const 0)
+    (f32.eq
+     (get_local $9)
+     (get_local $9)
+    )
+   )
+   (unreachable)
+  )
+  (if
+   (select
+    (f32.ne
+     (f32.abs
+      (tee_local $10
+       (f32.const inf)
+      )
+     )
+     (f32.const inf)
+    )
+    (i32.const 0)
+    (f32.eq
+     (get_local $10)
+     (get_local $10)
+    )
+   )
+   (unreachable)
+  )
+  (if
+   (i32.eqz
+    (select
+     (f64.ne
+      (f64.abs
+       (tee_local $11
+        (f64.const 0)
+       )
+      )
+      (f64.const inf)
+     )
+     (i32.const 0)
+     (f64.eq
+      (get_local $11)
+      (get_local $11)
+     )
+    )
+   )
+   (unreachable)
+  )
  )
 )
 (;

tests/compiler/ternary.ts

@@ -0,0 +1,5 @@
+let a: i32;
+
+a = 0 ? unreachable() : 1;
+a = 1 ? 1 : unreachable();
+a = (0 ? unreachable() : 1) ? 1 : unreachable();

tests/compiler/ternary.wast

@@ -0,0 +1,64 @@
+(module
+ (type $v (func))
+ (global $ternary/a (mut i32) (i32.const 0))
+ (memory $0 1)
+ (data (i32.const 4) "\08\00\00\00")
+ (export "memory" (memory $0))
+ (start $start)
+ (func $start (; 0 ;) (type $v)
+  (set_global $ternary/a
+   (if (result i32)
+    (i32.const 0)
+    (unreachable)
+    (i32.const 1)
+   )
+  )
+  (set_global $ternary/a
+   (if (result i32)
+    (i32.const 1)
+    (i32.const 1)
+    (unreachable)
+   )
+  )
+  (set_global $ternary/a
+   (if (result i32)
+    (if (result i32)
+     (i32.const 0)
+     (unreachable)
+     (i32.const 1)
+    )
+    (i32.const 1)
+    (unreachable)
+   )
+  )
+ )
+)
+(;
+[program.elements]
+  clz
+  ctz
+  popcnt
+  rotl
+  rotr
+  abs
+  ceil
+  copysign
+  floor
+  max
+  min
+  nearest
+  sqrt
+  trunc
+  current_memory
+  grow_memory
+  unreachable
+  isNaN
+  isFinite
+  assert
+  sizeof
+  load
+  store
+  ternary/a
+[program.exports]
+  
+;)