util: simplify SIMD setup

PR-URL: nodejs#8579
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ilkka Myller <ilkka.myller@nodefield.com>

lib/util.js

@@ -38,35 +38,23 @@ if (typeof global.SIMD === 'object' && global.SIMD !== null) {
 
   const SIMD = global.SIMD;  // Pacify eslint.
 
-  if (typeof SIMD.Bool16x8 === 'function')
-    simdFormatters.set(SIMD.Bool16x8, make(SIMD.Bool16x8.extractLane, 8));
-
-  if (typeof SIMD.Bool32x4 === 'function')
-    simdFormatters.set(SIMD.Bool32x4, make(SIMD.Bool32x4.extractLane, 4));
-
-  if (typeof SIMD.Bool8x16 === 'function')
-    simdFormatters.set(SIMD.Bool8x16, make(SIMD.Bool8x16.extractLane, 16));
-
-  if (typeof SIMD.Float32x4 === 'function')
-    simdFormatters.set(SIMD.Float32x4, make(SIMD.Float32x4.extractLane, 4));
-
-  if (typeof SIMD.Int16x8 === 'function')
-    simdFormatters.set(SIMD.Int16x8, make(SIMD.Int16x8.extractLane, 8));
-
-  if (typeof SIMD.Int32x4 === 'function')
-    simdFormatters.set(SIMD.Int32x4, make(SIMD.Int32x4.extractLane, 4));
-
-  if (typeof SIMD.Int8x16 === 'function')
-    simdFormatters.set(SIMD.Int8x16, make(SIMD.Int8x16.extractLane, 16));
-
-  if (typeof SIMD.Uint16x8 === 'function')
-    simdFormatters.set(SIMD.Uint16x8, make(SIMD.Uint16x8.extractLane, 8));
-
-  if (typeof SIMD.Uint32x4 === 'function')
-    simdFormatters.set(SIMD.Uint32x4, make(SIMD.Uint32x4.extractLane, 4));
+  const countPerType = {
+    Bool16x8: 8,
+    Bool32x4: 4,
+    Bool8x16: 16,
+    Float32x4: 4,
+    Int16x8: 8,
+    Int32x4: 4,
+    Int8x16: 16,
+    Uint16x8: 8,
+    Uint32x4: 4,
+    Uint8x16: 16
+  };
 
-  if (typeof SIMD.Uint8x16 === 'function')
-    simdFormatters.set(SIMD.Uint8x16, make(SIMD.Uint8x16.extractLane, 16));
+  for (const key in countPerType) {
+    const type = SIMD[key];
+    simdFormatters.set(type, make(type.extractLane, countPerType[key]));
+  }
 }
 
 function tryStringify(arg) {