encoding/ieee754: rewrite using typedarray

compiler/encoding.js

@@ -105,119 +105,5 @@ export const read_unsignedLEB128 = _input => {
 };
 
 // ieee 754 binary64
-
-// from https://github.com/feross/ieee754
-// BSD 3-Clause. Copyright 2008 Fair Oaks Labs, Inc. (https://github.com/feross/ieee754/blob/master/LICENSE)
-export const ieee754_binary64 = value => {
-  return [...new Uint8Array(new Float64Array([ value ]).buffer)];
-
-  let isLE = true, mLen = 52, nBytes = 8, offset = 0;
-  let buffer = new Array(nBytes).fill(0);
-
-  let e, m, c
-  let eLen = (nBytes * 8) - mLen - 1
-  const eMax = (1 << eLen) - 1
-  const eBias = eMax >> 1
-  const rt = (mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0)
-  let i = isLE ? 0 : (nBytes - 1)
-  const d = isLE ? 1 : -1
-  const s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0
-
-  value = Math.abs(value)
-
-  if (isNaN(value) || value === Infinity) {
-    m = isNaN(value) ? 1 : 0
-    e = eMax
-  } else {
-    e = Math.floor(Math.log(value) / Math.LN2)
-    if (value * (c = Math.pow(2, -e)) < 1) {
-      e--
-      c *= 2
-    }
-    if (e + eBias >= 1) {
-      value += rt / c
-    } else {
-      value += rt * Math.pow(2, 1 - eBias)
-    }
-    if (value * c >= 2) {
-      e++
-      c /= 2
-    }
-
-    if (e + eBias >= eMax) {
-      m = 0
-      e = eMax
-    } else if (e + eBias >= 1) {
-      m = ((value * c) - 1) * Math.pow(2, mLen)
-      e = e + eBias
-    } else {
-      m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen)
-      e = 0
-    }
-  }
-
-  while (mLen >= 8) {
-    buffer[offset + i] = m & 0xff
-    i += d
-    m /= 256
-    mLen -= 8
-  }
-
-  e = (e << mLen) | m
-  eLen += mLen
-  while (eLen > 0) {
-    buffer[offset + i] = e & 0xff
-    i += d
-    e /= 256
-    eLen -= 8
-  }
-
-  buffer[offset + i - d] |= s * 128
-
-  return buffer;
-};
-
-export const read_ieee754_binary64 = buffer => {
-  return new Float64Array(new Uint8Array(buffer).buffer)[0];
-
-  let isLE = true, mLen = 52, nBytes = 8, offset = 0;
-
-  let e, m
-  const eLen = (nBytes * 8) - mLen - 1
-  const eMax = (1 << eLen) - 1
-  const eBias = eMax >> 1
-  let nBits = -7
-  let i = isLE ? (nBytes - 1) : 0
-  const d = isLE ? -1 : 1
-  let s = buffer[offset + i]
-
-  i += d
-
-  e = s & ((1 << (-nBits)) - 1)
-  s >>= (-nBits)
-  nBits += eLen
-  while (nBits > 0) {
-    e = (e * 256) + buffer[offset + i]
-    i += d
-    nBits -= 8
-  }
-
-  m = e & ((1 << (-nBits)) - 1)
-  e >>= (-nBits)
-  nBits += mLen
-  while (nBits > 0) {
-    m = (m * 256) + buffer[offset + i]
-    i += d
-    nBits -= 8
-  }
-
-  if (e === 0) {
-    e = 1 - eBias
-  } else if (e === eMax) {
-    return m ? NaN : ((s ? -1 : 1) * Infinity)
-  } else {
-    m = m + Math.pow(2, mLen)
-    e = e - eBias
-  }
-  return (s ? -1 : 1) * m * Math.pow(2, e - mLen)
-};
+export const ieee754_binary64 = value => [...new Uint8Array(new Float64Array([ value ]).buffer)];
+export const read_ieee754_binary64 = buffer => new Float64Array(new Uint8Array(buffer).buffer)[0];