diff --git a/CHANGES.md b/CHANGES.md
index e8bb3a5698..6393730c3b 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -25,6 +25,7 @@
 * Lib: make the Wasm version of Json.output work with native ints and JavaScript objects (#1872)
 * Compiler: static evaluation of more primitives (#1912)
 * Compiler: faster compilation by stopping sooner when optimizations become unproductive (#1939)
+* Runtime: use Dataview to convert between floats and bit representation
 
 ## Bug fixes
 * Compiler: fix stack overflow issues with double translation (#1869)
diff --git a/ECMASCRIPT.md b/ECMASCRIPT.md
index 1aa48cfd82..839fce3b2b 100644
--- a/ECMASCRIPT.md
+++ b/ECMASCRIPT.md
@@ -56,6 +56,10 @@ Features are grouped by ECMAScript version.
 
 - [Compatibility](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/WeakMap#browser_compatibility)
 
+### DataView
+
+- [Compatibility](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/DataView#browser_compatibility)
+
 ## ECMAScript 2016
 
 ### async function
diff --git a/compiler/lib/reserved.ml b/compiler/lib/reserved.ml
index 05d0995917..fde3acd8fe 100644
--- a/compiler/lib/reserved.ml
+++ b/compiler/lib/reserved.ml
@@ -144,6 +144,7 @@ let provided =
     ; "require" (* only available in node *)
     ; "Symbol"
     ; "ArrayBuffer"
+    ; "DataView"
     ; "Float32Array"
     ; "Float64Array"
     ; "Int16Array"
diff --git a/compiler/tests-check-prim/main.4.14.output b/compiler/tests-check-prim/main.4.14.output
index dd380a2fa2..cbfefa3a6f 100644
--- a/compiler/tests-check-prim/main.4.14.output
+++ b/compiler/tests-check-prim/main.4.14.output
@@ -91,6 +91,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/main.5.2.output b/compiler/tests-check-prim/main.5.2.output
index f89beb7774..6aff797f81 100644
--- a/compiler/tests-check-prim/main.5.2.output
+++ b/compiler/tests-check-prim/main.5.2.output
@@ -87,6 +87,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/main.5.3.output b/compiler/tests-check-prim/main.5.3.output
index d2184637ac..471517932a 100644
--- a/compiler/tests-check-prim/main.5.3.output
+++ b/compiler/tests-check-prim/main.5.3.output
@@ -86,6 +86,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/unix-Unix.4.14.output b/compiler/tests-check-prim/unix-Unix.4.14.output
index e0ddc0dac5..c6bbcdf91f 100644
--- a/compiler/tests-check-prim/unix-Unix.4.14.output
+++ b/compiler/tests-check-prim/unix-Unix.4.14.output
@@ -167,6 +167,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/unix-Unix.5.2.output b/compiler/tests-check-prim/unix-Unix.5.2.output
index 1084d9a96f..6e1c8ba8e5 100644
--- a/compiler/tests-check-prim/unix-Unix.5.2.output
+++ b/compiler/tests-check-prim/unix-Unix.5.2.output
@@ -163,6 +163,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/unix-Unix.5.3.output b/compiler/tests-check-prim/unix-Unix.5.3.output
index c4a656b325..df95281669 100644
--- a/compiler/tests-check-prim/unix-Unix.5.3.output
+++ b/compiler/tests-check-prim/unix-Unix.5.3.output
@@ -162,6 +162,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/unix-Win32.4.14.output b/compiler/tests-check-prim/unix-Win32.4.14.output
index 2bc200a97d..dd90ad4b34 100644
--- a/compiler/tests-check-prim/unix-Win32.4.14.output
+++ b/compiler/tests-check-prim/unix-Win32.4.14.output
@@ -139,6 +139,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/unix-Win32.5.2.output b/compiler/tests-check-prim/unix-Win32.5.2.output
index 08d612f687..2cf4eaf5ac 100644
--- a/compiler/tests-check-prim/unix-Win32.5.2.output
+++ b/compiler/tests-check-prim/unix-Win32.5.2.output
@@ -136,6 +136,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/compiler/tests-check-prim/unix-Win32.5.3.output b/compiler/tests-check-prim/unix-Win32.5.3.output
index 7a05e69e21..8fc788cc78 100644
--- a/compiler/tests-check-prim/unix-Win32.5.3.output
+++ b/compiler/tests-check-prim/unix-Win32.5.3.output
@@ -135,6 +135,9 @@ caml_gr_text_size
 caml_gr_wait_event
 caml_gr_window_id
 
+From +hash.js:
+caml_hash_mix_int64
+
 From +ints.js:
 caml_div
 caml_mod
diff --git a/runtime/js/hash.js b/runtime/js/hash.js
index dcd9f9825f..ae19898dae 100644
--- a/runtime/js/hash.js
+++ b/runtime/js/hash.js
@@ -41,9 +41,26 @@ function caml_hash_mix_final(h) {
 }
 
 //Provides: caml_hash_mix_float
-//Requires: caml_int64_bits_of_float, caml_hash_mix_int64
-function caml_hash_mix_float(h, v0) {
-  return caml_hash_mix_int64(h, caml_int64_bits_of_float(v0));
+//Requires: caml_int64_bits_of_float
+//Requires: caml_hash_mix_int
+//Requires: caml_int64_lo32, caml_int64_hi32
+function caml_hash_mix_float(hash, v0) {
+  var i64 = caml_int64_bits_of_float(v0);
+  var l = caml_int64_lo32(i64);
+  var h = caml_int64_hi32(i64);
+  /* Normalize NaNs */
+  if ((h & 0x7ff00000) === 0x7ff00000 && (l | (h & 0xfffff)) !== 0) {
+    h = 0x7ff00000;
+    l = 0x00000001;
+  } else if (h === (0x80000000 | 0) && l === 0) {
+    /* Normalize -0 into +0 */
+    // This code path is not used by caml_hash because 0 and -0 look
+    // like integers
+    h = 0;
+  }
+  hash = caml_hash_mix_int(hash, l);
+  hash = caml_hash_mix_int(hash, h);
+  return hash;
 }
 //Provides: caml_hash_mix_int64
 //Requires: caml_hash_mix_int
diff --git a/runtime/js/ieee_754.js b/runtime/js/ieee_754.js
index 4a33608947..f0fc1cf124 100644
--- a/runtime/js/ieee_754.js
+++ b/runtime/js/ieee_754.js
@@ -17,74 +17,27 @@
 // along with this program; if not, write to the Free Software
 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 
-//Provides: jsoo_floor_log2
-var log2_ok = Math.log2 && Math.log2(1.1235582092889474e307) === 1020;
-function jsoo_floor_log2(x) {
-  if (log2_ok) return Math.floor(Math.log2(x));
-  var i = 0;
-  if (x === 0) return Number.NEGATIVE_INFINITY;
-  if (x >= 1) {
-    while (x >= 2) {
-      x /= 2;
-      i++;
-    }
-  } else {
-    while (x < 1) {
-      x *= 2;
-      i--;
-    }
-  }
-  return i;
-}
+//Provides: jsoo_dataview
+var jsoo_dataview = new DataView(new ArrayBuffer(8));
 
 //Provides: caml_int64_bits_of_float const
-//Requires: jsoo_floor_log2, caml_int64_create_lo_mi_hi
+//Requires: caml_int64_create_lo_mi_hi
+//Requires: jsoo_dataview
 function caml_int64_bits_of_float(x) {
-  if (!Number.isFinite(x)) {
-    if (Number.isNaN(x)) return caml_int64_create_lo_mi_hi(1, 0, 0x7ff0);
-    if (x > 0) return caml_int64_create_lo_mi_hi(0, 0, 0x7ff0);
-    else return caml_int64_create_lo_mi_hi(0, 0, 0xfff0);
-  }
-  var sign =
-    x === 0 && 1 / x === Number.NEGATIVE_INFINITY
-      ? 0x8000
-      : x >= 0
-        ? 0
-        : 0x8000;
-  if (sign) x = -x;
-  // Int64.bits_of_float 1.1235582092889474E+307 = 0x7fb0000000000000L
-  // using Math.LOG2E*Math.log(x) in place of Math.log2 result in precision lost
-  var exp = jsoo_floor_log2(x) + 1023;
-  if (exp <= 0) {
-    exp = 0;
-    x /= Math.pow(2, -1026);
-  } else {
-    x /= Math.pow(2, exp - 1027);
-    if (x < 16) {
-      x *= 2;
-      exp -= 1;
-    }
-    if (exp === 0) {
-      x /= 2;
-    }
-  }
-  var k = Math.pow(2, 24);
-  var r3 = x | 0;
-  x = (x - r3) * k;
-  var r2 = x | 0;
-  x = (x - r2) * k;
-  var r1 = x | 0;
-  r3 = (r3 & 0xf) | sign | (exp << 4);
+  jsoo_dataview.setFloat64(0, x, true);
+  var lo32 = jsoo_dataview.getUint32(0, true);
+  var hi32 = jsoo_dataview.getUint32(4, true);
+  var r1 = lo32 & 0xffffff;
+  var r2 = (lo32 >>> 24) | ((hi32 << 8) & 0xffffff);
+  var r3 = (hi32 >>> 16) & 0xffff;
   return caml_int64_create_lo_mi_hi(r1, r2, r3);
 }
 
 //Provides: caml_int32_bits_of_float const
-//Requires: jsoo_floor_log2
+//Requires: jsoo_dataview
 function caml_int32_bits_of_float(x) {
-  var float32a = new Float32Array(1);
-  float32a[0] = x;
-  var int32a = new Int32Array(float32a.buffer);
-  return int32a[0] | 0;
+  jsoo_dataview.setFloat32(0, x, true);
+  return jsoo_dataview.getUint32(0, true) | 0;
 }
 
 //FP literals can be written using the hexadecimal
@@ -150,24 +103,14 @@ function caml_hexstring_of_float(x, prec, style) {
 }
 
 //Provides: caml_int64_float_of_bits const
+//Requires: jsoo_dataview
 function caml_int64_float_of_bits(x) {
   var lo = x.lo;
   var mi = x.mi;
   var hi = x.hi;
-  var exp = (hi & 0x7fff) >> 4;
-  if (exp === 2047) {
-    if ((lo | mi | (hi & 0xf)) === 0)
-      return hi & 0x8000 ? Number.NEGATIVE_INFINITY : Number.POSITIVE_INFINITY;
-    else return Number.NaN;
-  }
-  var k = Math.pow(2, -24);
-  var res = (lo * k + mi) * k + (hi & 0xf);
-  if (exp > 0) {
-    res += 16;
-    res *= Math.pow(2, exp - 1027);
-  } else res *= Math.pow(2, -1026);
-  if (hi & 0x8000) res = -res;
-  return res;
+  jsoo_dataview.setUint32(0, lo | (mi << 24), true);
+  jsoo_dataview.setUint32(4, (mi >>> 8) | (hi << 16), true);
+  return jsoo_dataview.getFloat64(0, true);
 }
 
 //Provides: caml_nextafter_float const
@@ -192,11 +135,10 @@ function caml_trunc_float(x) {
 }
 
 //Provides: caml_int32_float_of_bits const
+//Requires: jsoo_dataview
 function caml_int32_float_of_bits(x) {
-  var int32a = new Int32Array(1);
-  int32a[0] = x;
-  var float32a = new Float32Array(int32a.buffer);
-  return float32a[0];
+  jsoo_dataview.setUint32(0, x, true);
+  return jsoo_dataview.getFloat32(0, true);
 }
 
 //Provides: caml_classify_float const
@@ -244,12 +186,11 @@ function caml_ldexp_float(x, exp) {
   return x;
 }
 //Provides: caml_frexp_float const
-//Requires: jsoo_floor_log2
 function caml_frexp_float(x) {
   if (x === 0 || !Number.isFinite(x)) return [0, x, 0];
   var neg = x < 0;
   if (neg) x = -x;
-  var exp = Math.max(-1023, jsoo_floor_log2(x) + 1);
+  var exp = Math.max(-1023, Math.floor(Math.log2(x)) + 1);
   x *= Math.pow(2, -exp);
   while (x < 0.5) {
     x *= 2;
@@ -482,7 +423,7 @@ function caml_fma_float(x, y, z) {
 }
 
 //Provides: caml_format_float const
-//Requires: caml_parse_format, caml_finish_formatting
+//Requires: caml_str_repeat, caml_parse_format, caml_finish_formatting
 function caml_format_float(fmt, x) {
   function toFixed(x, dp) {
     if (Math.abs(x) < 1.0) {
@@ -492,9 +433,9 @@ function caml_format_float(fmt, x) {
       if (e > 20) {
         e -= 20;
         x /= Math.pow(10, e);
-        x += new Array(e + 1).join("0");
+        x += caml_str_repeat(e, "0");
         if (dp > 0) {
-          x = x + "." + new Array(dp + 1).join("0");
+          x = x + "." + caml_str_repeat(dp, "0");
         }
         return x;
       } else return x.toFixed(dp);
diff --git a/runtime/js/mlBytes.js b/runtime/js/mlBytes.js
index 9e588d799d..fb9473db40 100644
--- a/runtime/js/mlBytes.js
+++ b/runtime/js/mlBytes.js
@@ -48,24 +48,7 @@
 
 //Provides: caml_str_repeat
 function caml_str_repeat(n, s) {
-  if (n === 0) return "";
-  if (s.repeat) {
-    return s.repeat(n);
-  } // ECMAscript 6 and Firefox 24+
-  var r = "",
-    l = 0;
-  for (;;) {
-    if (n & 1) r += s;
-    n >>= 1;
-    if (n === 0) return r;
-    s += s;
-    l++;
-    if (l === 9) {
-      s.slice(0, 1); // flatten the string
-      // then, the flattening of the whole string will be faster,
-      // as it will be composed of larger pieces
-    }
-  }
+  return s.repeat(n);
 }
 
 //Provides: caml_subarray_to_jsbytes