Merge pull request #77 from WebAssembly/nearest-fix

Avoid relying on correct rounding of mod_float.
WebAssembly · Sep 18, 2015 · accca7a · accca7a
2 parents 502fdf9 + be2d3a5
commit accca7a
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/ml-proto/src/given/float32.ml b/ml-proto/src/given/float32.ml
@@ -53,7 +53,8 @@ let nearest x =
   let d = Pervasives.floor xf in
   let um = abs_float (xf -. u) in
   let dm = abs_float (xf -. d) in
-  let u_or_d = um < dm || ((um = dm) && (mod_float u 2.0 = 0.0)) in
+  let u_or_d = um < dm ||
+               (um = dm && let h = u /. 2. in Pervasives.floor h = h) in
   let f = if u_or_d then u else d in
   bits_of_arith f
 

diff --git a/ml-proto/src/given/float64.ml b/ml-proto/src/given/float64.ml
@@ -53,7 +53,8 @@ let nearest x =
   let d = Pervasives.floor xf in
   let um = abs_float (xf -. u) in
   let dm = abs_float (xf -. d) in
-  let u_or_d = um < dm || ((um = dm) && (mod_float u 2.0 = 0.0)) in
+  let u_or_d = um < dm ||
+               (um = dm && let h = u /. 2. in Pervasives.floor h = h) in
   let f = if u_or_d then u else d in
   bits_of_arith f