WAT output: signed nan

Not very important since it is only used for debugging

Author: vouillon

compiler/lib-wasm/wat_output.ml

@@ -328,18 +328,22 @@ let float64 _ f =
   match classify_float f with
   | FP_normal | FP_subnormal | FP_zero -> Printf.sprintf "%h" f
   | FP_nan ->
+      let f = Int64.(bits_of_float f) in
       Printf.sprintf
-        "nan:0x%Lx"
-        Int64.(logand (bits_of_float f) (of_int ((1 lsl 52) - 1)))
+        "%snan:0x%Lx"
+        (if Int64.( >= ) f 0L then "" else "-")
+        Int64.(logand f (of_int ((1 lsl 52) - 1)))
   | FP_infinite -> if Float.(f > 0.) then "inf" else "-inf"
 
 let float32 _ f =
   match classify_float f with
   | FP_normal | FP_subnormal | FP_zero -> Printf.sprintf "%h" f
   | FP_nan ->
+      let f = Int32.(bits_of_float f) in
       Printf.sprintf
-        "nan:0x%lx"
-        Int32.(logand (bits_of_float f) (of_int ((1 lsl 23) - 1)))
+        "%snan:0x%lx"
+        (if Int32.( >= ) f 0l then "" else "-")
+        Int32.(logand f (of_int ((1 lsl 23) - 1)))
   | FP_infinite -> if Float.(f > 0.) then "inf" else "-inf"
 
 let expression_or_instructions ctx st in_function =