zig

commit f50c0c664f3bd7a56c0274ffecae28e2b41c8d20 (tree)
parent eb6a8e6a3bba061c4a7fb18f53976e1fb683c3d4
Author: Marc Tiehuis <marctiehuis@gmail.com>
Date:   Thu, 21 Jun 2018 17:13:53 +1200

Add float repr bit extraction functions

Diffstat:
M
std/math/index.zig
 | 
27
++++++++++++++++++++++++++-

1 file changed, 26 insertions(+), 1 deletion(-)
diff --git a/std/math/index.zig b/std/math/index.zig
@@ -183,6 +183,32 @@ test "math" {
     _ = @import("big/index.zig");
 }
 
+pub fn floatMantissaBits(comptime T: type) comptime_int {
+    assert(@typeId(T) == builtin.TypeId.Float);
+
+    return switch (T.bit_count) {
+        16 => 10,
+        32 => 23,
+        64 => 52,
+        80 => 64,
+        128 => 112,
+        else => @compileError("unknown floating point type " ++ @typeName(T)),
+    };
+}
+
+pub fn floatExponentBits(comptime T: type) comptime_int {
+    assert(@typeId(T) == builtin.TypeId.Float);
+
+    return switch (T.bit_count) {
+        16 => 5,
+        32 => 8,
+        64 => 11,
+        80 => 15,
+        128 => 15,
+        else => @compileError("unknown floating point type " ++ @typeName(T)),
+    };
+}
+
 pub fn min(x: var, y: var) @typeOf(x + y) {
     return if (x < y) x else y;
 }
@@ -607,4 +633,3 @@ pub fn lossyCast(comptime T: type, value: var) T {
         else => @compileError("bad type"),
     }
 }
-