zig

commit 82f35c51866826fb71eb6f27d9210bb738d602e9 (tree)
parent a68119f8f1d54b70e713e1e8ce07491ddba0f093
Author: David Rubin <daviru007@icloud.com>
Date:   Thu, 12 Dec 2024 18:23:48 -0800

add branchHint to `std.Random.float`

Diffstat:
M
lib/std/Random.zig
 | 
6
+++---

1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/lib/std/Random.zig b/lib/std/Random.zig
@@ -271,11 +271,10 @@ pub fn float(r: Random, comptime T: type) T {
             const rand = r.int(u64);
             var rand_lz = @clz(rand);
             if (rand_lz >= 41) {
-                // TODO: when #5177 or #489 is implemented,
-                // tell the compiler it is unlikely (1/2^41) to reach this point.
-                // (Same for the if branch and the f64 calculations below.)
+                @branchHint(.unlikely);
                 rand_lz = 41 + @clz(r.int(u64));
                 if (rand_lz == 41 + 64) {
+                    @branchHint(.unlikely);
                     // It is astronomically unlikely to reach this point.
                     rand_lz += @clz(r.int(u32) | 0x7FF);
                 }
@@ -297,6 +296,7 @@ pub fn float(r: Random, comptime T: type) T {
                     const addl_rand_lz = @clz(r.int(u64));
                     rand_lz += addl_rand_lz;
                     if (addl_rand_lz != 64) {
+                        @branchHint(.likely);
                         break;
                     }
                     if (rand_lz >= 1022) {