From 1f58f2047a00c51a6c3d33c2088851dbfde6964a Mon Sep 17 00:00:00 2001
From: xtqqczze <45661989+xtqqczze@users.noreply.github.com>
Date: Wed, 31 Dec 2025 20:43:22 +0000
Subject: [PATCH] uucore: switch to `u64::ilog2`

`u64::ilog2` has been available since Rust 1.67; MSRV is 1.85.

https://doc.rust-lang.org/std/primitive.u64.html#method.ilog2
---
 src/uucore/src/lib/features/parser/num_parser.rs | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/uucore/src/lib/features/parser/num_parser.rs b/src/uucore/src/lib/features/parser/num_parser.rs
index 178cd578fba..7d799b9881f 100644
--- a/src/uucore/src/lib/features/parser/num_parser.rs
+++ b/src/uucore/src/lib/features/parser/num_parser.rs
@@ -432,8 +432,7 @@ fn pow_with_context(bd: &BigDecimal, exp: i64, ctx: &Context) -> BigDecimal {
     // Count the number of multiplications we're going to perform, one per "1" binary digit
     // in exp, and the number of times we can divide exp by 2.
     let mut n = exp.unsigned_abs();
-    // Note: 63 - n.leading_zeros() == n.ilog2, but that's only available in recent Rust versions.
-    let muls = (n.count_ones() + (63 - n.leading_zeros()) - 1) as u64;
+    let muls = (n.count_ones() + n.ilog2() - 1) as u64;
     // Note: div_ceil would be nice to use here, but only available in recent Rust versions.
     // (see note above about minimum Rust version in use)
     let margin_extra = (muls + MUL_PER_MARGIN_EXTRA / 2) / MUL_PER_MARGIN_EXTRA;