From 00de81166de77eb2939788a76a2ab7ffc9084216 Mon Sep 17 00:00:00 2001
From: Copilot <198982749+Copilot@users.noreply.github.com>
Date: Fri, 31 Jul 2026 19:33:49 -0700
Subject: [PATCH] Fix clang-tidy dead store warnings in util.cpp and
 model_based_opt.cpp (#10334)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Three `clang-analyzer-deadcode.DeadStores` warnings flagged by
clang-tidy: redundant bit-shifts in the log2 functions and an
unreachable assignment in `def::from_row()`.

## Changes

- **`src/util/util.cpp`** — `log2()` and `uint64_log2()`: Remove `v >>=
1` in the final `if (v & 0x2)` block. Only `r |= 1` matters; `v` is
never read after that point.

  ```cpp
  // Before
  if (v & 0x2) {
      v >>= 1;  // dead store
      r |=  1;
  }
  // After
  if (v & 0x2) {
      r |=  1;
  }
  ```

- **`src/math/simplex/model_based_opt.cpp`** — `def::from_row()`: Remove
`sign = true` assignment when `div < 0`. `sign` is only consumed earlier
in the function (`if (!sign)`) and is not read again after this point.

<!-- START COPILOT CODING AGENT SUFFIX -->

- Fixes #10333

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
---
 src/math/simplex/model_based_opt.cpp | 1 -
 src/util/util.cpp                    | 2 --
 2 files changed, 3 deletions(-)

diff --git a/src/math/simplex/model_based_opt.cpp b/src/math/simplex/model_based_opt.cpp
index ded6aa6450..d22d0fb8bd 100644
--- a/src/math/simplex/model_based_opt.cpp
+++ b/src/math/simplex/model_based_opt.cpp
@@ -73,7 +73,6 @@ namespace opt {
         }
 
         if (div < 0) {
-            sign = true;
             div.neg();
             lc.neg();
             coeff.neg();
diff --git a/src/util/util.cpp b/src/util/util.cpp
index b158cf9508..fbc13c6e0d 100644
--- a/src/util/util.cpp
+++ b/src/util/util.cpp
@@ -86,7 +86,6 @@ unsigned log2(unsigned v) {
         r |=  2;
     }
     if (v & 0x2) {
-        v >>= 1;
         r |=  1;
     }
     return r;
@@ -115,7 +114,6 @@ unsigned uint64_log2(uint64_t v) {
         r |=  2;
     }
     if (v & 0x2) {
-        v >>= 1;
         r |=  1;
     }
     return r;