From 72f2b8a034235ff0942fcca8646ad2bb66c8b454 Mon Sep 17 00:00:00 2001
From: Rhys Perry <pendingchaos02@gmail.com>
Date: Tue, 7 Apr 2026 09:46:27 +0100
Subject: [PATCH] util: fix UBSan error with _mesa_bfloat16_bits_to_float

runtime error: left shift of 65535 by 16 places cannot be represented in type 'int'

This fixes nir_opt_algebraic_pattern_test.bf2f.

Signed-off-by: Rhys Perry <pendingchaos02@gmail.com>
Fixes: ecd2d2cf46df ("util: Add functions to convert float to/from bfloat16")
Reviewed-by: Georg Lehmann <dadschoorse@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/40740>
---
 src/util/bfloat.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/util/bfloat.h b/src/util/bfloat.h
index 886d55fb8ba..013c38e7e24 100644
--- a/src/util/bfloat.h
+++ b/src/util/bfloat.h
@@ -63,7 +63,7 @@ static inline float
 _mesa_bfloat16_bits_to_float(uint16_t bf)
 {
    union fi x;
-   x.ui = bf << 16;
+   x.ui = (uint32_t)bf << 16;
 
    return x.f;
 }