From 2f74e7a78486ea6c977b3d09527a2bb2f12d44c9 Mon Sep 17 00:00:00 2001
From: yuanhecai <yuanhecai@loongson.cn>
Date: Wed, 26 Aug 2026 16:12:59 +0800
Subject: [PATCH] loongarch: Fix per-ISA build flags

Compile LSX and LASX sources separately (-mlsx vs -mlasx)
to avoid emitting LASX instructions in LSX kernels, which
crashed on LSX-only CPUs.

Change-Id: I56003cee9bb750cdac8fa19a5c95efb8889ba9e0
Reviewed-on: https://chromium-review.googlesource.com/c/libyuv/libyuv/+/8294723
Reviewed-by: Wan-Teh Chang <wtc@google.com>
Commit-Queue: Wan-Teh Chang <wtc@google.com>
Reviewed-by: Frank Barchard <fbarchard@google.com>
---
 CMakeLists.txt | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 77e0527fc..4006a59d3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -40,13 +40,10 @@ set ( ly_common_source_files
   ${ly_src_dir}/rotate.cc
   ${ly_src_dir}/rotate_common.cc
   ${ly_src_dir}/rotate_gcc.cc
-  ${ly_src_dir}/rotate_lsx.cc
   ${ly_src_dir}/rotate_win.cc
   ${ly_src_dir}/row_any.cc
   ${ly_src_dir}/row_common.cc
   ${ly_src_dir}/row_gcc.cc
-  ${ly_src_dir}/row_lasx.cc
-  ${ly_src_dir}/row_lsx.cc
   ${ly_src_dir}/row_rvv.cc
   ${ly_src_dir}/row_win.cc
   ${ly_src_dir}/scale_any.cc
@@ -54,7 +51,6 @@ set ( ly_common_source_files
   ${ly_src_dir}/scale.cc
   ${ly_src_dir}/scale_common.cc
   ${ly_src_dir}/scale_gcc.cc
-  ${ly_src_dir}/scale_lsx.cc
   ${ly_src_dir}/scale_rgb.cc
   ${ly_src_dir}/scale_rvv.cc
   ${ly_src_dir}/scale_uv.cc
@@ -162,10 +158,21 @@ if(LOONGARCH64)
     return 0; }" SUPPORTS_LASX)
 
   if(SUPPORTS_LSX)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mlsx")
+    # These kernels use only LSX (128-bit) instructions and must not be
+    # compiled with -mlasx, which would let the compiler emit 256-bit LASX
+    # code (e.g. for stack-array copies) and crash on LSX-only CPUs.
+    add_library(${ly_lib_name}_lsx OBJECT
+      ${ly_src_dir}/rotate_lsx.cc
+      ${ly_src_dir}/row_lsx.cc
+      ${ly_src_dir}/scale_lsx.cc)
+    target_compile_options(${ly_lib_name}_lsx PRIVATE -mlsx)
+    list(APPEND ly_lib_parts $<TARGET_OBJECTS:${ly_lib_name}_lsx>)
   endif()
   if(SUPPORTS_LASX)
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -mlasx")
+    add_library(${ly_lib_name}_lasx OBJECT
+      ${ly_src_dir}/row_lasx.cc)
+    target_compile_options(${ly_lib_name}_lasx PRIVATE -mlasx)
+    list(APPEND ly_lib_parts $<TARGET_OBJECTS:${ly_lib_name}_lasx>)
   endif()
 endif()