From ba5e097fa6cd6fe89c238084cdff59a11131c6d2 Mon Sep 17 00:00:00 2001
From: Andrew Eiche <1386498+buddingmonkey@users.noreply.github.com>
Date: Thu, 6 Aug 2026 08:51:58 -0500
Subject: [PATCH 1/2] Build libultraship into the binary directory and the host
 asset packer optimised

Two independent build fixes to the top-level CMakeLists.txt.

The second argument to add_subdirectory() is the *binary* directory, but it
was pointed at the source directory. That made libultraship write its entire
build output -- CMakeScripts, cmake_install.cmake, generated headers and every
target's .a -- into the submodule's source tree, so every build directory
shared one output location. Two builds running at once would overwrite each
other's artifacts, and `git status` inside the submodule was permanently
dirty. Dropping the argument lets CMake place the output under the binary
directory as usual. Note that this relocates libultraship's build output:
anyone with scripts or tooling that reference build artefacts inside the
libultraship/ source tree will need to update those paths.

Separately, TorchExternal was being built without optimisation.
ExternalProject does not inherit CMAKE_BUILD_TYPE, and an empty build type on
a single-config generator -- Ninja or Makefiles, which is the normal Linux and
macOS command-line path -- means no optimisation flags at all, so the packer
was compiled -O0 even from a Release tree. Torch is a build-time asset packer,
so it is now configured Release explicitly regardless of the host project's
configuration. Multi-config generators such as Visual Studio and Xcode ignore
CMAKE_BUILD_TYPE at configure time and are unaffected either way.

The cost was not subtle. Extracting bk.o2r from a 16 MB ROM on the same
machine took 2312.96 s (38.5 minutes) unoptimised versus 38.28 s at -O3,
roughly 60x, for byte-identical 24 MB output. The work is single-threaded and
99.8% user CPU, so this was never I/O or memory bound.
---
 CMakeLists.txt | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index b4e2ec1ad..ba5c47895 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -370,7 +370,7 @@ if (CMAKE_GENERATOR MATCHES "Visual Studio")
     )
 endif()
 
-add_subdirectory(libultraship ${CMAKE_CURRENT_SOURCE_DIR}/libultraship)
+add_subdirectory(libultraship)
 add_dependencies(${PROJECT_NAME} libultraship)
 target_link_libraries(${PROJECT_NAME} PRIVATE libultraship)
 
@@ -743,7 +743,7 @@ include(ExternalProject)
 ExternalProject_Add(TorchExternal
 	PREFIX TorchExternal
     SOURCE_DIR ${CMAKE_SOURCE_DIR}/Torch
-    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/Torch -DENABLE_ASAN=${ENABLE_ASAN}
+    CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_BINARY_DIR}/Torch -DENABLE_ASAN=${ENABLE_ASAN} -DCMAKE_BUILD_TYPE=Release
 )
 #set_target_properties(TorchExternal PROPERTIES EXCLUDE_FROM_DEFAULT_BUILD TRUE)
 ExternalProject_Get_Property(TorchExternal install_dir)

From dc9642dae2f7643157bc5b37786bc7954ef1680b Mon Sep 17 00:00:00 2001
From: Andrew Eiche <1386498+buddingmonkey@users.noreply.github.com>
Date: Fri, 7 Aug 2026 14:07:57 -0500
Subject: [PATCH 2/2] Name libultraship's binary directory explicitly

Omitting the second argument to add_subdirectory() already resolves to
${CMAKE_CURRENT_BINARY_DIR}/libultraship, so this is not a behavior change --
it just states the destination rather than relying on the default.
---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ba5c47895..c6316c1b8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -370,7 +370,7 @@ if (CMAKE_GENERATOR MATCHES "Visual Studio")
     )
 endif()
 
-add_subdirectory(libultraship)
+add_subdirectory(libultraship ${CMAKE_CURRENT_BINARY_DIR}/libultraship)
 add_dependencies(${PROJECT_NAME} libultraship)
 target_link_libraries(${PROJECT_NAME} PRIVATE libultraship)