gentoo-overlay/games-engines/odamex/files/odamex-10.4.0-backport-pr928.patch

https://bugs.gentoo.org/849866
https://github.com/odamex/odamex/pull/928

From b952137ac487a6558e1796c86d8fd55b8b3c9025 Mon Sep 17 00:00:00 2001
From: matoro <matoro@users.noreply.github.com>
Date: Wed, 6 Dec 2023 01:01:29 -0500
Subject: [PATCH] Fix auto-SIMD for i386+sse2, ppc+altivec

Only Darwin ever used -faltivec, gcc uses -maltivec since at least 2007:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=30254#c1

Similarly, recent versions of gcc define __APPLE_ALTIVEC__ for
compatibility, so just unconditionally include altivec.h.

Canonical way to enable specific extensions is e.g. -msse2, use that
instead of optimizing for a specific CPU.

Finally, cmake uses target_compile_options to add arbitrary flags.
target_compile_definitions assumes you want a preprocessor definition,
which was adding "-D-faltivec" to the command line which gcc doesn't
like; this is what originally prompted this change.
---
 client/CMakeLists.txt          | 11 +++++++----
 client/src/r_drawt_altivec.cpp |  2 --
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/client/CMakeLists.txt b/client/CMakeLists.txt
index 646164916..56caf04f8 100644
--- a/client/CMakeLists.txt
+++ b/client/CMakeLists.txt
@@ -169,14 +169,17 @@ if(TARGET SDL2::SDL2 OR TARGET SDL::SDL)
       message(STATUS "Default SIMD flags not touched for AMD64")
     elseif(ODAMEX_TARGET_ARCH STREQUAL "i386")
       if(NOT MSVC)
-        # Pentium M has SSE2.
-        target_compile_definitions(odamex PRIVATE -march=pentium-m)
+        target_compile_options(odamex PRIVATE -msse2)
       else()
-        target_compile_definitions(odamex PRIVATE /arch:SSE2)
+        target_compile_options(odamex PRIVATE /arch:SSE2)
       endif()
       message(STATUS "Default SIMD flags set to SSE2")
     elseif(ODAMEX_TARGET_ARCH MATCHES "ppc")
-      target_compile_definitions(odamex PRIVATE -faltivec)
+      if(APPLE)
+        target_compile_options(odamex PRIVATE -faltivec)
+      else()
+        target_compile_options(odamex PRIVATE -maltivec)
+      endif()
       message(STATUS "Default SIMD flags set to AltiVec")
     endif()
   else()
diff --git a/client/src/r_drawt_altivec.cpp b/client/src/r_drawt_altivec.cpp
index eea758733..5a0cdf95e 100644
--- a/client/src/r_drawt_altivec.cpp
+++ b/client/src/r_drawt_altivec.cpp
@@ -36,9 +36,7 @@
 #include "r_main.h"
 #include "i_video.h"
 
-#if !defined(__APPLE_ALTIVEC__)
 #include <altivec.h>
-#endif
 
 #define ALTIVEC_ALIGNED(x) x __attribute__((aligned(16)))