From c5e535505c984d11640114c8a558bdc5ab8e23c2 Mon Sep 17 00:00:00 2001
From: Ian Leonard <antonlacon@gmail.com>
Date: Sat, 18 May 2019 03:16:40 +0000
Subject: [PATCH] buildsystem: add package flags to set compiler optimization

speed: use O3
size: use Os
default: use O2

The priority order is to use speed if set, then size, and fallback
to default when neither are set.

Signed-off-by: Ian Leonard <antonlacon@gmail.com>
---
 config/functions | 12 ++++++++++++
 config/optimize  | 13 +++++++++++--
 2 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/config/functions b/config/functions
index 793ba089ca..d7f85ffe88 100644
--- a/config/functions
+++ b/config/functions
@@ -221,6 +221,18 @@ setup_toolchain() {
     TARGET_LDFLAGS+=" $LDFLAGS_OPTIM_GOLD"
   fi
 
+  # compiler optimization, descending priority: speed, size, default
+  if flag_enabled "speed" "no"; then
+    TARGET_CFLAGS+=" $CFLAGS_OPTIM_SPEED"
+    TARGET_CXXFLAGS+=" $CXXFLAGS_OPTIM_SPEED"
+  elif flag_enabled "size" "no"; then
+    TARGET_CFLAGS+=" $CFLAGS_OPTIM_SIZE"
+    TARGET_CXXFLAGS+=" $CXXFLAGS_OPTIM_SIZE"
+  else
+    TARGET_CFLAGS+=" $CXXFLAGS_OPTIM_DEFAULT"
+    TARGET_CXXFLAGS+=" $CXXFLAGS_OPTIM_DEFAULT"
+  fi
+
   # position-independent code
   if flag_enabled "pic" "no"; then
     TARGET_CFLAGS+=" $CFLAGS_OPTIM_PIC"
diff --git a/config/optimize b/config/optimize
index 08d38b3b97..9c57fcaa92 100644
--- a/config/optimize
+++ b/config/optimize
@@ -1,4 +1,3 @@
-GCC_OPTIM="-Os"
 # Linker hash-style is set to gnu via gcc default
 LD_OPTIM="-Wl,--as-needed"
 
@@ -15,7 +14,7 @@ fi
 NINJA_OPTS=""
 
 TARGET_CPPFLAGS=""
-TARGET_CFLAGS="$TARGET_CFLAGS -Wall -pipe $GCC_OPTIM $PROJECT_CFLAGS"
+TARGET_CFLAGS="$TARGET_CFLAGS -Wall -pipe $PROJECT_CFLAGS"
 TARGET_CXXFLAGS="$TARGET_CFLAGS"
 TARGET_LDFLAGS="$TARGET_LDFLAGS $LD_OPTIM"
 TARGET_LIBDIR="$SYSROOT_PREFIX/lib $SYSROOT_PREFIX/usr/lib"
@@ -43,6 +42,16 @@ LDFLAGS_OPTIM_LTO_COMMON="-fuse-linker-plugin"
 # gold flags
 LDFLAGS_OPTIM_GOLD="-fuse-ld=gold"
 
+# default compiler optimization
+CFLAGS_OPTIM_DEFAULT="-O2"
+CXXFLAGS_OPTIM_DEFAULT="$CFLAGS_OPTIM_DEFAULT"
+# speed flag
+CFLAGS_OPTIM_SPEED="-O3"
+CXXFLAGS_OPTIM_SPEED="$CFLAGS_OPTIM_SPEED"
+# size flag
+CFLAGS_OPTIM_SIZE="-Os"
+CXXFLAGS_OPTIM_SIZE="$CFLAGS_OPTIM_SIZE"
+
 # position-independent code
 CFLAGS_OPTIM_PIC="-fPIC -DPIC"
 CXXFLAGS_OPTIM_PIC="-fPIC -DPIC"