[Buildroot] [PATCH v4 2/3] package/zstd: Change Build options

[Norbert Lange]

Disable the legacy format, these are just needed for
decompressing files created with pre-release version.

Use Buildroot's setting for optimization, zstd's build system
overrides CFLAGS, but MOREFLAGS can override again.
Quick tests show that using -O2 (like buildroot)
is actually a little faster than -O3 on x86_64 Atoms.

Signed-off-by: Norbert Lange <nolange79 at gmail.com>
---
v2->v3:
*   Remove ZSTD_OPTS_MOREFLAGS variable
---
 package/zstd/zstd.mk | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/package/zstd/zstd.mk b/package/zstd/zstd.mk
index 5674e85bfe..58b0d0099e 100644
--- a/package/zstd/zstd.mk
+++ b/package/zstd/zstd.mk
@@ -13,6 +13,7 @@ ZSTD_CPE_ID_VENDOR = facebook
 ZSTD_CPE_ID_PRODUCT = zstandard
 
 ZSTD_OPTS += PREFIX=/usr
+ZSTD_OPTS += ZSTD_LEGACY_SUPPORT=0
 
 ifeq ($(BR2_PACKAGE_ZLIB),y)
 ZSTD_DEPENDENCIES += zlib
@@ -35,6 +36,9 @@ else
 ZSTD_OPTS += HAVE_LZ4=0
 endif
 
+# zstd will append -O3 after $(CFLAGS), use MOREFLAGS to override again
+ZSTD_OPTS += MOREFLAGS="$(TARGET_OPTIMIZATION)"
+
 ZSTD_BUILD_PROG_TARGET = zstd-release
 
 ifeq ($(BR2_STATIC_LIBS)$(BR2_SHARED_STATIC_LIBS),y)
-- 
2.30.2