[OE-core] [PATCH v2] tune-i686: Add new tune for better support of 686-class CPUs.

[Carlos Alberto Lopez Perez]

There isn't currently any tune available for i686 x86 optimizations.
The tune for i586 doesn't enable i686 specific optimizations, and the
one for core2 enables things that won't work on a i686 CPU (like SSE3).

Make the tune for core2 inherits from this one and move there the
setting of X86ARCH32.

Signed-off-by: Carlos Alberto Lopez Perez <clopez at igalia.com>
---
 meta/conf/machine/include/tune-core2.inc |  7 ++-----
 meta/conf/machine/include/tune-i686.inc  | 27 +++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 5 deletions(-)
 create mode 100644 meta/conf/machine/include/tune-i686.inc

diff --git a/meta/conf/machine/include/tune-core2.inc b/meta/conf/machine/include/tune-core2.inc
index f4ba43fbfd..6a03466650 100644
--- a/meta/conf/machine/include/tune-core2.inc
+++ b/meta/conf/machine/include/tune-core2.inc
@@ -8,11 +8,8 @@
 #
 DEFAULTTUNE ?= "core2-32"
 
-# Set x86 target arch to i686, so that glibc enables SSE optimised memcpy, etc.
-X86ARCH32 ?= "i686"
-
 # Include the previous tune to pull in PACKAGE_EXTRA_ARCHS
-require conf/machine/include/tune-i586.inc
+require conf/machine/include/tune-i686.inc
 
 # Extra tune features
 TUNEVALID[core2] = "Enable core2 specific processor optimizations"
@@ -23,7 +20,7 @@ AVAILTUNES += "core2-32"
 TUNE_FEATURES_tune-core2-32 = "${TUNE_FEATURES_tune-x86} core2"
 BASE_LIB_tune-core2-32 = "lib"
 TUNE_PKGARCH_tune-core2-32 = "core2-32"
-PACKAGE_EXTRA_ARCHS_tune-core2-32 = "${PACKAGE_EXTRA_ARCHS_tune-i586} core2-32"
+PACKAGE_EXTRA_ARCHS_tune-core2-32 = "${PACKAGE_EXTRA_ARCHS_tune-i686} core2-32"
 
 AVAILTUNES += "core2-64"
 TUNE_FEATURES_tune-core2-64 = "${TUNE_FEATURES_tune-x86-64} core2"
diff --git a/meta/conf/machine/include/tune-i686.inc b/meta/conf/machine/include/tune-i686.inc
new file mode 100644
index 0000000000..bdb4799209
--- /dev/null
+++ b/meta/conf/machine/include/tune-i686.inc
@@ -0,0 +1,27 @@
+#
+# The i686 CPU family was introduced with the Intel Pentium Pro in 1995.
+# It has as required feature flags: fpu tsc cx8 cmov.
+#
+# It is the minimum CPU required by the Debian i386 port.
+# https://lists.debian.org/debian-devel-announce/2016/05/msg00001.html
+#
+#
+
+DEFAULTTUNE ?= "i686"
+
+# Set x86 target arch to i686, so that glibc enables SSE optimised memcpy, etc.
+X86ARCH32 ?= "i686"
+
+# Include the previous tune to pull in PACKAGE_EXTRA_ARCHS
+require conf/machine/include/tune-i586.inc
+
+# Extra tune features
+TUNEVALID[i686] = "Enable i686 specific processor optimizations"
+TUNE_CCARGS .= "${@bb.utils.contains('TUNE_FEATURES', 'i686', ' -march=i686', '', d)}"
+
+# Extra tune selections
+AVAILTUNES += "i686"
+TUNE_FEATURES_tune-i686 = "${TUNE_FEATURES_tune-x86} i686"
+BASE_LIB_tune-i686 = "lib"
+TUNE_PKGARCH_tune-i686 = "i686"
+PACKAGE_EXTRA_ARCHS_tune-i686 = "${PACKAGE_EXTRA_ARCHS_tune-i586} i686"
-- 
2.11.0