From 35d4939701da2bd16becfb845842e04ba254ce5e Mon Sep 17 00:00:00 2001
From: SupervisedThinking <supervisedthinking@gmail.com>
Date: Fri, 17 Jun 2022 20:09:44 +0200
Subject: [PATCH] config/arch.x86_64: updated TARGET_CPU & TARGET_FEATURES

---
 config/arch.x86_64       | 36 +++++++++++++++++++++---------------
 projects/Generic/options | 11 ++++++++---
 2 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/config/arch.x86_64 b/config/arch.x86_64
index d4e246cead..531c4c25a0 100644
--- a/config/arch.x86_64
+++ b/config/arch.x86_64
@@ -1,24 +1,30 @@
 # determines TARGET_CPU, if not forced by user
-  if [ -z "$TARGET_CPU" ]; then
-    TARGET_CPU=core2
-  fi
-
-  # 64bit userland
-  if [ -z "${TARGET_FEATURES}" ]; then
-    TARGET_FEATURES="64bit"
-  else
-    TARGET_FEATURES+=" 64bit"
+  if [ -z "${TARGET_CPU}" ]; then
+    TARGET_CPU="x86-64"
   fi
 
 # determine architecture's family
-  TARGET_SUBARCH=x86_64
+  TARGET_SUBARCH="x86_64"
 
   TARGET_GCC_ARCH="${TARGET_SUBARCH/-/}"
-  TARGET_KERNEL_ARCH=x86
+  TARGET_KERNEL_ARCH="x86"
 
 # setup ARCH specific *FLAGS
-  TARGET_CFLAGS="-march=$TARGET_CPU"
-  TARGET_LDFLAGS="-march=$TARGET_CPU"
+  TARGET_CFLAGS="-march=${TARGET_CPU}"
+  TARGET_LDFLAGS="-march=${TARGET_CPU}"
 
-# build with SIMD support ( yes / no )
-  TARGET_FEATURES+=" mmx sse sse2"
+# build with microarchitecture feature support defined by the TARGET_CPU value
+# see https://gitlab.com/x86-psABIs/x86-64-ABI/-/wikis/home for further details
+  TARGET_FEATURES="64bit cmov cx8 fpu fxsr mmx osfxsr sce sse sse2"
+  TARGET_FEATURES_X86_64_V2="cmpxchg16b lahf-sahf popcnt sse3 sse4_1 sse4_2 ssse3"
+  TARGET_FEATURES_X86_64_V3="avx avx2 bmi1 bmi2 f16c fma lzcnt movbe osxsave"
+  if [ "${TARGET_CPU}" = "x86-64" ]; then
+    TARGET_FEATURES+=" no_sahf"
+  elif [ "${TARGET_CPU}" = "x86-64-v2" ]; then
+    TARGET_FEATURES+=" ${TARGET_FEATURES_X86_64_V2}"
+  elif [ "${TARGET_CPU}" = "x86-64-v3" ]; then
+    TARGET_FEATURES+=" ${TARGET_FEATURES_X86_64_V2} ${TARGET_FEATURES_X86_64_V3}"
+  else
+    TARGET_FEATURES+=" UNKNOWN_ADDITIONAL_CPU_SPECIFIC_FEATURES"
+  fi
+  TARGET_FEATURES="$(echo ${TARGET_FEATURES} | xargs -n1 | sort -u | xargs)"
diff --git a/projects/Generic/options b/projects/Generic/options
index 80b0cb29ef..841334559b 100644
--- a/projects/Generic/options
+++ b/projects/Generic/options
@@ -6,10 +6,15 @@
   # generated code.
     case $TARGET_ARCH in
       x86_64)
-        # (AMD CPUs)    k8 k8-sse3 opteron opteron-sse3 athlon64 athlon64-sse3
-        #               athlon-fx amdfam10 barcelona
-        # (Intel CPUs)  atom core2 nocona
+        # Valid TARGET_CPU values as defined at:
+        # https://gcc.gnu.org/onlinedocs/gcc/x86-Options.html
+        # x86-64       A generic CPU with 64-bit extensions.
         #
+        # x86-64-v2    e.g. AMD CPU - Bulldozer - (bdver1)
+        #                   Intel CPU - Nehalem - (nehalem)
+        #
+        # x86-64-v3    e.g. AMD CPU - Bulldozer GEN4 - (bdver4)
+        #                   Intel CPU - Haswell - (haswell)
         TARGET_CPU="x86-64"
         ;;
     esac