--- a/gcc.SlackBuild	2022-05-06 18:12:35.665696515 +0000
+++ b/gcc.SlackBuild	2022-05-08 13:55:05.363287028 +0000
@@ -115,6 +115,14 @@
   SLKCFLAGS="-O3 -march=armv7-a -mfpu=vfpv3-d16"
   LIBDIRSUFFIX=""
   LIB_ARCH=armv7hl
+elif [ "$ARCH" = "aarch64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
+  LIB_ARCH=$ARCH
+elif [ "$ARCH" = "riscv64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
+  LIB_ARCH=$ARCH
 else
   SLKCFLAGS="-O2"
   LIBDIRSUFFIX=""
@@ -163,6 +171,12 @@
 # Smite the fixincludes:
 zcat $CWD/patches/gcc-no_fixincludes.diff.gz | patch -p1 --verbose --backup --suffix=.orig || exit 1
 
+# Redefine dynamic linker for aarch64 from /lib to /lib64:
+xzcat $CWD/redefine-dynamic-linker-for-aarch64.patch.xz | patch -p1 --verbose || exit 1
+
+# Redefine dynamic linker for riscv64 from /lib to /lib64:
+xzcat $CWD/redefine-dynamic-linker-for-riscv64.patch.xz | patch -p1 --verbose || exit 1
+
 # Fix perms/owners:
 chown -R root:root .
 find . \
@@ -322,6 +336,9 @@
   else
     GCC_ARCHOPTS="--disable-multilib"
   fi
+
+  [[ "$ARCH" == "aarch64" ]] && GCC_ARCHOPTS="--enable-multilib"
+  [[ "$ARCH" == "riscv64" ]] && GCC_ARCHOPTS="--disable-multilib --with-slibdir=/lib$LIBDIRSUFFIX"
  
   CFLAGS="$SLKCFLAGS" \
   CXXFLAGS="$SLKCFLAGS" \
@@ -392,7 +409,7 @@
   fi
 
   # Make our 64bit gcc look for 32bit gcc binaries in ./32 subdirectory:
-  if [ "$ARCH" = "x86_64" ]; then
+  if [ "${LIBDIRSUFFIX}" = "64" ]; then
     sed -i 's#;.\(:../lib !m64 m32;\)$#;32\1#' \
       $PKG1/usr/lib${LIBDIRSUFFIX}/gcc/${TARGET}/${VERSION}/specs
   fi