--- ghc-8.10.6.ebuild.orig	2022-02-17 23:29:38.998858167 -0500
+++ ghc-8.10.6.ebuild	2022-02-17 23:29:53.848348894 -0500
@@ -3,6 +3,8 @@
 
 EAPI=7
 
+inherit llvm
+
 # to make make a crosscompiler use crossdev and symlink ghc tree into
 # cross overlay. result would look like 'cross-sparc-unknown-linux-gnu/ghc'
 export CBUILD=${CBUILD:-${CHOST}}
@@ -86,8 +88,14 @@
 	elfutils? ( dev-libs/elfutils )
 	!ghcmakebinary? ( dev-libs/libffi:= )
 	numa? ( sys-process/numactl )
+	arm? (
+		<sys-devel/llvm-13:=
+		|| ( sys-devel/llvm:11 sys-devel/llvm:12 )
+	)
 "
 
+LLVM_MAX_SLOT=12
+
 # This set of dependencies is needed to run
 # prebuilt ghc. We specifically avoid ncurses
 # dependency with:
@@ -370,6 +378,8 @@
 pkg_setup() {
 	ghc-check-reqs check-reqs_pkg_setup
 
+	llvm_pkg_setup
+
 	# quiet portage about prebuilt binaries
 	use binary && QA_PREBUILT="*"
 
@@ -600,14 +610,15 @@
 			Windres=${CTARGET}-windres
 			DllWrap=${CTARGET}-dllwrap
 			# we set the linker explicitly below
-			--disable-ld-override
+#			--disable-ld-override
 		)
 		case ${CTARGET} in
 			arm*)
 				# ld.bfd-2.28 does not work for ghc. Force ld.gold
 				# instead. This should be removed once gentoo gets
 				# a fix for R_ARM_COPY bug: https://sourceware.org/PR16177
-				econf_args+=(LD=${CTARGET}-ld.gold)
+#				econf_args+=(LD=${CTARGET}-ld.gold)
+				econf_args+=("LLC=$(command -v llc)" OPT="$(command -v opt)")
 			;;
 			sparc*)
 				# ld.gold-2.28 does not work for ghc. Force ld.bfd