Index: head/Makefile
===================================================================
--- head/Makefile
+++ head/Makefile
@@ -235,7 +235,7 @@
 _TARGET_ARCH=	${TARGET:S/pc98/i386/:S/arm64/aarch64/}
 .elif !defined(TARGET) && defined(TARGET_ARCH) && \
     ${TARGET_ARCH} != ${MACHINE_ARCH}
-_TARGET=		${TARGET_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb)?/arm/:C/aarch64/arm64/:C/powerpc64/powerpc/:C/riscv64/riscv/}
+_TARGET=		${TARGET_ARCH:${MACHINE_CPUARCH_SUB:ts:}}
 .endif
 .if defined(TARGET) && !defined(_TARGET)
 _TARGET=${TARGET}
Index: head/gnu/usr.bin/binutils/Makefile.inc0
===================================================================
--- head/gnu/usr.bin/binutils/Makefile.inc0
+++ head/gnu/usr.bin/binutils/Makefile.inc0
@@ -7,7 +7,7 @@
 VERSION=	"2.17.50 [FreeBSD] 2007-07-03"
 
 .if defined(TARGET_ARCH)
-TARGET_CPUARCH=${TARGET_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb)?/arm/:C/powerpc64/powerpc/}
+TARGET_CPUARCH=${TARGET_ARCH:${MACHINE_CPUARCH_SUB:ts:}}
 .else
 TARGET_CPUARCH=${MACHINE_CPUARCH}
 .endif
Index: head/gnu/usr.bin/cc/Makefile.tgt
===================================================================
--- head/gnu/usr.bin/cc/Makefile.tgt
+++ head/gnu/usr.bin/cc/Makefile.tgt
@@ -4,7 +4,7 @@
 # MACHINE_CPUARCH, but there's no easy way to export make functions...
 
 .if defined(TARGET_ARCH)
-TARGET_CPUARCH=${TARGET_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb)?/arm/:C/powerpc64/powerpc/}
+TARGET_CPUARCH=${TARGET_ARCH:${MACHINE_CPUARCH_SUB:ts:}}
 .else
 TARGET_CPUARCH=${MACHINE_CPUARCH}
 .endif
Index: head/gnu/usr.bin/gdb/Makefile.inc
===================================================================
--- head/gnu/usr.bin/gdb/Makefile.inc
+++ head/gnu/usr.bin/gdb/Makefile.inc
@@ -23,7 +23,7 @@
 # MACHINE_CPUARCH, but there's no easy way to export make functions...
 
 .if defined(TARGET_ARCH)
-TARGET_CPUARCH=${TARGET_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb)?/arm/:C/powerpc64/powerpc/}
+TARGET_CPUARCH=${TARGET_ARCH:${MACHINE_CPUARCH_SUB:ts:}}
 .else
 TARGET_CPUARCH=${MACHINE_CPUARCH}
 .endif
Index: head/gnu/usr.bin/gdb/libgdb/Makefile
===================================================================
--- head/gnu/usr.bin/gdb/libgdb/Makefile
+++ head/gnu/usr.bin/gdb/libgdb/Makefile
@@ -4,7 +4,7 @@
 # MACHINE_CPUARCH, but there's no easy way to export make functions...
 
 .if defined(TARGET_ARCH)
-TARGET_CPUARCH=${TARGET_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb)?/arm/:C/powerpc64/powerpc/}
+TARGET_CPUARCH=${TARGET_ARCH:${MACHINE_CPUARCH_SUB:ts:}}
 .else
 TARGET_CPUARCH=${MACHINE_CPUARCH}
 .endif
Index: head/share/mk/sys.mk
===================================================================
--- head/share/mk/sys.mk
+++ head/share/mk/sys.mk
@@ -13,7 +13,13 @@
 # and/or endian.  This is called MACHINE_CPU in NetBSD, but that's used
 # for something different in FreeBSD.
 #
-MACHINE_CPUARCH=${MACHINE_ARCH:C/mips(n32|64)?(el)?/mips/:C/arm(v6)?(eb|hf)?/arm/:C/powerpc64/powerpc/:C/riscv64/riscv/}
+MACHINE_CPUARCH_SUB= \
+		C/mips(n32|64)?(el)?/mips/ \
+		C/arm(v6)?(eb|hf)?/arm/ \
+		C/aarch64/arm64/ \
+		C/powerpc64/powerpc/ \
+		C/riscv64/riscv/
+MACHINE_CPUARCH=${MACHINE_ARCH:${MACHINE_CPUARCH_SUB:ts:}}
 .endif