diff --git a/ChangeLog b/ChangeLog
index ac6799c..f40c754 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2010-03-23  Joseph Myers  <joseph@codesourcery.com>
+
+	* config.sub: Always map c54x-*, c55x-* and c6x-* to corresponding
+	tic54x, tic55x and tic6x names.  Only use -coff as a default OS if
+	no OS specified.
+	* testsuite/config-sub.data: Add test cases.
+
 2010-01-22  Chris Metcalf  <cmetcalf@tilera.com>
 	    Ben Elliston  <bje@gnu.org>
 
diff --git a/config.sub b/config.sub
index c2d1257..ae35431 100755
--- a/config.sub
+++ b/config.sub
@@ -4,7 +4,7 @@
 #   2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
 #   Free Software Foundation, Inc.
 
-timestamp='2010-01-22'
+timestamp='2010-03-22'
 
 # This file is (in principle) common to ALL GNU software.
 # The presence of a machine in this file suggests that SOME GNU software
@@ -295,7 +295,7 @@ case $basic_machine in
 	| sparc | sparc64 | sparc64b | sparc64v | sparc86x | sparclet | sparclite \
 	| sparcv8 | sparcv9 | sparcv9b | sparcv9v \
 	| spu | strongarm \
-	| tahoe | thumb | tic4x | tic80 | tron \
+	| tahoe | thumb | tic4x | tic54x | tic55x | tic6x | tic80 | tron \
 	| ubicom32 \
 	| v850 | v850e \
 	| we32k \
@@ -303,6 +303,15 @@ case $basic_machine in
 	| z8k | z80)
 		basic_machine=$basic_machine-unknown
 		;;
+	c54x)
+		basic_machine=tic54x-unknown
+		;;
+	c55x)
+		basic_machine=tic55x-unknown
+		;;
+	c6x)
+		basic_machine=tic6x-unknown
+		;;
 	m6811 | m68hc11 | m6812 | m68hc12 | picochip)
 		# Motorola 68HC11/12.
 		basic_machine=$basic_machine-unknown
@@ -334,7 +343,7 @@ case $basic_machine in
 	| arm-*  | armbe-* | armle-* | armeb-* | armv*-* \
 	| avr-* | avr32-* \
 	| bfin-* | bs2000-* \
-	| c[123]* | c30-* | [cjt]90-* | c4x-* | c54x-* | c55x-* | c6x-* \
+	| c[123]* | c30-* | [cjt]90-* | c4x-* \
 	| clipper-* | craynv-* | cydra-* \
 	| d10v-* | d30v-* | dlx-* \
 	| elxsi-* \
@@ -482,6 +491,15 @@ case $basic_machine in
 		basic_machine=powerpc-ibm
 		os=-cnk
 		;;
+	c54x-*)
+		basic_machine=tic54x-`echo $basic_machine | sed 's/^[^-]*-//'`
+		;;
+	c55x-*)
+		basic_machine=tic55x-`echo $basic_machine | sed 's/^[^-]*-//'`
+		;;
+	c6x-*)
+		basic_machine=tic6x-`echo $basic_machine | sed 's/^[^-]*-//'`
+		;;
 	c90)
 		basic_machine=c90-cray
 		os=-unicos
@@ -1075,18 +1093,6 @@ case $basic_machine in
 		basic_machine=t90-cray
 		os=-unicos
 		;;
-	tic54x | c54x*)
-		basic_machine=tic54x-unknown
-		os=-coff
-		;;
-	tic55x | c55x*)
-		basic_machine=tic55x-unknown
-		os=-coff
-		;;
-	tic6x | c6x*)
-		basic_machine=tic6x-unknown
-		os=-coff
-		;;
         # This must be matched before tile*.
         tilegx*)
 		basic_machine=tilegx-unknown
@@ -1484,6 +1490,15 @@ case $basic_machine in
         c4x-* | tic4x-*)
         	os=-coff
 		;;
+	tic54x-*)
+		os=-coff
+		;;
+	tic55x-*)
+		os=-coff
+		;;
+	tic6x-*)
+		os=-coff
+		;;
 	# This must come before the *-dec entry.
 	pdp10-*)
 		os=-tops20
diff --git a/testsuite/config-sub.data b/testsuite/config-sub.data
index a579755..80c5fc6 100644
--- a/testsuite/config-sub.data
+++ b/testsuite/config-sub.data
@@ -166,3 +166,35 @@ ubicom32-elf			ubicom32-unknown-elf
 i586-auroraux			i586-pc-auroraux
 i586-auroraux5.0		i586-pc-auroraux5.0
 i386-pc-nacl			i386-pc-nacl
+c54x				tic54x-unknown-coff
+c54x-coff			tic54x-unknown-coff
+c54x-none-coff			tic54x-none-coff
+c54x-unknown-coff		tic54x-unknown-coff
+tic54x				tic54x-unknown-coff
+tic54x-coff			tic54x-unknown-coff
+tic54x-none-coff		tic54x-none-coff
+tic54x-unknown-coff		tic54x-unknown-coff
+c55x				tic55x-unknown-coff
+c55x-coff			tic55x-unknown-coff
+c55x-none-coff			tic55x-none-coff
+c55x-unknown-coff		tic55x-unknown-coff
+tic55x				tic55x-unknown-coff
+tic55x-coff			tic55x-unknown-coff
+tic55x-none-coff		tic55x-none-coff
+tic55x-unknown-coff		tic55x-unknown-coff
+c6x				tic6x-unknown-coff
+c6x-coff			tic6x-unknown-coff
+c6x-none-coff			tic6x-none-coff
+c6x-unknown-coff		tic6x-unknown-coff
+c6x-elf				tic6x-unknown-elf
+c6x-none-elf			tic6x-none-elf
+c6x-unknown-elf			tic6x-unknown-elf
+c6x-uclinux			tic6x-unknown-uclinux
+tic6x				tic6x-unknown-coff
+tic6x-coff			tic6x-unknown-coff
+tic6x-none-coff			tic6x-none-coff
+tic6x-unknown-coff		tic6x-unknown-coff
+tic6x-elf			tic6x-unknown-elf
+tic6x-none-elf			tic6x-none-elf
+tic6x-unknown-elf		tic6x-unknown-elf
+tic6x-uclinux			tic6x-unknown-uclinux