re PR target/45263 (registers used in __do_global_ctors can get clobbered)

	PR target/45263
	* config/avr/libgcc.S (__do_global_ctors, __do_global_dtors): Save
	R20 around calls of __tablejump_elpm__

From-SVN: r172384

gcc/ChangeLog

+2011-04-01  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR target/45263
+	* config/avr/libgcc.S (__do_global_ctors, __do_global_dtors): Save
+	R20 around calls of __tablejump_elpm__
+
 2011-04-13  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/48591

gcc/config/avr/libgcc.S

@@ -791,22 +791,22 @@ __do_clear_bss:
 #if defined(__AVR_HAVE_RAMPZ__)
 __do_global_ctors:
 	ldi	r17, hi8(__ctors_start)
-	ldi	r16, hh8(__ctors_start)
 	ldi	r28, lo8(__ctors_end)
 	ldi	r29, hi8(__ctors_end)
-	ldi	r20, hh8(__ctors_end)
+	ldi	r16, hh8(__ctors_end)
 	rjmp	.L__do_global_ctors_start
 .L__do_global_ctors_loop:
 	sbiw	r28, 2
-	sbc     r20, __zero_reg__
+	sbc     r16, __zero_reg__
 	mov_h	r31, r29
 	mov_l	r30, r28
-	out     __RAMPZ__, r20
+	out     __RAMPZ__, r16
 	XCALL	__tablejump_elpm__
 .L__do_global_ctors_start:
 	cpi	r28, lo8(__ctors_start)
 	cpc	r29, r17
-	cpc	r20, r16
+	ldi	r24, hh8(__ctors_start)
+	cpc	r16, r24
 	brne	.L__do_global_ctors_loop
 #else
 __do_global_ctors:
@@ -832,22 +832,22 @@ __do_global_ctors:
 #if defined(__AVR_HAVE_RAMPZ__)
 __do_global_dtors:
 	ldi	r17, hi8(__dtors_end)
-	ldi	r16, hh8(__dtors_end)
 	ldi	r28, lo8(__dtors_start)
 	ldi	r29, hi8(__dtors_start)
-	ldi	r20, hh8(__dtors_start)
+	ldi	r16, hh8(__dtors_start)
 	rjmp	.L__do_global_dtors_start
 .L__do_global_dtors_loop:
 	sbiw	r28, 2
-	sbc     r20, __zero_reg__
+	sbc     r16, __zero_reg__
 	mov_h	r31, r29
 	mov_l	r30, r28
-	out     __RAMPZ__, r20
+	out     __RAMPZ__, r16
 	XCALL	__tablejump_elpm__
 .L__do_global_dtors_start:
 	cpi	r28, lo8(__dtors_end)
 	cpc	r29, r17
-	cpc	r20, r16
+	ldi	r24, hh8(__dtors_end)
+	cpc	r16, r24
 	brne	.L__do_global_dtors_loop
 #else
 __do_global_dtors: