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

	Backport from 2011-05-30 4.6-branch r174427.
	PR target/45263
	* config/avr/libgcc.S (__do_global_ctors, __do_global_dtors):
	Don't use r20 around calls of __tablejump_elpm__

From-SVN: r187058

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 994658fdaf5a9b8ac6ba3ea7086986d6ed735cd1..ae5c76c90a9850cba5a937b7d9b2a6cb2de89e06 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,11 @@
+2012-05-02  Georg-Johann Lay  <avr@gjlay.de>
+
+       Backport from 2011-05-30 4.6-branch r174427.
+
+       PR target/45263
+       * config/avr/libgcc.S (__do_global_ctors, __do_global_dtors):
+       Don't use r20 around calls of __tablejump_elpm__
+
 2012-05-02  Georg-Johann Lay  <avr@gjlay.de>
 
        Backport from 2011-07-11 4.6-branch r176143

diff --git a/gcc/config/avr/libgcc.S b/gcc/config/avr/libgcc.S
index 07a50b20e310048b138af38fc0401ecec789c706..571a0243de2017f503b2fe73e57e95c234350317 100644 (file)
--- a/gcc/config/avr/libgcc.S
+++ b/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: