------- Comment #4 from kkojima at gcc dot gnu dot org 2009-05-13 14:07 -------
Created an attachment (id=17857)
--> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=17857&action=view)
a test case
I've got a small test case from libiberty/concat.c.
With -O1, 4.3 compiles vconcat_length to the codes below:
...
.L5:
jsr @r12 ! Call strlen
nop
add r0,r9
mov.l @r8,r4
mov r4,r2
add #4,r2
mov.l @(4,r8),r1
cmp/hs r2,r1
bt/s .L4
mov r8,r2
mov.l @(16,r8),r4
mov r13,r2
.L4:
mov r4,r1
add #4,r1
mov.l r1,@r2
mov.l @r4,r4
tst r4,r4
bf/s .L5
mov r9,r4 !!!
mov.l .L17,r0
jsr @r0 ! Call malloc.
...
i.e. the delayed branch optimization fills a delay slot
with an inappropriate instruction at the line !!!.
I've confirmed that the 4.4 compiler's output is similar
and the outputs for 4.2 and 4.5 look correct even with -O.
I have no idea for what is going on ATM, though.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40105
