http://gcc.gnu.org/bugzilla/show_bug.cgi?id=18557
Richard Guenther <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |RESOLVED
Resolution| |DUPLICATE
--- Comment #13 from Richard Guenther <rguenth at gcc dot gnu.org> 2012-07-13
13:52:25 UTC ---
At -O3 we now get calls to memset for the original testcase, changing it to
store 1 instead we get
$f..ng:
f:
.frame $30,0,$26,0
.prologue 0
and $16,4,$1
cmpult $31,$1,$1
lda $7,64($31)
addl $31,$1,$2
mov $31,$22
beq $2,$L2
lda $7,63($31)
lda $22,1($31)
lda $3,1($31)
stl $3,0($16)
$L2:
lda $3,64($31)
subl $3,$2,$2
zapnot $2,15,$8
lda $5,1($31)
srl $8,1,$6
sll $5,32,$5
addl $6,$6,$2
s4addq $1,$16,$1
mov $31,$3
zapnot $6,15,$6
lda $5,1($5)
.align 4
$L6:
addl $3,1,$3
stq $5,0($1)
zapnot $3,15,$4
lda $1,8($1)
cmpult $4,$6,$4
bne $4,$L6
zapnot $2,15,$3
addl $22,$2,$1
cmpeq $8,$3,$8
cpys $f31,$f31,$f31
subl $7,$2,$2
bne $8,$L8
s4addq $1,0,$1
lda $4,1($31)
.align 4
$L5:
addq $16,$1,$3
subl $2,1,$2
stl $4,0($3)
lda $1,4($1)
bne $2,$L5
$L8:
ret $31,($26),1
.end f
which seems to be reasonable. We still run into the issue that we do
not recognize that the epilogue loop may at most iterate once. The
vectorizer makes a mess out of induction variables for the prologue/epilogue
loops. See PR53355 for where I track this general issue.
*** This bug has been marked as a duplicate of bug 53355 ***
