Hi Bernd,
It's easy to reproduce this error:
step1: Build gcc for c6x from gcc code of latest trunk, say
c6x-uclinux-gcc for example
step2: Using the newly built c6x gcc compiler to comiple this small case:
$c6x-unlinux-gcc -S -O2 arraysum.c
arraysum.c:
int array[1024];
int test_entry ()
{
unsigned int i;
int sum = 0;
for (i = 0; i < 1024; i++) {
sum = sum + array[i];
}
return sum;
}
Note: -freorder-blocks is enable under -O2.
I think it would be better to skip reorder_loops if bb reordering is
enabled, since function without hw-doloops
can still benefit from block reordering optimization.
Attached please find the updated patch. Please apply it if OK for trunk. Thanks
Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog (revision 206280)
+++ gcc/ChangeLog (working copy)
@@ -1,3 +1,9 @@
+2014-01-02 Felix Yang <fei.yang0...@gmail.com>
+
+ * config/c6x/c6x.c (c6x_hwloops): Do not reorder loop's basic blocks
+ if bb reordering is enabled.
+ * config/bfin/bfin.c (bfin_reorg_loops): Ditto.
+
2014-01-01 Jan-Benedict Glaw <jbg...@lug-owl.de>
* config/nios2/nios2.h (BITS_PER_UNIT): Don't define it.
Index: gcc/config/c6x/c6x.c
===================================================================
--- gcc/config/c6x/c6x.c (revision 206280)
+++ gcc/config/c6x/c6x.c (working copy)
@@ -5895,7 +5895,15 @@ static void
c6x_hwloops (void)
{
if (optimize)
- reorg_loops (true, &c6x_doloop_hooks);
+ {
+ /* Do not reorder loop's basic blocks if bb reordering is
enabled. The reason
+ is that cfg layout mode should not be re-entered once bb reordering is
+ complete. */
+ if (flag_reorder_blocks || flag_reorder_blocks_and_partition)
+ reorg_loops (false, &c6x_doloop_hooks);
+ else
+ reorg_loops (true, &c6x_doloop_hooks);
+ }
}
/* Implement the TARGET_MACHINE_DEPENDENT_REORG pass. We split call insns here
Index: gcc/config/bfin/bfin.c
===================================================================
--- gcc/config/bfin/bfin.c (revision 206280)
+++ gcc/config/bfin/bfin.c (working copy)
@@ -3885,7 +3885,13 @@ static struct hw_doloop_hooks bfin_doloop_hooks =
static void
bfin_reorg_loops (void)
{
- reorg_loops (true, &bfin_doloop_hooks);
+ /* Do not reorder loop's basic blocks if bb reordering is enabled. The reason
+ is that cfg layout mode should not be re-entered once bb reordering is
+ complete. */
+ if (flag_reorder_blocks || flag_reorder_blocks_and_partition)
+ reorg_loops (false, &bfin_doloop_hooks);
+ else
+ reorg_loops (true, &bfin_doloop_hooks);
}
/* Possibly generate a SEQUENCE out of three insns found in SLOT.
Cheers,
Felix
On Thu, Jan 2, 2014 at 7:04 PM, Bernd Schmidt <ber...@codesourcery.com> wrote:
> On 01/01/2014 02:01 PM, Felix Yang wrote:
>>
>> cc1 backtrace:
>>
>> arraysum.c: In function 'test_entry':
>> arraysum.c:14:1: internal compiler error: in cfg_layout_initialize, at
>> cfgrtl.c:4233
>
>
> Please include steps to reproduce bugs.
>
>
>> Attached please find the patch for this ICE.
>> Since c6x backend choose doloops whose tail and head are the same
>> block, code generation will not be affected.
>> But it may bring some negetive effect on target code efficiency for
>> bfin backend as less hw-doloops may be generated.
>> In my point of view, what we need here is a better block reordering
>> that cares about hw-doloops.
>> If OK for trunk, can someone please apply it? Thanks.
>
>
> Is this with -freorder-blocks? Rather than delete the code, just skip it if
> that flag is enabled. Or forcibly turn it off for these ports in
> option_override.
>
>
> Bernd
>
Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog (revision 206280)
+++ gcc/ChangeLog (working copy)
@@ -1,3 +1,9 @@
+2014-01-02 Felix Yang <fei.yang0...@gmail.com>
+
+ * config/c6x/c6x.c (c6x_hwloops): Do not reorder loop's basic blocks
+ if bb reordering is enabled.
+ * config/bfin/bfin.c (bfin_reorg_loops): Ditto.
+
2014-01-01 Jan-Benedict Glaw <jbg...@lug-owl.de>
* config/nios2/nios2.h (BITS_PER_UNIT): Don't define it.
Index: gcc/config/c6x/c6x.c
===================================================================
--- gcc/config/c6x/c6x.c (revision 206280)
+++ gcc/config/c6x/c6x.c (working copy)
@@ -5895,7 +5895,15 @@ static void
c6x_hwloops (void)
{
if (optimize)
- reorg_loops (true, &c6x_doloop_hooks);
+ {
+ /* Do not reorder loop's basic blocks if bb reordering is enabled. The
reason
+ is that cfg layout mode should not be re-entered once bb reordering is
+ complete. */
+ if (flag_reorder_blocks || flag_reorder_blocks_and_partition)
+ reorg_loops (false, &c6x_doloop_hooks);
+ else
+ reorg_loops (true, &c6x_doloop_hooks);
+ }
}
/* Implement the TARGET_MACHINE_DEPENDENT_REORG pass. We split call insns here
Index: gcc/config/bfin/bfin.c
===================================================================
--- gcc/config/bfin/bfin.c (revision 206280)
+++ gcc/config/bfin/bfin.c (working copy)
@@ -3885,7 +3885,13 @@ static struct hw_doloop_hooks bfin_doloop_hooks =
static void
bfin_reorg_loops (void)
{
- reorg_loops (true, &bfin_doloop_hooks);
+ /* Do not reorder loop's basic blocks if bb reordering is enabled. The reason
+ is that cfg layout mode should not be re-entered once bb reordering is
+ complete. */
+ if (flag_reorder_blocks || flag_reorder_blocks_and_partition)
+ reorg_loops (false, &bfin_doloop_hooks);
+ else
+ reorg_loops (true, &bfin_doloop_hooks);
}
/* Possibly generate a SEQUENCE out of three insns found in SLOT.
