Jiufu Guo <guoji...@linux.ibm.com> writes:
> Richard Biener <rguent...@suse.de> writes:
>
>> On Wed, 11 Nov 2020, Jiufu Guo wrote:
>>
>>>
>>> Thanks a lot for the suggestion from previous mails.
>>> The patch was updated accordingly.
>>>
>>> This updated patch propagates loop-closed PHIs them out after
>>> loop_optimizer_finalize under a new introduced flag. At some cases,
>>> to clean up loop-closed PHIs would save efforts of optimization passes
>>> after loopdone.
>>>
>>> This patch passes bootstrap and regtest on ppc64le. Is this ok for trunk?
>>
>> Comments below
>>
>>> free_numbers_of_iterations_estimates (fn);
>>>
>>> + if (flag_clean_up_loop_closed_phi
>>
>> Sorry if there was miscommunication but I've not meant to add a
>> new user-visible flag but instead a flag argument to loop_optimizer_finalize
>> (as said, you can default it to false to only need to change the
>> one in fini_loops)
> Sorry for misunderstand.
> Updated the patch.
Thanks for the comments! The patch was updated accordingly.
This updated patch clean up loop closed PHIs in
loop_optimizer_finalize,
which is called when some loop optimizations are done. For some cases,
this would save efforts of optimization passes after loopdone.
gcc/ChangeLog:
2020-10-16 Jiufu Guo <guoji...@linux.ibm.com>
* cfgloop.h (loop_optimizer_finalize): Add flag argument.
* loop-init.c (loop_optimizer_finalize): Call
clean_up_loop_closed_phi.
* tree-cfgcleanup.h (clean_up_loop_closed_phi): New declare.
* tree-ssa-loop.c (tree_ssa_loop_done): Call
loop_optimizer_finalize
with flag argument.
* tree-ssa-propagate.c (clean_up_loop_closed_phi): New
function.
gcc/testsuite/ChangeLog:
2020-10-16 Jiufu Guo <guoji...@linux.ibm.com>
* gcc.dg/tree-ssa/loopclosedphi.c: New test.
---
gcc/cfgloop.h | 2 +-
gcc/loop-init.c | 9 ++-
gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c | 21 +++++++
gcc/tree-cfgcleanup.h | 1 +
gcc/tree-ssa-loop.c | 2 +-
gcc/tree-ssa-propagate.c | 63
+++++++++++++++++++
6 files changed, 95 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c
diff --git a/gcc/cfgloop.h b/gcc/cfgloop.h
index d14689dc31f..438b1f779bb 100644
--- a/gcc/cfgloop.h
+++ b/gcc/cfgloop.h
@@ -824,7 +824,7 @@ extern void init_set_costs (void);
/* Loop optimizer initialization. */
extern void loop_optimizer_init (unsigned);
-extern void loop_optimizer_finalize (function *);
+extern void loop_optimizer_finalize (function *, bool = false);
inline void
loop_optimizer_finalize ()
{
diff --git a/gcc/loop-init.c b/gcc/loop-init.c
index 401e5282907..0cb6f509b89 100644
--- a/gcc/loop-init.c
+++ b/gcc/loop-init.c
@@ -33,6 +33,7 @@ along with GCC; see the file COPYING3. If not see
#include "tree-ssa-loop-niter.h"
#include "loop-unroll.h"
#include "tree-scalar-evolution.h"
+#include "tree-cfgcleanup.h"
/* Apply FLAGS to the loop state. */
@@ -133,7 +134,7 @@ loop_optimizer_init (unsigned flags)
/* Finalize loop structures. */
void
-loop_optimizer_finalize (struct function *fn)
+loop_optimizer_finalize (struct function *fn, bool
clean_loop_closed_phi)
{
class loop *loop;
basic_block bb;
@@ -145,6 +146,12 @@ loop_optimizer_finalize (struct function *fn)
free_numbers_of_iterations_estimates (fn);
+ if (clean_loop_closed_phi && loops_state_satisfies_p (fn,
LOOP_CLOSED_SSA))
+ {
+ clean_up_loop_closed_phi (fn);
+ loops_state_clear (fn, LOOP_CLOSED_SSA);
+ }
+
/* If we should preserve loop structure, do not free it but clear
flags that advanced properties are there as we are not
preserving
that in full. */
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c
b/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c
new file mode 100644
index 00000000000..d71b757fbca
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/loopclosedphi.c
@@ -0,0 +1,21 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fno-tree-ch -w -fdump-tree-loopdone-details" }
*/
+
+void
+t6 (int qz, int wh)
+{
+ int jl = wh;
+
+ while (1.0 * qz / wh < 1)
+ {
+ qz = wh * (wh + 2);
+
+ while (wh < 1)
+ jl = 0;
+ }
+
+ while (qz < 1)
+ qz = jl * wh;
+}
+
+/* { dg-final { scan-tree-dump-times "Replacing" 2 "loopdone"} } */
diff --git a/gcc/tree-cfgcleanup.h b/gcc/tree-cfgcleanup.h
index 6ff6726bfe4..9e368d63709 100644
--- a/gcc/tree-cfgcleanup.h
+++ b/gcc/tree-cfgcleanup.h
@@ -26,5 +26,6 @@ extern bool cleanup_tree_cfg (unsigned = 0);
extern bool fixup_noreturn_call (gimple *stmt);
extern bool delete_unreachable_blocks_update_callgraph (cgraph_node
*dst_node,
bool
update_clones);
+extern unsigned clean_up_loop_closed_phi (function *);
#endif /* GCC_TREE_CFGCLEANUP_H */
diff --git a/gcc/tree-ssa-loop.c b/gcc/tree-ssa-loop.c
index 5e8365d4e83..339a0c50bc8 100644
--- a/gcc/tree-ssa-loop.c
+++ b/gcc/tree-ssa-loop.c
@@ -529,7 +529,7 @@ tree_ssa_loop_done (void)
{
free_numbers_of_iterations_estimates (cfun);
scev_finalize ();
- loop_optimizer_finalize ();
+ loop_optimizer_finalize (cfun, true);
return 0;
}
diff --git a/gcc/tree-ssa-propagate.c b/gcc/tree-ssa-propagate.c
index 87dbf55fab9..daa1db82afc 100644
--- a/gcc/tree-ssa-propagate.c
+++ b/gcc/tree-ssa-propagate.c
@@ -1549,3 +1549,66 @@ propagate_tree_value_into_stmt
(gimple_stmt_iterator *gsi, tree val)
else
gcc_unreachable ();
}
+
+/* Check exits of each loop in FUN, walk over loop closed PHIs in
+ each exit basic block and propagate degenerate PHIs. */
+
+unsigned
+clean_up_loop_closed_phi (function *fun)
+{
+ unsigned i;
+ edge e;
+ gphi *phi;
+ tree rhs;
+ tree lhs;
+ gphi_iterator gsi;
+ struct loop *loop;
+
+ /* Check dominator info before get loop-close PHIs from loop exits.
*/
+ if (dom_info_state (CDI_DOMINATORS) != DOM_OK)
