https://gcc.gnu.org/g:ad20ad7dddcb052429346ae5f94b4a603925084a
commit r15-1648-gad20ad7dddcb052429346ae5f94b4a603925084a
Author: Andre Vieira <andre.simoesdiasvie...@arm.com>
Date: Wed Jun 26 11:07:01 2024 +0100
arm: make arm_predict_doloop_p reject loops with calls
With the introduction of low overhead loops we defined arm_predict_doloop_p,
this is meant to be a low-weight check to rule out loops we are not
considering
for doloop optimization and it is used by other passes to prevent
optimizations
that may hurt the doloop optimization later on. The reason these are meant
to be
lightweight is because it's used by pre-RTL optimizations, meaning we can't
do
the same checks that doloop does.
After the definition of arm_predict_doloop_p, when testing for
armv8.1-m.main,
tree-ssa/ivopts-3.c failed the scan-dump check as the dump now matched an
extra
'!= 0' introduced by:
Doloop cmp iv use: if (ivtmp_1 != 0)
Predict loop 1 can perform doloop optimization later.
where previously we had:
Predict doloop failure due to target specific checks.
and after this patch:
Predict doloop failure due to call in loop.
Predict doloop failure due to target specific checks.
Added a copy of the original tree-ssa/ivopts-3.c as a target specifc test to
check for the new dump message.
gcc/ChangeLog:
* config/arm/arm.cc (arm_predict_doloop_p): Reject loops with
function
calls that are not builtins.
gcc/testsuite/ChangeLog:
* gcc.target/arm/mve/ivopts-3.c: New test.
Diff:
---
gcc/config/arm/arm.cc | 16 ++++++++++++++++
gcc/testsuite/gcc.target/arm/mve/ivopts-3.c | 13 +++++++++++++
2 files changed, 29 insertions(+)
diff --git a/gcc/config/arm/arm.cc b/gcc/config/arm/arm.cc
index 7d67d2cfee9..6dab65f493b 100644
--- a/gcc/config/arm/arm.cc
+++ b/gcc/config/arm/arm.cc
@@ -35587,6 +35587,22 @@ arm_predict_doloop_p (struct loop *loop)
" loop bb complexity.\n");
return false;
}
+ else
+ {
+ gimple_stmt_iterator gsi = gsi_after_labels (loop->header);
+ while (!gsi_end_p (gsi))
+ {
+ if (is_gimple_call (gsi_stmt (gsi))
+ && !gimple_call_builtin_p (gsi_stmt (gsi)))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Predict doloop failure due to"
+ " call in loop.\n");
+ return false;
+ }
+ gsi_next (&gsi);
+ }
+ }
return true;
}
diff --git a/gcc/testsuite/gcc.target/arm/mve/ivopts-3.c
b/gcc/testsuite/gcc.target/arm/mve/ivopts-3.c
new file mode 100644
index 00000000000..19b2442ef12
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/mve/ivopts-3.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-ivopts-details" } */
+
+void f2 (void);
+
+int main (void)
+{
+ int i;
+ for (i = 0; i < 10; i++)
+ f2 ();
+}
+
+/* { dg-final { scan-tree-dump "Predict doloop failure due to call in loop."
"ivopts" } } */
