tree-optimization/106533 - loop distribution of inner loop of nest
Commit Message
Loop distribution currently gives up if the outer loop of a loop
nest it analyzes contains a stmt with side-effects instead of
continuing to analyze the innermost loop. The following fixes that
by continuing anyway.
Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed.
PR tree-optimization/106533
* tree-loop-distribution.cc (loop_distribution::execute): Continue
analyzing the inner loops when find_seed_stmts_for_distribution
fails.
* gcc.dg/tree-ssa/ldist-39.c: New testcase.
---
gcc/testsuite/gcc.dg/tree-ssa/ldist-39.c | 16 ++++++++++++++++
gcc/tree-loop-distribution.cc | 2 +-
2 files changed, 17 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/ldist-39.c
new file mode 100644
@@ -0,0 +1,16 @@
+/* PR/106533 */
+/* { dg-options "-O2 -fdump-tree-ldist-optimized" } */
+
+void bar (int *a, int * __restrict b)
+{
+ for (int k = 0; k < 10; k++)
+ {
+ for (int j = 0; j < 100000; ++j)
+ a[j] = b[j];
+ __builtin_printf ("Foo!");
+ }
+}
+
+/* The stmt with side-effects in the outer loop should not prevent
+ distribution of the inner loop of the loop nest. */
+/* { dg-final { scan-tree-dump "optimized: Loop . distributed: split to 0 loops and 1 library calls" "ldist" } } */
@@ -3829,7 +3829,7 @@ loop_distribution::execute (function *fun)
{
auto_vec<gimple *> work_list;
if (!find_seed_stmts_for_distribution (loop, &work_list))
- break;
+ continue;
const char *str = loop->inner ? " nest" : "";
dump_user_location_t loc = find_loop_location (loop);