Hi
I was fiddling around with the loop unrolling pass and noticed a check
in decide_unroll_* functions (in the patch). The comment on top of this
check says
"/* If we were not asked to unroll this loop, just return back silently.
*/"
However the check returns when loop->unroll == 0 rather than 1.
The check was added in r255106 where the ChangeLog suggests that the
actual intention was probably to check the value 1 and not 0.
Tested on aarch64-none-elf with one new regression:
FAIL: gcc.dg/pr40209.c (test for excess errors)
This fails because the changes cause the loop to unroll 3 times using
unroll_stupid and that shows up as excess error due -fopt-info. This
option was added in r202077 but I am not sure why this particular test
was chosen for it.
Does this change look ok? Can I just remove the -fopt-info from the test
or unrolling the loop in the test is not desirable?
Thanks
Sudi
gcc/ChangeLog:
2019-11-07 Sudakshina Das <sudi....@arm.com>
* loop-unroll.c (decide_unroll_constant_iterations): Update condition
to check
loop->unroll.
(decide_unroll_runtime_iterations): Likewise.
(decide_unroll_stupid): Likewise.
diff --git a/gcc/loop-unroll.c b/gcc/loop-unroll.c
index 63fccd23fae38f8918a7d94411aaa43c72830dd3..9f7ab4b5c1c9b2333148e452b84afbf040707456 100644
--- a/gcc/loop-unroll.c
+++ b/gcc/loop-unroll.c
@@ -354,7 +354,7 @@ decide_unroll_constant_iterations (class loop *loop, int flags)
widest_int iterations;
/* If we were not asked to unroll this loop, just return back silently. */
- if (!(flags & UAP_UNROLL) && !loop->unroll)
+ if (!(flags & UAP_UNROLL) && loop->unroll == 1)
return;
if (dump_enabled_p ())
@@ -674,7 +674,7 @@ decide_unroll_runtime_iterations (class loop *loop, int flags)
widest_int iterations;
/* If we were not asked to unroll this loop, just return back silently. */
- if (!(flags & UAP_UNROLL) && !loop->unroll)
+ if (!(flags & UAP_UNROLL) && loop->unroll == 1)
return;
if (dump_enabled_p ())
@@ -1159,7 +1159,7 @@ decide_unroll_stupid (class loop *loop, int flags)
widest_int iterations;
/* If we were not asked to unroll this loop, just return back silently. */
- if (!(flags & UAP_UNROLL_ALL) && !loop->unroll)
+ if (!(flags & UAP_UNROLL_ALL) && loop->unroll == 1)
return;
if (dump_enabled_p ())
