On 2/27/24 13:30, Greg McGary wrote:
On 2/27/24 8:25 AM, Jeff Law wrote:
On 2/25/24 21:53, Greg McGary wrote:
Add option -m(no-)autovec-segment to enable/disable autovectorizer
from emitting vector segment load/store instructions. This is useful for
performance experiments.
gcc/ChangeLog:
* config/riscv/autovec.md (vec_mask_len_load_lanes,
vec_mask_len_store_lanes):
Predicate with TARGET_VECTOR_AUTOVEC_SEGMENT
* gcc/config/riscv/riscv-opts.h (TARGET_VECTOR_AUTOVEC_SEGMENT):
New macro.
* gcc/config/riscv/riscv.opt (-m(no-)autovec-segment): New option.
* gcc/tree-vect-stmts.cc (gcc/tree-vect-stmts.cc): Prevent
divide-by-zero.
* testsuite/gcc.target/riscv/rvv/autovec/struct/*_noseg*.c,
testsuite/gcc.target/riscv/rvv/autovec/no-segment.c: New tests.
I don't mind having options to do this kind of selection (we've done
similar things internally for other RVV features). But I don't think
now is the time to be introducing this stuff. We're in stage4 of the
development cycle after all.
No problemo. Will you take the simple bugfix?
gcc/tree-vect-stmts.cc (gcc/tree-vect-stmts.cc): Prevent divide-by-zero.
diff --git a/gcc/tree-vect-stmts.cc b/gcc/tree-vect-stmts.cc
index 1dbe1115da4..6303d82d959 100644
--- a/gcc/tree-vect-stmts.cc
+++ b/gcc/tree-vect-stmts.cc
@@ -11521,7 +11521,8 @@ vectorizable_load (vec_info *vinfo,
- (vec_num * j + i) * nunits);
/* remain should now be > 0 and < nunits. */
unsigned num;
- if (constant_multiple_p (nunits, remain, &num))
+ if (known_gt (remain, 0)
+ && constant_multiple_p (nunits, remain, &num))
{
tree ptype;
new_vtype
I am unaware of a testcase that triggers it without disabling segmented
load, so LMK if you are cool with the fix without a test case.
We'd really need a testcase and some analysis -- this change will affect
every target, so you'd need to explain why the change is correct.
jeff
