From 508141355c24fe58f796868bc5f54ccbf01d3b9a Mon Sep 17 00:00:00 2001 From: Changpeng Fang Date: Wed, 9 Jun 2010 22:56:08 +0000 Subject: [PATCH] Limit non-constant step prefetching only to the innermost loops. 2010-06-09 Changpeng Fang * tree-ssa-loop-prefetch.c (gather_memory_references_ref): Do not the gather memory reference in the outer loop if the step is not a constant. From-SVN: r160515 --- gcc/ChangeLog | 6 ++++++ gcc/tree-ssa-loop-prefetch.c | 4 ++++ 2 files changed, 10 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 960d11c8795..2059c936c17 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2010-06-09 Changpeng Fang + + * tree-ssa-loop-prefetch.c (gather_memory_references_ref): + Do not the gather memory reference in the outer loop if the step + is not a constant. + 2010-06-09 Changpeng Fang * tree-ssa-loop-prefetch.c (PREFETCH_MOD_TO_UNROLL_FACTOR_RATIO) : diff --git a/gcc/tree-ssa-loop-prefetch.c b/gcc/tree-ssa-loop-prefetch.c index 705ee81b9c8..8097124bc7f 100644 --- a/gcc/tree-ssa-loop-prefetch.c +++ b/gcc/tree-ssa-loop-prefetch.c @@ -513,6 +513,10 @@ gather_memory_references_ref (struct loop *loop, struct mem_ref_group **refs, if (step == NULL_TREE) return false; + /* Limit non-constant step prefetching only to the innermost loops. */ + if (!cst_and_fits_in_hwi (step) && loop->inner != NULL) + return false; + /* Now we know that REF = &BASE + STEP * iter + DELTA, where DELTA and STEP are integer constants. */ agrp = find_or_create_group (refs, base, step); -- 2.30.2