From patchwork Wed Aug 11 17:36:42 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [PR, 45241] : CPU2006 465.tonto ICE in the vectorizer with -fno-tree-pre From: "Fang, Changpeng" X-Patchwork-Id: 61494 Message-Id: To: Ira Rosen , "gcc-patches@gcc.gnu.org" Date: Wed, 11 Aug 2010 12:36:42 -0500 Hi, Attached patch fixes bug 45241: CPU2006 465.tonto ICE in the vectorizer with -fno-tree-pre. When the vectorizer tries to recognize the dot_prod pattern, it traces the statements chain outside the loop. As a result, ICE occurs when it tries to access the stmt_vinfo for a stmt outside the loop. This patch stops the pattern searching when the statement is already outside the loop. It passed bootstrapping in both the trunk and 4.5 branch. The bug is 4.5/4.6 regression, and it prevents benchmarking for cpu2006 with no PRE. Is it OK to commit to 4,5 branch (and 4.6 ? Thanks, Changpeng >From c13c752b77704e04b8285fb667d6f01f95352136 Mon Sep 17 00:00:00 2001 From: Changpeng Fang Date: Tue, 10 Aug 2010 15:31:20 -0700 Subject: [PATCH] pr45241 give up dot_prod pattern searching if stmt is outside the loop * gcc/tree-vect-patterns.c (vect_recog_dot_prod_pattern): Give up dor_prod pattern searching if a stmt is outside the loop. * gcc.dg/vect/pr45241.c: New. --- gcc/testsuite/gcc.dg/vect/pr45241.c | 19 +++++++++++++++++++ gcc/tree-vect-patterns.c | 5 +++++ 2 files changed, 24 insertions(+), 0 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/vect/pr45241.c diff --git a/gcc/testsuite/gcc.dg/vect/pr45241.c b/gcc/testsuite/gcc.dg/vect/pr45241.c new file mode 100644 index 0000000..c04cf04 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/pr45241.c @@ -0,0 +1,19 @@ +/* PR tree-optimization/45241 */ +/* { dg-do compile } */ +/* { dg-options "-O3 -ftree-pre" } */ + +int +foo (short x) +{ + short i, y; + int sum; + + for (i = 0; i < x; i++) + y = x * i; + + for (i = x; i > 0; i--) + sum += y; + + return sum; +} + diff --git a/gcc/tree-vect-patterns.c b/gcc/tree-vect-patterns.c index 19f0ae6..19df13f 100644 --- a/gcc/tree-vect-patterns.c +++ b/gcc/tree-vect-patterns.c @@ -255,6 +255,11 @@ vect_recog_dot_prod_pattern (gimple last_stmt, tree *type_in, tree *type_out) prod_type = half_type; stmt = SSA_NAME_DEF_STMT (oprnd0); + + /* It could not be the dot_prod pattern if the stmt is outside the loop. */ + if (!flow_bb_inside_loop_p (loop, gimple_bb (stmt))) + return NULL; + /* FORNOW. Can continue analyzing the def-use chain when this stmt in a phi inside the loop (in case we are analyzing an outer-loop). */ if (!is_gimple_assign (stmt)) -- 1.6.3.3