From d366015187de926a8fe3248325b229bed99b27b5 Mon Sep 17 00:00:00 2001 From: Bin Cheng Date: Mon, 31 Jul 2017 11:16:44 +0100 Subject: [PATCH 2/2] pr81627-20170731.txt --- gcc/testsuite/gcc.dg/tree-ssa/pr81627.c | 28 ++++++++++++++++++++++++++++ gcc/tree-predcom.c | 10 +++++----- 2 files changed, 33 insertions(+), 5 deletions(-) create mode 100755 gcc/testsuite/gcc.dg/tree-ssa/pr81627.c diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr81627.c b/gcc/testsuite/gcc.dg/tree-ssa/pr81627.c new file mode 100755 index 0000000..7421c49 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr81627.c @@ -0,0 +1,28 @@ +/* { dg-do run } */ +/* { dg-options "-O3 -fno-tree-loop-vectorize -fdump-tree-pcom-details" } */ + +int a, b, c, d[6], e = 3, f; + +void abort (void); +void fn1 () +{ + for (b = 1; b < 5; b++) + { + for (c = 0; c < 5; c++) + d[b] = e; + if (a) + f++; + d[b + 1] = 1; + } +} + +int main () +{ + fn1 (); + if (d[0] != 0 || d[1] != 3 || d[2] != 3 + || d[3] != 3 || d[4] != 3 || d[5] != 1) + abort (); + + return 0; +} +/* { dg-final { scan-tree-dump-times "Store-stores chain" 1 "pcom" } } */ diff --git a/gcc/tree-predcom.c b/gcc/tree-predcom.c index f7a57a4..4538773 100644 --- a/gcc/tree-predcom.c +++ b/gcc/tree-predcom.c @@ -2983,11 +2983,11 @@ prepare_finalizers (struct loop *loop, vec chains) if (prepare_finalizers_chain (loop, chain)) { i++; - /* We don't corrupt loop closed ssa form for store elimination - chain if eliminated stores only store loop invariant values - into memory. */ - if (!chain->inv_store_elimination) - loop_closed_ssa |= (!chain->inv_store_elimination); + /* Be conservative, assume loop closed ssa form is corrupted + by store-store chain. Though it's not always the case if + eliminated stores only store loop invariant values into + memory. */ + loop_closed_ssa = true; } else { -- 1.9.1