From 51bd28edcbf49844d696c38af4945ce5fc25ba15 Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 8 Aug 2017 12:51:20 +0000 Subject: [PATCH] re PR middle-end/81719 (Range-based for loop on short fixed size array generates long unrolled loop) 2017-08-08 Richard Biener PR middle-end/81719 * tree-ssa-loop-niter.c: Include tree-dfa.h. (expand_simple_operations): Also look through ADDR_EXPRs with MEM_REF bases treating them as POINTER_PLUS_EXPR. * g++.dg/tree-ssa/pr81719.C: New testcase. From-SVN: r250954 --- gcc/ChangeLog | 7 +++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/g++.dg/tree-ssa/pr81719.C | 24 ++++++++++++++++++++++++ gcc/tree-ssa-loop-niter.c | 16 ++++++++++++++++ 4 files changed, 52 insertions(+) create mode 100644 gcc/testsuite/g++.dg/tree-ssa/pr81719.C diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c88e6668c9e..b0a59d55164 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2017-08-08 Richard Biener + + PR middle-end/81719 + * tree-ssa-loop-niter.c: Include tree-dfa.h. + (expand_simple_operations): Also look through ADDR_EXPRs with + MEM_REF bases treating them as POINTER_PLUS_EXPR. + 2017-08-08 Richard Biener PR tree-optimization/81723 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index a3f5d46ed7d..1fec0ec1152 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-08-08 Richard Biener + + PR middle-end/81719 + * g++.dg/tree-ssa/pr81719.C: New testcase. + 2017-08-08 Richard Biener PR tree-optimization/81723 diff --git a/gcc/testsuite/g++.dg/tree-ssa/pr81719.C b/gcc/testsuite/g++.dg/tree-ssa/pr81719.C new file mode 100644 index 00000000000..6e017afbae2 --- /dev/null +++ b/gcc/testsuite/g++.dg/tree-ssa/pr81719.C @@ -0,0 +1,24 @@ +/* { dg-do compile { target c++11 } } */ +/* { dg-options "-O3 -fdump-tree-optimized" } */ + +typedef int Items[2]; + +struct ItemArray +{ + Items items; + int sum_x2() const; +}; + +int ItemArray::sum_x2() const +{ + int total = 0; + for (int item : items) + { + total += item; + } + return total; +} + +/* We should be able to compute the number of iterations to two, unroll + the loop and end up with a single basic-block in sum_x2. */ +/* { dg-final { scan-tree-dump-times "bb" 1 "optimized" } } */ diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index e0107c28dfb..0d6d1019ac6 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -42,6 +42,7 @@ along with GCC; see the file COPYING3. If not see #include "tree-chrec.h" #include "tree-scalar-evolution.h" #include "params.h" +#include "tree-dfa.h" /* The maximum number of dominator BBs we search for conditions @@ -1980,6 +1981,21 @@ expand_simple_operations (tree expr, tree stop) if (code == SSA_NAME) return expand_simple_operations (e, stop); + else if (code == ADDR_EXPR) + { + HOST_WIDE_INT offset; + tree base = get_addr_base_and_unit_offset (TREE_OPERAND (e, 0), + &offset); + if (base + && TREE_CODE (base) == MEM_REF) + { + ee = expand_simple_operations (TREE_OPERAND (base, 0), stop); + return fold_build2 (POINTER_PLUS_EXPR, TREE_TYPE (expr), ee, + wide_int_to_tree (sizetype, + mem_ref_offset (base) + + offset)); + } + } return expr; } -- 2.30.2