From fa8e5051889f8bc0610e3400152b73755d12d04e Mon Sep 17 00:00:00 2001 From: Ilya Enkovich Date: Wed, 28 Jan 2015 11:41:40 +0000 Subject: [PATCH] re PR tree-optimization/64277 (Incorrect warning "array subscript is above array bounds") gcc/ PR tree-optimization/64277 * tree-ssa-loop-niter.c (record_nonwrapping_iv): Use base range info when possible to refine estimation. gcc/testsuite/ PR tree-optimization/64277 * gcc.dg/pr64277.c: New. From-SVN: r220204 --- gcc/ChangeLog | 6 ++++++ gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/pr64277.c | 23 +++++++++++++++++++++++ gcc/tree-ssa-loop-niter.c | 19 +++++++++++++++++-- 4 files changed, 51 insertions(+), 2 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/pr64277.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 71413471372..61b36b1b28d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2015-01-28 Ilya Enkovich + + PR tree-optimization/64277 + * tree-ssa-loop-niter.c (record_nonwrapping_iv): Use base + range info when possible to refine estimation. + 2015-01-28 Thomas Preud'homme PR tree-optimization/64718 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 4f4e72ca9f7..6a6a245b728 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2015-01-28 Ilya Enkovich + + PR tree-optimization/64277 + * gcc.dg/pr64277.c: New. + 2015-01-28 Thomas Preud'homme PR tree-optimization/64718 diff --git a/gcc/testsuite/gcc.dg/pr64277.c b/gcc/testsuite/gcc.dg/pr64277.c new file mode 100644 index 00000000000..c6ef33119a7 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr64277.c @@ -0,0 +1,23 @@ +/* PR tree-optimization/64277 */ +/* { dg-do compile } */ +/* { dg-options "-O3 -Wall -Werror -fdump-tree-cunroll-details" } */ +/* { dg-final { scan-tree-dump "loop with 5 iterations completely unrolled" "cunroll" } } */ +/* { dg-final { scan-tree-dump "loop with 6 iterations completely unrolled" "cunroll" } } */ +/* { dg-final { cleanup-tree-dump "cunroll" } } */ + +int f1[10]; +void test1 (short a[], short m, unsigned short l) +{ + int i = l; + for (i = i + 5; i < m; i++) + f1[i] = a[i]++; +} + +void test2 (short a[], short m, short l) +{ + int i; + if (m > 5) + m = 5; + for (i = m; i > l; i--) + f1[i] = a[i]++; +} diff --git a/gcc/tree-ssa-loop-niter.c b/gcc/tree-ssa-loop-niter.c index 919f5c0d8f2..a6779585b79 100644 --- a/gcc/tree-ssa-loop-niter.c +++ b/gcc/tree-ssa-loop-niter.c @@ -2754,6 +2754,7 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple stmt, { tree niter_bound, extreme, delta; tree type = TREE_TYPE (base), unsigned_type; + tree orig_base = base; if (TREE_CODE (step) != INTEGER_CST || integer_zerop (step)) return; @@ -2777,16 +2778,30 @@ record_nonwrapping_iv (struct loop *loop, tree base, tree step, gimple stmt, if (tree_int_cst_sign_bit (step)) { + wide_int min, max; extreme = fold_convert (unsigned_type, low); - if (TREE_CODE (base) != INTEGER_CST) + if (TREE_CODE (orig_base) == SSA_NAME + && TREE_CODE (high) == INTEGER_CST + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base)) + && get_range_info (orig_base, &min, &max) == VR_RANGE + && wi::gts_p (high, max)) + base = wide_int_to_tree (unsigned_type, max); + else if (TREE_CODE (base) != INTEGER_CST) base = fold_convert (unsigned_type, high); delta = fold_build2 (MINUS_EXPR, unsigned_type, base, extreme); step = fold_build1 (NEGATE_EXPR, unsigned_type, step); } else { + wide_int min, max; extreme = fold_convert (unsigned_type, high); - if (TREE_CODE (base) != INTEGER_CST) + if (TREE_CODE (orig_base) == SSA_NAME + && TREE_CODE (low) == INTEGER_CST + && INTEGRAL_TYPE_P (TREE_TYPE (orig_base)) + && get_range_info (orig_base, &min, &max) == VR_RANGE + && wi::gts_p (min, low)) + base = wide_int_to_tree (unsigned_type, min); + else if (TREE_CODE (base) != INTEGER_CST) base = fold_convert (unsigned_type, low); delta = fold_build2 (MINUS_EXPR, unsigned_type, extreme, base); } -- 2.30.2