From 248179b5fc812b294e2488b23fedaaabe099ad9d Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Tue, 4 Apr 2017 09:06:04 +0000 Subject: [PATCH] re PR tree-optimization/80281 (Wrong constant folding) 2017-04-04 Richard Biener PR middle-end/80281 * match.pd (A + (-B) -> A - B): Make sure to preserve unsigned arithmetic done for the negate or the plus. Simplify. (A - (-B) -> A + B): Likewise. * fold-const.c (split_tree): Make sure to not negate pointers. * gcc.dg/torture/pr80281.c: New testcase. From-SVN: r246674 --- gcc/ChangeLog | 8 +++++++ gcc/fold-const.c | 15 ++++++++++--- gcc/match.pd | 30 ++++++++++++++++++-------- gcc/testsuite/ChangeLog | 5 +++++ gcc/testsuite/gcc.dg/torture/pr80281.c | 14 ++++++++++++ 5 files changed, 60 insertions(+), 12 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr80281.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4d113af985d..eceada15c36 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2017-04-04 Richard Biener + + PR middle-end/80281 + * match.pd (A + (-B) -> A - B): Make sure to preserve unsigned + arithmetic done for the negate or the plus. Simplify. + (A - (-B) -> A + B): Likewise. + * fold-const.c (split_tree): Make sure to not negate pointers. + 2017-04-04 Segher Boessenkool PR rtl-optimization/60818 diff --git a/gcc/fold-const.c b/gcc/fold-const.c index d0f1c0685ca..b4c117c8494 100644 --- a/gcc/fold-const.c +++ b/gcc/fold-const.c @@ -831,8 +831,12 @@ split_tree (location_t loc, tree in, tree type, enum tree_code code, /* Now do any needed negations. */ if (neg_litp_p) *minus_litp = *litp, *litp = 0; - if (neg_conp_p) - *conp = negate_expr (*conp); + if (neg_conp_p && *conp) + { + /* Convert to TYPE before negating. */ + *conp = fold_convert_loc (loc, type, *conp); + *conp = negate_expr (*conp); + } if (neg_var_p && var) { /* Convert to TYPE before negating. */ @@ -859,7 +863,12 @@ split_tree (location_t loc, tree in, tree type, enum tree_code code, *minus_litp = *litp, *litp = 0; else if (*minus_litp) *litp = *minus_litp, *minus_litp = 0; - *conp = negate_expr (*conp); + if (*conp) + { + /* Convert to TYPE before negating. */ + *conp = fold_convert_loc (loc, type, *conp); + *conp = negate_expr (*conp); + } if (var) { /* Convert to TYPE before negating. */ diff --git a/gcc/match.pd b/gcc/match.pd index 4e6f7199947..357797877c8 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1148,19 +1148,31 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* Contract negates. */ /* A + (-B) -> A - B */ (simplify - (plus:c (convert1? @0) (convert2? (negate @1))) - /* Apply STRIP_NOPS on @0 and the negate. */ - (if (tree_nop_conversion_p (type, TREE_TYPE (@0)) - && tree_nop_conversion_p (type, TREE_TYPE (@1)) + (plus:c @0 (convert? (negate @1))) + /* Apply STRIP_NOPS on the negate. */ + (if (tree_nop_conversion_p (type, TREE_TYPE (@1)) && !TYPE_OVERFLOW_SANITIZED (type)) - (minus (convert @0) (convert @1)))) + (with + { + tree t1 = type; + if (INTEGRAL_TYPE_P (type) + && TYPE_OVERFLOW_WRAPS (type) != TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1))) + t1 = TYPE_OVERFLOW_WRAPS (type) ? type : TREE_TYPE (@1); + } + (convert (minus (convert:t1 @0) (convert:t1 @1)))))) /* A - (-B) -> A + B */ (simplify - (minus (convert1? @0) (convert2? (negate @1))) - (if (tree_nop_conversion_p (type, TREE_TYPE (@0)) - && tree_nop_conversion_p (type, TREE_TYPE (@1)) + (minus @0 (convert? (negate @1))) + (if (tree_nop_conversion_p (type, TREE_TYPE (@1)) && !TYPE_OVERFLOW_SANITIZED (type)) - (plus (convert @0) (convert @1)))) + (with + { + tree t1 = type; + if (INTEGRAL_TYPE_P (type) + && TYPE_OVERFLOW_WRAPS (type) != TYPE_OVERFLOW_WRAPS (TREE_TYPE (@1))) + t1 = TYPE_OVERFLOW_WRAPS (type) ? type : TREE_TYPE (@1); + } + (convert (plus (convert:t1 @0) (convert:t1 @1)))))) /* -(-A) -> A */ (simplify (negate (convert? (negate @1))) diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 8a88678a4a3..8d7418cd366 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-04-04 Richard Biener + + PR middle-end/80281 + * gcc.dg/torture/pr80281.c: New testcase. + 2017-04-04 Richard Biener PR tree-optimization/80275 diff --git a/gcc/testsuite/gcc.dg/torture/pr80281.c b/gcc/testsuite/gcc.dg/torture/pr80281.c new file mode 100644 index 00000000000..bff4f6e60a8 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr80281.c @@ -0,0 +1,14 @@ +/* { dg-run } */ +/* { dg-require-effective-target int32plus } */ + +int +main () +{ + volatile int a = 0; + long long b = 2147483648LL; + int c = a % 2; + int x = ((int) -b + c) % -2147483647; + if (x != -1) + __builtin_abort (); + return 0; +} -- 2.30.2