From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1666) id 14E7E380DBE9; Thu, 21 Apr 2022 12:52:04 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 14E7E380DBE9 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Richard Biener To: gcc-cvs@gcc.gnu.org Subject: [gcc r10-10549] middle-end/100786 - constant folding from incompatible alias X-Act-Checkin: gcc X-Git-Author: Richard Biener X-Git-Refname: refs/heads/releases/gcc-10 X-Git-Oldrev: 4ed8728e2646897c98826cf43be2e4682d04fc2c X-Git-Newrev: 1e1b247774e0239f73b59e07f30db4e400f9b4eb Message-Id: <20220421125204.14E7E380DBE9@sourceware.org> Date: Thu, 21 Apr 2022 12:52:04 +0000 (GMT) X-BeenThere: gcc-cvs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 21 Apr 2022 12:52:04 -0000 https://gcc.gnu.org/g:1e1b247774e0239f73b59e07f30db4e400f9b4eb commit r10-10549-g1e1b247774e0239f73b59e07f30db4e400f9b4eb Author: Richard Biener Date: Thu Jan 20 14:25:51 2022 +0100 middle-end/100786 - constant folding from incompatible alias The following avoids us ICEing doing constant folding from variables with aliases of different types. The issue appears both in folding and CCP and FRE can do more fancy stuff to still constant fold cases where the load is smaller than the initializer so defer it to there. 2022-01-20 Richard Biener PR middle-end/100786 * gimple-fold.c (get_symbol_constant_value): Only return values of compatible type to the symbol. * gcc.dg/torture/pr100786.c: New testcase. (cherry picked from commit 5c12507f5d0bc080e4f346af99824e039236e61c) Diff: --- gcc/gimple-fold.c | 4 +++- gcc/testsuite/gcc.dg/torture/pr100786.c | 9 +++++++++ 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 912540dc8a7..969c3998421 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -285,7 +285,9 @@ get_symbol_constant_value (tree sym) if (val) { val = canonicalize_constructor_val (unshare_expr (val), sym); - if (val && is_gimple_min_invariant (val)) + if (val + && is_gimple_min_invariant (val) + && useless_type_conversion_p (TREE_TYPE (sym), TREE_TYPE (val))) return val; else return NULL_TREE; diff --git a/gcc/testsuite/gcc.dg/torture/pr100786.c b/gcc/testsuite/gcc.dg/torture/pr100786.c new file mode 100644 index 00000000000..42f4e485593 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr100786.c @@ -0,0 +1,9 @@ +/* { dg-do compile } */ + +const double a = 0; +extern int b __attribute__((alias("a"))); +void inc() { b++; } + +const int a2 = 0; +extern double b2 __attribute__((alias("a2"))); +void inc2() { b2+=1; }