This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [PATCH, PR 63551] Use proper type in evaluate_conditions_for_known_args
- From: Martin Jambor <mjambor at suse dot cz>
- To: Richard Biener <richard dot guenther at gmail dot com>
- Cc: GCC Patches <gcc-patches at gcc dot gnu dot org>, Jan Hubicka <hubicka at ucw dot cz>
- Date: Sat, 22 Nov 2014 12:09:46 +0100
- Subject: Re: [PATCH, PR 63551] Use proper type in evaluate_conditions_for_known_args
- Authentication-results: sourceware.org; auth=none
- References: <20141121200750 dot GD7784 at virgil dot suse> <FD5F63F7-0D0B-47AB-BA13-9838302C7F20 at gmail dot com>
Hi,
On Fri, Nov 21, 2014 at 09:18:03PM +0100, Richard Biener wrote:
> On November 21, 2014 9:07:50 PM CET, Martin Jambor <mjambor@suse.cz> wrote:
> >the testcase of PR 63551 passes a union between a signed and an
> >unsigned integer between two functions as a parameter. The caller
> >initializes to an unsigned integer with the highest order bit set, the
> >callee loads the data through the signed field and compares with zero.
> >evaluate_conditions_for_known_args then wrongly evaluated the
> >condition in these circumstances, which later on lead to insertion of
> >builtin_unreachable and miscompilation.
> >
> >Fixed by fold_converting the known value first. I use the type of the
> >value in the condition which should do exactly the right thing because
> >the value is taken from the corresponding gimple_cond statement in
> >which types must match.
> >
> >Bootstrapped and tested on x86_64-linux. OK for trunk?
>
> I think you want to use fold_unary (VIEW_CONVERT,...) Here if you consider the case with
> Int and float. And "fail" if that returns NULL or not a constant.
>
You are of course right. The following does exactly that.
Bootstrapped and tested on x86_64-linux on trunk and the 4.9 branch.
OK for both?
Thanks,
Martin
2014-11-21 Martin Jambor <mjambor@suse.cz>
PR ipa/63551
* ipa-inline-analysis.c (evaluate_conditions_for_known_args): Convert
value of the argument to the type of the value in the condition.
testsuite/
* gcc.dg/ipa/pr63551.c: New test.
Index: src/gcc/ipa-inline-analysis.c
===================================================================
--- src.orig/gcc/ipa-inline-analysis.c
+++ src/gcc/ipa-inline-analysis.c
@@ -880,7 +880,10 @@ evaluate_conditions_for_known_args (stru
}
if (c->code == IS_NOT_CONSTANT || c->code == CHANGED)
continue;
- res = fold_binary_to_constant (c->code, boolean_type_node, val, c->val);
+ val = fold_unary (VIEW_CONVERT_EXPR, TREE_TYPE (c->val), val);
+ res = val
+ ? fold_binary_to_constant (c->code, boolean_type_node, val, c->val)
+ : NULL;
if (res && integer_zerop (res))
continue;
clause |= 1 << (i + predicate_first_dynamic_condition);
Index: src/gcc/testsuite/gcc.dg/ipa/pr63551.c
===================================================================
--- /dev/null
+++ src/gcc/testsuite/gcc.dg/ipa/pr63551.c
@@ -0,0 +1,33 @@
+/* { dg-do run } */
+/* { dg-options "-Os" } */
+
+union U
+{
+ unsigned int f0;
+ int f1;
+};
+
+int a, d;
+
+void
+fn1 (union U p)
+{
+ if (p.f1 <= 0)
+ if (a)
+ d = 0;
+}
+
+void
+fn2 ()
+{
+ d = 0;
+ union U b = { 4294967286 };
+ fn1 (b);
+}
+
+int
+main ()
+{
+ fn2 ();
+ return 0;
+}