From: Martin Jambor <mjambor@suse.cz>
Date: Mon, 3 Apr 2023 13:53:36 +0000 (+0200)
Subject: ipa: Avoid constructing aggregate jump functions with huge offsets (PR 109303)
X-Git-Tag: basepoints/gcc-14~221
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=da3fd01757297c1d20cf3dcd76046488da737569;p=thirdparty%2Fgcc.git

ipa: Avoid constructing aggregate jump functions with huge offsets (PR 109303)

We are in the process of changing data structures holding information
about constants passed by reference and in aggregates to use unsigned
int offsets rather than HOST_WIDE_INT (which was selected simply
because that is what fell out of get_ref_base_and_extent at that time)
in order to conserve memory, especially at WPA time.

PR 109303 testcase discovers that we do not properly check that we
only create jump functions with offsets (plus sizes) that fit into the
smaller type.  This patch adds the necessary check.

gcc/ChangeLog:

2023-03-30  Martin Jambor  <mjambor@suse.cz>

	PR ipa/109303
	* ipa-prop.cc (determine_known_aggregate_parts): Check that the
	offset + size will be representable in unsigned int.

gcc/testsuite/ChangeLog:

2023-03-30  Jakub Jelinek  <jakub@redhat.com>
	    Martin Jambor  <mjambor@suse.cz>

	PR ipa/109303
	* gcc.dg/pr109303.c: New test.
---

diff --git a/gcc/ipa-prop.cc b/gcc/ipa-prop.cc
index de45dbccf16d..83a181672738 100644
--- a/gcc/ipa-prop.cc
+++ b/gcc/ipa-prop.cc
@@ -2086,7 +2086,12 @@ determine_known_aggregate_parts (struct ipa_func_body_info *fbi,
 	     whether its value is clobbered any other dominating one.  */
 	  if ((content->value.pass_through.formal_id >= 0
 	       || content->value.pass_through.operand)
-	      && !clobber_by_agg_contents_list_p (all_list, content))
+	      && !clobber_by_agg_contents_list_p (all_list, content)
+	      /* Since IPA-CP stores results with unsigned int offsets, we can
+		 discard those which would not fit now before we stream them to
+		 WPA.  */
+	      && (content->offset + content->size - arg_offset
+		  <= (HOST_WIDE_INT) UINT_MAX * BITS_PER_UNIT))
 	    {
 	      struct ipa_known_agg_contents_list *copy
 			= XALLOCA (struct ipa_known_agg_contents_list);
diff --git a/gcc/testsuite/gcc.dg/pr109303.c b/gcc/testsuite/gcc.dg/pr109303.c
new file mode 100644
index 000000000000..f91535991c78
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr109303.c
@@ -0,0 +1,24 @@
+/* PR ipa/109303 */
+/* { dg-do compile { target lp64 } } */
+/* { dg-options "-O2" } */
+
+struct __attribute__((packed)) A { char c1; short a1[__INT_MAX__]; };
+struct __attribute__((packed)) B { char c2; short a2[100]; };
+struct S { struct A p1; struct B p2[4]; };
+void bar (short int);
+
+static void
+foo (struct S *q)
+{
+  for (int i = 0; i < q->p1.c1; i++)
+    for (int j = 0; j < q->p2[i].c2; j++)
+      bar (q->p2[i].a2[j]);
+}
+
+int
+main ()
+{
+  struct S q = {};
+  q.p2[0].c2 = q.p2[1].c2 = 3;
+  foo (&q);
+}