From: Jakub Jelinek <jakub@redhat.com>
Date: Thu, 11 Feb 2016 09:04:19 +0000 (+0100)
Subject: backport: re PR target/67770 (i386: -fshrink-wrap can interact badly with trampolines)
X-Git-Tag: releases/gcc-4.9.4~345
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5710d371f54c1db23ae7ae80ba9974beea188e55;p=thirdparty%2Fgcc.git

backport: re PR target/67770 (i386: -fshrink-wrap can interact badly with trampolines)

	Backported from mainline
	2015-11-19  Jakub Jelinek  <jakub@redhat.com>

	PR target/67770
	* config/i386/i386.md (simple_return): Disable if
	ix86_static_chain_on_stack is true.

	* gcc.target/i386/pr67770.c: New test.

From-SVN: r233319
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f5e18855d473..f63667bcde57 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,12 @@
+2016-02-11  Jakub Jelinek  <jakub@redhat.com>
+
+	Backported from mainline
+	2015-11-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/67770
+	* config/i386/i386.md (simple_return): Disable if
+	ix86_static_chain_on_stack is true.
+
 2016-02-04  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 2b19f6e307ec..bf148ed5cd2b 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -11584,10 +11584,14 @@
 ;; We need to disable this for TARGET_SEH, as otherwise
 ;; shrink-wrapped prologue gets enabled too.  This might exceed
 ;; the maximum size of prologue in unwind information.
+;; Also disallow shrink-wrapping if using stack slot to pass the
+;; static chain pointer - the first instruction has to be pushl %esi
+;; and it can't be moved around, as we use alternate entry points
+;; in that case.
 
 (define_expand "simple_return"
   [(simple_return)]
-  "!TARGET_SEH"
+  "!TARGET_SEH && !ix86_static_chain_on_stack"
 {
   if (crtl->args.pops_args)
     {
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0e077ca069d5..48a77ec19315 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,11 @@
+2016-02-11  Jakub Jelinek  <jakub@redhat.com>
+
+	Backported from mainline
+	2015-11-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR target/67770
+	* gcc.target/i386/pr67770.c: New test.
+
 2016-02-04  Jakub Jelinek  <jakub@redhat.com>
 
 	Backported from mainline
diff --git a/gcc/testsuite/gcc.target/i386/pr67770.c b/gcc/testsuite/gcc.target/i386/pr67770.c
new file mode 100644
index 000000000000..3826aff45b74
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr67770.c
@@ -0,0 +1,40 @@
+/* PR target/67770 */
+/* { dg-do run { target ia32 } } */
+/* { dg-require-effective-target trampolines } */
+/* { dg-options "-O2" } */
+
+#ifndef NO_TRAMPOLINES
+__attribute__ ((noinline)) void
+foo (int i, void (* __attribute__ ((regparm (3))) bar) (int))
+{
+  bar (i);
+}
+#endif
+
+int
+main ()
+{
+#ifndef NO_TRAMPOLINES
+  int p = 0;
+
+  __attribute__ ((regparm (3), noinline)) void
+  bar (int i)
+  {
+    if (__builtin_expect (i, 0))
+      ++p;
+  }
+
+  foo (0, bar);
+  bar (0);
+
+  if (p != 0)
+    __builtin_abort ();
+
+  foo (1, bar);
+  bar (1);
+
+  if (p != 2)
+    __builtin_abort ();
+#endif
+  return 0;
+}