From 56f9cf9142a6f54fd692c409d0faed607e2cb873 Mon Sep 17 00:00:00 2001
From: Eric Botcazou <ebotcazou@adacore.com>
Date: Fri, 21 Sep 2018 10:06:25 +0000
Subject: [PATCH] rs6000.c (rs6000_function_ok_for_sibcall): Return false if
 the call takes a static chain.

	* config/rs6000/rs6000.c (rs6000_function_ok_for_sibcall): Return false
	if the call takes a static chain.

From-SVN: r264465
---
 gcc/ChangeLog                         |  5 ++++
 gcc/config/rs6000/rs6000.c            |  6 +++++
 gcc/testsuite/ChangeLog               |  4 ++++
 gcc/testsuite/gcc.dg/nested-func-11.c | 34 +++++++++++++++++++++++++++
 4 files changed, 49 insertions(+)
 create mode 100644 gcc/testsuite/gcc.dg/nested-func-11.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a076b8816189..471a203d2958 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2018-09-21  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* config/rs6000/rs6000.c (rs6000_function_ok_for_sibcall): Return false
+	if the call takes a static chain.
+
 2018-09-19  John David Anglin  <danglin@gcc.gnu.org>
 
 	* config/pa/pa.md (atomic_storeqi): Restore deleted expander.
diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c
index 365f006af626..d377e2429135 100644
--- a/gcc/config/rs6000/rs6000.c
+++ b/gcc/config/rs6000/rs6000.c
@@ -27793,6 +27793,12 @@ rs6000_function_ok_for_sibcall (tree decl, tree exp)
 {
   tree fntype;
 
+  /* The sibcall epilogue may clobber the static chain register.
+     ??? We could work harder and avoid that, but it's probably
+     not worth the hassle in practice.  */
+  if (CALL_EXPR_STATIC_CHAIN (exp))
+    return false;
+
   if (decl)
     fntype = TREE_TYPE (decl);
   else
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 60ce73f3a3dc..55bf1c25c9c8 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2018-09-21  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc.dg/nested-func-11.c: New test.
+
 2018-09-13  Paul Thomas  <pault@gcc.gnu.org>
 
 	Backported from trunk
diff --git a/gcc/testsuite/gcc.dg/nested-func-11.c b/gcc/testsuite/gcc.dg/nested-func-11.c
new file mode 100644
index 000000000000..01096b4147f6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/nested-func-11.c
@@ -0,0 +1,34 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -fno-omit-frame-pointer" } */
+
+int __attribute__((noipa)) foo (int i)
+{
+  int a;
+
+  void __attribute__((noipa)) nested2 (int i)
+  {
+    a = i;
+  }
+
+  void  __attribute__((noipa)) nested1 (int i)
+  {
+    int b[32];
+
+    for (int j = 0; j < 32; j++)
+      b[j] = i + j;
+
+    nested2 (b[i]);
+  }
+
+  nested1 (i);
+
+  return a;
+}
+
+int main (void)
+{
+  if (foo (4) != 8)
+    __builtin_abort ();
+
+  return 0;
+}
-- 
2.47.2