Replicate static chain on the stack

If we put static chain on the stack, we need to replicate it on the stack
when stack is realigned with DRAP so that static chain can be reached via
(argp - 2) slot.

gcc/

	PR target/66906
	* config/i386/i386.c (ix86_expand_prologue): Replicate static
	chain on the stack.

gcc/testsuite/

	PR target/66906
	* gcc.target/i386/pr66906.c: New test.

From-SVN: r225974

4 files changed, 68 insertions, 1 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index fc24180..6d58319 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2015-07-17  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/66906
+	* config/i386/i386.c (ix86_expand_prologue): Replicate static
+	chain on the stack.
+
 2015-07-17  Nathan Sidwell  <nathan@codesourcery.com>
 
 	* config/nvptx/mkoffload.c (process): Constify host data.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 55e1e2d..01a1cb9 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -11495,6 +11495,7 @@ ix86_expand_prologue (void)
   HOST_WIDE_INT allocate;
   bool int_registers_saved;
   bool sse_registers_saved;
+  rtx static_chain = NULL_RTX;
 
   ix86_finalize_stack_realign_flags ();
 
@@ -11593,7 +11594,8 @@ ix86_expand_prologue (void)
      call.  This insn will be skipped by the trampoline.  */
   else if (ix86_static_chain_on_stack)
     {
-      insn = emit_insn (gen_push (ix86_static_chain (cfun->decl, false)));
+      static_chain = ix86_static_chain (cfun->decl, false);
+      insn = emit_insn (gen_push (static_chain));
       emit_insn (gen_blockage ());
 
       /* We don't want to interpret this push insn as a register save,
@@ -11645,6 +11647,15 @@ ix86_expand_prologue (void)
 	 we've started over with a new frame.  */
       m->fs.sp_offset = INCOMING_FRAME_SP_OFFSET;
       m->fs.realigned = true;
+
+      if (static_chain)
+	{
+	  /* Replicate static chain on the stack so that static chain
+	     can be reached via (argp - 2) slot.  This is needed for
+	     nested function with stack realignment.  */
+	  insn = emit_insn (gen_push (static_chain));
+	  RTX_FRAME_RELATED_P (insn) = 1;
+	}
     }
 
   int_registers_saved = (frame.nregs == 0);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index a27f032..9628a20 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-07-17  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/66906
+	* gcc.target/i386/pr66906.c: New test.
+
 2015-07-17  Mikael Morin  <mikael@gcc.gnu.org>
 
 	* gfortran.dg/coarray_collectives_16.f90: Fix pattern
diff --git a/gcc/testsuite/gcc.target/i386/pr66906.c b/gcc/testsuite/gcc.target/i386/pr66906.c
new file mode 100644
index 0000000..969e183
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr66906.c
@@ -0,0 +1,45 @@
+/* { dg-do run { target ia32 } } */
+/* { dg-options "-O0 -mregparm=3" } */
+
+typedef int ptrdiff_t;
+extern void abort (void);
+int
+check_int (int *i, int align)
+{
+  *i = 20;
+  if ((((ptrdiff_t) i) & (align - 1)) != 0)
+    abort ();
+  return *i;
+}
+void
+check (void *p, int align)
+{
+  if ((((ptrdiff_t) p) & (align - 1)) != 0)
+    abort ();
+}
+typedef int aligned __attribute__((aligned(64)));
+void
+foo (void)
+{
+  aligned j;
+  void bar ()
+    {
+      aligned i;
+      if (check_int (&i, __alignof__(i)) != i)
+	abort ();
+      if (check_int (&j, __alignof__(j)) != j)
+	abort ();
+      j = -20;
+    }
+  bar ();
+  if (j != -20)
+    abort ();
+  if (check_int (&j, __alignof__(j)) != j)
+    abort ();
+}
+int
+main()
+{
+  foo ();
+  return 0;
+}