re PR middle-end/54921 (wrong code with -Os -fno-omit-frame-pointer -fsched2-use-superblocks -fstack-protector -ftree-slp-vectorize)

	PR rtl-optimization/54921
	* cselib.h (fp_setter_insn): New prototype.
	* cselib.c (fp_setter_insn): New function.
	(cselib_process_insn): If frame_pointer_needed,
	call cselib_invalidate_rtx (stack_pointer_rtx) after
	processing a frame pointer setter.
	* var-tracking.c (fp_setter): Removed.
	(vt_initialize): Use fp_setter_insn instead of fp_setter.

	* gcc.dg/pr54921.c: New test.

From-SVN: r193647

6 files changed, 80 insertions, 36 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 27bcf01..d3b0200 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2012-11-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/54921
+	* cselib.h (fp_setter_insn): New prototype.
+	* cselib.c (fp_setter_insn): New function.
+	(cselib_process_insn): If frame_pointer_needed,
+	call cselib_invalidate_rtx (stack_pointer_rtx) after
+	processing a frame pointer setter.
+	* var-tracking.c (fp_setter): Removed.
+	(vt_initialize): Use fp_setter_insn instead of fp_setter.
+
 2012-11-19  Michael Meissner  <meissner@linux.vnet.ibm.com>
 
 	* config/rs6000/rs6000.md (movdf_hardfloat32): Reorder move
diff --git a/gcc/cselib.c b/gcc/cselib.c
index 92193ba..28f8d07 100644
--- a/gcc/cselib.c
+++ b/gcc/cselib.c
@@ -2593,6 +2593,28 @@ cselib_record_sets (rtx insn)
     }
 }
 
+/* Return true if INSN in the prologue initializes hard_frame_pointer_rtx.  */
+
+bool
+fp_setter_insn (rtx insn)
+{
+  rtx expr, pat = NULL_RTX;
+
+  if (!RTX_FRAME_RELATED_P (insn))
+    return false;
+
+  expr = find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX);
+  if (expr)
+    pat = XEXP (expr, 0);
+  if (!modified_in_p (hard_frame_pointer_rtx, pat ? pat : insn))
+    return false;
+
+  /* Don't return true for frame pointer restores in the epilogue.  */
+  if (find_reg_note (insn, REG_CFA_RESTORE, hard_frame_pointer_rtx))
+    return false;
+  return true;
+}
+
 /* Record the effects of INSN.  */
 
 void
@@ -2651,6 +2673,14 @@ cselib_process_insn (rtx insn)
       if (GET_CODE (XEXP (x, 0)) == CLOBBER)
 	cselib_invalidate_rtx (XEXP (XEXP (x, 0), 0));
 
+  /* On setter of the hard frame pointer if frame_pointer_needed,
+     invalidate stack_pointer_rtx, so that sp and {,h}fp based
+     VALUEs are distinct.  */
+  if (reload_completed
+      && frame_pointer_needed
+      && fp_setter_insn (insn))
+    cselib_invalidate_rtx (stack_pointer_rtx);
+
   cselib_current_insn = NULL_RTX;
 
   if (n_useless_values > MAX_USELESS_VALUES
diff --git a/gcc/cselib.h b/gcc/cselib.h
index 95fdbf7..b717c95 100644
--- a/gcc/cselib.h
+++ b/gcc/cselib.h
@@ -78,6 +78,7 @@ extern void cselib_init (int);
 extern void cselib_clear_table (void);
 extern void cselib_finish (void);
 extern void cselib_process_insn (rtx);
+extern bool fp_setter_insn (rtx);
 extern enum machine_mode cselib_reg_set_mode (const_rtx);
 extern int rtx_equal_for_cselib_p (rtx, rtx);
 extern int references_value_p (const_rtx, int);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 5148099..46eb0cd 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2012-11-20  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/54921
+	* gcc.dg/pr54921.c: New test.
+
 2012-11-19  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	* gcc.target/i386/pr55359.c: New test.
diff --git a/gcc/testsuite/gcc.dg/pr54921.c b/gcc/testsuite/gcc.dg/pr54921.c
new file mode 100644
index 0000000..897877a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr54921.c
@@ -0,0 +1,32 @@
+/* PR rtl-optimization/54921 */
+/* { dg-do run } */
+/* { dg-options "-Os -fno-omit-frame-pointer -fsched2-use-superblocks -ftree-slp-vectorize" } */
+/* { dg-additional-options "-fstack-protector" { target fstack_protector } } */
+
+struct A
+{
+  int a;
+  char b[32];
+} a, b;
+
+__attribute__((noinline, noclone))
+struct A
+bar (int x)
+{
+  struct A r;
+  static int n;
+  r.a = ++n;
+  __builtin_memset (r.b, 0, sizeof (r.b));
+  r.b[0] = x;
+  return r;
+}
+
+int
+main ()
+{
+  a = bar (3);
+  b = bar (4);
+  if (a.a != 1 || a.b[0] != 3 || b.a != 2 || b.b[0] != 4)
+    __builtin_abort ();
+  return 0;
+}
diff --git a/gcc/var-tracking.c b/gcc/var-tracking.c
index e95cf87..f5ba115 100644
--- a/gcc/var-tracking.c
+++ b/gcc/var-tracking.c
@@ -9522,40 +9522,6 @@ vt_add_function_parameters (void)
     }
 }
 
-/* Return true if INSN in the prologue initializes hard_frame_pointer_rtx.  */
-
-static bool
-fp_setter (rtx insn)
-{
-  rtx pat = PATTERN (insn);
-  if (RTX_FRAME_RELATED_P (insn))
-    {
-      rtx expr = find_reg_note (insn, REG_FRAME_RELATED_EXPR, NULL_RTX);
-      if (expr)
-	pat = XEXP (expr, 0);
-    }
-  if (GET_CODE (pat) == SET)
-    {
-      if (SET_DEST (pat) != hard_frame_pointer_rtx)
-	return false;
-    }
-  else if (GET_CODE (pat) == PARALLEL)
-    {
-      int i;
-      for (i = XVECLEN (pat, 0) - 1; i >= 0; i--)
-	if (GET_CODE (XVECEXP (pat, 0, i)) == SET
-	    && SET_DEST (XVECEXP (pat, 0, i)) == hard_frame_pointer_rtx)
-	  break;
-      if (i < 0)
-	return false;
-    }
-  else
-    return false;
-  if (find_reg_note (insn, REG_CFA_RESTORE, hard_frame_pointer_rtx))
-    return false;
-  return true;
-}
-
 /* Initialize cfa_base_rtx, create a preserved VALUE for it and
    ensure it isn't flushed during cselib_reset_table.
    Can be called only if frame_pointer_rtx resp. arg_pointer_rtx
@@ -9859,8 +9825,7 @@ vt_initialize (void)
 
 		  if (fp_cfa_offset != -1
 		      && hard_frame_pointer_adjustment == -1
-		      && RTX_FRAME_RELATED_P (insn)
-		      && fp_setter (insn))
+		      && fp_setter_insn (insn))
 		    {
 		      vt_init_cfa_base ();
 		      hard_frame_pointer_adjustment = fp_cfa_offset;