patch to fix PR81572

[Vladimir Makarov <vmakarov at redhat dot com>]

  The following patch fixes

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81572

  The patch was successfully bootstrapped and tested on ppc64.

  Committed as rev. 257915.

Index: ChangeLog
===================================================================
--- ChangeLog	(revision 257901)
+++ ChangeLog	(working copy)
@@ -1,3 +1,19 @@
+2018-02-22  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/81572
+	* lra-int.h (LRA_UNKNOWN_ALT, LRA_NON_CLOBBERED_ALT): New macros.
+	* lra.c (lra_set_insn_recog_data, lra_update_insn_recog_data): Use
+	LRA_UNKNOWN_ALT.
+	* lra-constraints.c (curr_insn_transform): Set up
+	LRA_NON_CLOBBERED_ALT for moves processed on the fast path.  Use
+	LRA_UNKNOWN_ALT.
+	(remove_inheritance_pseudos): Use LRA_UNKNOWN_ALT.
+	* lra-eliminations.c (spill_pseudos): Ditto.
+	(process_insn_for_elimination): Ditto.
+	* lra-lives.c (reg_early_clobber_p): Use the new macros.
+	* lra-spills.c (spill_pseudos): Use LRA_UNKNOWN_ALT and
+	LRA_NON_CLOBBERED_ALT.
+
 2018-02-22  Martin Liska  <mliska@suse.cz>
 
 	PR driver/83193
Index: lra-constraints.c
===================================================================
--- lra-constraints.c	(revision 257901)
+++ lra-constraints.c	(working copy)
@@ -3730,7 +3730,13 @@ curr_insn_transform (bool check_only_p)
 
   curr_insn_set = single_set (curr_insn);
   if (curr_insn_set != NULL_RTX && simple_move_p ())
-    return false;
+    {
+      /* We assume that the corresponding insn alternative has no
+	 earlier clobbers.  If it is not the case, don't define move
+	 cost equal to 2 for the corresponding register classes.  */
+      lra_set_used_insn_alternative (curr_insn, LRA_NON_CLOBBERED_ALT);
+      return false;
+    }
 
   no_input_reloads_p = no_output_reloads_p = false;
   goal_alt_number = -1;
@@ -3838,7 +3844,7 @@ curr_insn_transform (bool check_only_p)
   if (change_p)
     /* If we've changed the instruction then any alternative that
        we chose previously may no longer be valid.  */
-    lra_set_used_insn_alternative (curr_insn, -1);
+    lra_set_used_insn_alternative (curr_insn, LRA_UNKNOWN_ALT);
 
   if (! check_only_p && curr_insn_set != NULL_RTX
       && check_and_process_move (&change_p, &sec_mem_p))
@@ -3846,7 +3852,7 @@ curr_insn_transform (bool check_only_p)
 
  try_swapped:
 
-  reused_alternative_num = check_only_p ? -1 : curr_id->used_insn_alternative;
+  reused_alternative_num = check_only_p ? LRA_UNKNOWN_ALT : curr_id->used_insn_alternative;
   if (lra_dump_file != NULL && reused_alternative_num >= 0)
     fprintf (lra_dump_file, "Reusing alternative %d for insn #%u\n",
 	     reused_alternative_num, INSN_UID (curr_insn));
@@ -6752,7 +6758,7 @@ remove_inheritance_pseudos (bitmap remov
 			}
 		      lra_push_insn_and_update_insn_regno_info (curr_insn);
 		      lra_set_used_insn_alternative_by_uid
-			(INSN_UID (curr_insn), -1);
+			(INSN_UID (curr_insn), LRA_UNKNOWN_ALT);
 		      done_p = true;
 		      if (lra_dump_file != NULL)
 			{
@@ -6791,7 +6797,7 @@ remove_inheritance_pseudos (bitmap remov
 		     constraints pass.  */
 		  lra_push_insn_and_update_insn_regno_info (curr_insn);
 		  lra_set_used_insn_alternative_by_uid
-		    (INSN_UID (curr_insn), -1);
+		    (INSN_UID (curr_insn), LRA_UNKNOWN_ALT);
 		}
 	      else if (restored_regs_p)
 		/* The instruction has been restored to the form that
Index: lra-eliminations.c
===================================================================
--- lra-eliminations.c	(revision 257901)
+++ lra-eliminations.c	(working copy)
@@ -1175,7 +1175,7 @@ spill_pseudos (HARD_REG_SET set)
     if (bitmap_bit_p (&to_process, INSN_UID (insn)))
       {
 	lra_push_insn (insn);
-	lra_set_used_insn_alternative (insn, -1);
+	lra_set_used_insn_alternative (insn, LRA_UNKNOWN_ALT);
       }
   bitmap_clear (&to_process);
 }
@@ -1408,7 +1408,7 @@ process_insn_for_elimination (rtx_insn *
 	}
       lra_update_insn_regno_info (insn);
       lra_push_insn (insn);
-      lra_set_used_insn_alternative (insn, -1);
+      lra_set_used_insn_alternative (insn, LRA_UNKNOWN_ALT);
     }
 }
 
Index: lra-int.h
===================================================================
--- lra-int.h	(revision 257901)
+++ lra-int.h	(working copy)
@@ -202,15 +202,20 @@ struct lra_static_insn_data
   const struct operand_alternative *operand_alternative;
 };
 
+/* Negative insn alternative numbers used for special cases.  */
+#define LRA_UNKNOWN_ALT -1
+#define LRA_NON_CLOBBERED_ALT -2
+
 /* LRA internal info about an insn (LRA internal insn
    representation).  */
 struct lra_insn_recog_data
 {
   /* The insn code.  */
   int icode;
-  /* The alternative should be used for the insn, -1 if invalid, or we
-     should try to use any alternative, or the insn is a debug
-     insn.  */
+  /* The alternative should be used for the insn, LRA_UNKNOWN_ALT if
+     unknown, or we should assume any alternative, or the insn is a
+     debug insn.  LRA_NON_CLOBBERED_ALT means ignoring any earlier
+     clobbers for the insn.  */
   int used_insn_alternative;
   /* SP offset before the insn relative to one at the func start.  */
   poly_int64 sp_offset;
Index: lra-lives.c
===================================================================
--- lra-lives.c	(revision 257901)
+++ lra-lives.c	(working copy)
@@ -598,7 +598,9 @@ static inline bool
 reg_early_clobber_p (const struct lra_insn_reg *reg, int n_alt)
 {
   return (reg->early_clobber
-	  && (n_alt < 0 || TEST_BIT (reg->early_clobber_alts, n_alt)));
+	  && (n_alt == LRA_UNKNOWN_ALT
+	      || (n_alt != LRA_NON_CLOBBERED_ALT
+		  && TEST_BIT (reg->early_clobber_alts, n_alt))));
 }
 
 /* Process insns of the basic block BB to update pseudo live ranges,
Index: lra-spills.c
===================================================================
--- lra-spills.c	(revision 257901)
+++ lra-spills.c	(working copy)
@@ -517,7 +517,7 @@ spill_pseudos (void)
 			 INSN_UID (insn));
 	      lra_push_insn (insn);
 	      if (lra_reg_spill_p || targetm.different_addr_displacement_p ())
-		lra_set_used_insn_alternative (insn, -1);
+		lra_set_used_insn_alternative (insn, LRA_UNKNOWN_ALT);
 	    }
 	  else if (CALL_P (insn)
 		   /* Presence of any pseudo in CALL_INSN_FUNCTION_USAGE
Index: lra.c
===================================================================
--- lra.c	(revision 257901)
+++ lra.c	(working copy)
@@ -958,7 +958,7 @@ lra_set_insn_recog_data (rtx_insn *insn)
   data = XNEW (struct lra_insn_recog_data);
   lra_insn_recog_data[uid] = data;
   data->insn = insn;
-  data->used_insn_alternative = -1;
+  data->used_insn_alternative = LRA_UNKNOWN_ALT;
   data->icode = icode;
   data->regs = NULL;
   if (DEBUG_INSN_P (insn))
@@ -1207,7 +1207,7 @@ lra_update_insn_recog_data (rtx_insn *in
       return data;
     }
   insn_static_data = data->insn_static_data;
-  data->used_insn_alternative = -1;
+  data->used_insn_alternative = LRA_UNKNOWN_ALT;
   if (DEBUG_INSN_P (insn))
     return data;
   if (data->icode < 0)
Index: testsuite/ChangeLog
===================================================================
--- testsuite/ChangeLog	(revision 257901)
+++ testsuite/ChangeLog	(working copy)
@@ -1,3 +1,8 @@
+2018-02-22  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/81572
+	* gcc.target/powerpc/pr81572.c: New.
+
 2018-02-22  Marek Polacek  <polacek@redhat.com>
 
 	PR c++/84493
Index: testsuite/gcc.target/powerpc/pr81572.c
===================================================================
--- testsuite/gcc.target/powerpc/pr81572.c	(revision 0)
+++ testsuite/gcc.target/powerpc/pr81572.c	(working copy)
@@ -0,0 +1,13 @@
+/* { dg-do compile { target powerpc64*-*-* } } */
+/* { dg-options "-O2 -mcpu=power7" } */
+/* { dg-final { scan-assembler-not "xxlor" } } */
+
+#include <altivec.h>
+
+typedef __vector unsigned char nvec_t;
+
+long testz_and(nvec_t a, nvec_t b)
+{
+  nvec_t c = vec_andc(a, b);
+  return vec_all_eq(a, c);
+}