re PR rtl-optimization/92796 (ICE in lra_assign, at lra-assigns.c:1646 on powerpc64le-linux-gnu)

2019-12-10  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/92796
	* lra-int.h (lra_risky_transformations_p): Rename to
	check_and_force_assignment_correctness_p.
	* lra-assigns.c: Ditto.
	(lra_assign): Reset check_and_force_assignment_correctness_p.
	* lra-constraints.c (lra_risky_transformations_p): Rename to
	check_and_force_assignment_correctness_p.
	(lra_constraints): Set up check_and_force_assignment_correctness_p
	only for the 1st sub-pass.
	* lra-eliminations.c (process_insn_for_elimination): Set up
	check_and_force_assignment_correctness_p if the insn chnaged its
	code.

2019-12-10  Vladimir Makarov  <vmakarov@redhat.com>

	PR rtl-optimization/92796
	* gcc.target/powerpc/pr92796.c: New test.

From-SVN: r279204

1 files changed, 15 insertions, 12 deletions

diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index 39d2d2c..9e0f50e 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -4665,11 +4665,14 @@ loc_equivalence_callback (rtx loc, const_rtx, void *data)
 /* The current iteration number of this LRA pass.  */
 int lra_constraint_iter;
 
-/* True if we substituted equiv which needs checking register
-   allocation correctness because the equivalent value contains
-   allocatable hard registers or when we restore multi-register
-   pseudo.  */
-bool lra_risky_transformations_p;
+/* True if we should during assignment sub-pass check assignment
+   correctness for all pseudos and spill some of them to correct
+   conflicts.  It can be necessary when we substitute equiv which
+   needs checking register allocation correctness because the
+   equivalent value contains allocatable hard registers, or when we
+   restore multi-register pseudo, or when we change the insn code and
+   its operand became INOUT operand when it was IN one before.  */
+bool check_and_force_assignment_correctness_p;
 
 /* Return true if REGNO is referenced in more than one block.  */
 static bool
@@ -4811,14 +4814,14 @@ lra_constraints (bool first_p)
   changed_p = false;
   if (pic_offset_table_rtx
       && REGNO (pic_offset_table_rtx) >= FIRST_PSEUDO_REGISTER)
-    lra_risky_transformations_p = true;
-  else
+    check_and_force_assignment_correctness_p = true;
+  else if (first_p)
     /* On the first iteration we should check IRA assignment
        correctness.  In rare cases, the assignments can be wrong as
        early clobbers operands are ignored in IRA or usages of
        paradoxical sub-registers are not taken into account by
        IRA.  */
-    lra_risky_transformations_p = first_p;
+    check_and_force_assignment_correctness_p = true;
   new_insn_uid_start = get_max_uid ();
   new_regno_start = first_p ? lra_constraint_new_regno_start : max_reg_num ();
   /* Mark used hard regs for target stack size calulations.  */
@@ -4994,7 +4997,7 @@ lra_constraints (bool first_p)
 		      dump_insn_slim (lra_dump_file, curr_insn);
 		    }
 		  if (contains_reg_p (x, true, false))
-		    lra_risky_transformations_p = true;
+		    check_and_force_assignment_correctness_p = true;
 		  lra_set_insn_deleted (curr_insn);
 		  continue;
 		}
@@ -5507,7 +5510,7 @@ need_for_split_p (HARD_REG_SET potential_reload_hard_regs, int regno)
 	   /* Don't split call clobbered hard regs living through
 	      calls, otherwise we might have a check problem in the
 	      assign sub-pass as in the most cases (exception is a
-	      situation when lra_risky_transformations_p value is
+	      situation when check_and_force_assignment_correctness_p value is
 	      true) the assign pass assumes that all pseudos living
 	      through calls are assigned to call saved hard regs.  */
 	   && (regno >= FIRST_PSEUDO_REGISTER
@@ -5799,7 +5802,7 @@ split_reg (bool before_p, int original_regno, rtx_insn *insn,
        sub-register levels, LRA do this on pseudos level right now and
        this discrepancy may create allocation conflicts after
        splitting.  */
-    lra_risky_transformations_p = true;
+    check_and_force_assignment_correctness_p = true;
   if (lra_dump_file != NULL)
     fprintf (lra_dump_file,
 	     "	  ))))))))))))))))))))))))))))))))))))))))))))))))\n");
@@ -6561,7 +6564,7 @@ inherit_in_ebb (rtx_insn *head, rtx_insn *tail)
 						 before_p, curr_insn, max_uid))
 			{
 			  if (reg->subreg_p)
-			    lra_risky_transformations_p = true;
+			    check_and_force_assignment_correctness_p = true;
 			  change_p = true;
 			  /* Invalidate. */
 			  usage_insns[src_regno].check = 0;