re PR rtl-optimization/78617 (LRA clobbers live register during rematerialization)

2016-12-07  Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/
    PR rtl-optimization/78617
    * lra-remat.c (do_remat): Initialize live_hard_regs from live in
    registers, also setting hard registers mapped to pseudo registers.

    gcc/testsuite/
    PR rtl-optimization/78617
    * gcc.c-torture/execute/pr78617.c: New test.

From-SVN: r243374

gcc/ChangeLog

+2016-12-07  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+	PR rtl-optimization/78617
+	* lra-remat.c (do_remat): Initialize live_hard_regs from live in
+	registers, also setting hard registers mapped to pseudo registers.
+
 2016-12-07  David Malcolm  <dmalcolm@redhat.com>
 
 	* cfgexpand.c (pass_expand::execute): Move stack initializations

gcc/lra-remat.c

@@ -1047,6 +1047,7 @@ update_scratch_ops (rtx_insn *remat_insn)
 static bool
 do_remat (void)
 {
+  unsigned regno;
   rtx_insn *insn;
   basic_block bb;
   bitmap_head avail_cands;
@@ -1054,12 +1055,21 @@ do_remat (void)
   bool changed_p = false;
   /* Living hard regs and hard registers of living pseudos.  */
   HARD_REG_SET live_hard_regs;
+  bitmap_iterator bi;
 
   bitmap_initialize (&avail_cands, &reg_obstack);
   bitmap_initialize (&active_cands, &reg_obstack);
   FOR_EACH_BB_FN (bb, cfun)
     {
-      REG_SET_TO_HARD_REG_SET (live_hard_regs, df_get_live_out (bb));
+      CLEAR_HARD_REG_SET (live_hard_regs);
+      EXECUTE_IF_SET_IN_BITMAP (df_get_live_in (bb), 0, regno, bi)
+	{
+	  int hard_regno = regno < FIRST_PSEUDO_REGISTER
+			   ? regno
+			   : reg_renumber[regno];
+	  if (hard_regno >= 0)
+	    SET_HARD_REG_BIT (live_hard_regs, hard_regno);
+	}
       bitmap_and (&avail_cands, &get_remat_bb_data (bb)->avin_cands,
 		  &get_remat_bb_data (bb)->livein_cands);
       /* Activating insns are always in the same block as their corresponding

gcc/testsuite/ChangeLog

+2016-12-07  Thomas Preud'homme  <thomas.preudhomme@arm.com>
+
+	PR rtl-optimization/78617
+	* gcc.c-torture/execute/pr78617.c: New test.
+
 2016-12-07  Carl Love  <cel@us.ibm.com>
 
 	* gcc.target/powerpc/builtins-3.c: Move built-in tests for P8 and

gcc/testsuite/gcc.c-torture/execute/pr78617.c

+int a = 0;
+int d = 1;
+int f = 1;
+
+int fn1() {
+  return a || 1 >> a;
+}
+
+int fn2(int p1, int p2) {
+  return p2 >= 2 ? p1 : p1 >> 1;
+}
+
+int fn3(int p1) {
+  return d ^ p1;
+}
+
+int fn4(int p1, int p2) {
+  return fn3(!d > fn2((f = fn1() - 1000) || p2, p1));
+}
+
+int main() {
+  if (fn4(0, 0) != 1)
+    __builtin_abort ();
+  return 0;
+}