re PR target/83252 (Wrong code with "-march=skylake-avx512 -O3")

2017-12-07  Vladimir Makarov  <vmakarov@redhat.com>

	PR target/83252
	PR rtl-optimization/80818
	* lra.c (add_regs_to_insn_regno_info): Make a hard reg in CLOBBER
	always early clobbered.
	* lra-lives.c (process_bb_lives): Check input hard regs for early
	clobbered non-operand hard reg.

From-SVN: r255471

gcc/ChangeLog

+2017-12-07  Vladimir Makarov  <vmakarov@redhat.com>
+
+	PR target/83252
+	PR rtl-optimization/80818
+	* lra.c (add_regs_to_insn_regno_info): Make a hard reg in CLOBBER
+	always early clobbered.
+	* lra-lives.c (process_bb_lives): Check input hard regs for early
+	clobbered non-operand hard reg.
+
 2017-12-07  Jakub Jelinek  <jakub@redhat.com>
 
 	PR middle-end/83164

gcc/lra-lives.c

@@ -928,7 +928,18 @@ process_bb_lives (basic_block bb, int &curr_point, bool dead_insn_p)
       for (reg = curr_static_id->hard_regs; reg != NULL; reg = reg->next)
 	if (reg->type == OP_OUT
 	    && reg_early_clobber_p (reg, n_alt) && ! reg->subreg_p)
-	  make_hard_regno_dead (reg->regno);
+	  {
+	    struct lra_insn_reg *reg2;
+	    
+	    /* We can have early clobbered non-operand hard reg and
+	       the same hard reg as an insn input.  Don't make hard
+	       reg dead before the insns.  */
+	    for (reg2 = curr_id->regs; reg2 != NULL; reg2 = reg2->next)
+	      if (reg2->type != OP_OUT && reg2->regno == reg->regno)
+		break;
+	    if (reg2 == NULL)
+	      make_hard_regno_dead (reg->regno);
+	  }
 
       if (need_curr_point_incr)
 	next_program_point (curr_point, freq);

gcc/lra.c

@@ -1476,15 +1476,11 @@ add_regs_to_insn_regno_info (lra_insn_recog_data_t data, rtx x,
       add_regs_to_insn_regno_info (data, SET_SRC (x), insn, OP_IN, false, 0);
       break;
     case CLOBBER:
-      {
-	int code = INSN_CODE (insn);
-
-	/* We treat clobber of non-operand hard registers as early
-	   clobber (the behavior is expected from asm).  */
-	add_regs_to_insn_regno_info (data, XEXP (x, 0), insn, OP_OUT,
-				     code < 0, code < 0 ? ALL_ALTERNATIVES : 0);
-	break;
-      }
+      /* We treat clobber of non-operand hard registers as early
+	 clobber.  */
+      add_regs_to_insn_regno_info (data, XEXP (x, 0), insn, OP_OUT,
+				   true, ALL_ALTERNATIVES);
+      break;
     case PRE_INC: case PRE_DEC: case POST_INC: case POST_DEC:
       add_regs_to_insn_regno_info (data, XEXP (x, 0), insn, OP_INOUT, false, 0);
       break;