nvptx.md (nvptx_reorg_subreg): New fn, broken out of ...

	* config/nvptx/nvptx.md (nvptx_reorg_subreg): New fn, broken out of ...
	(nvptx_reorg): Here.  Keep the non-subreg pieces.

From-SVN: r225154

gcc/ChangeLog

+2015-06-29  Nathan Sidwell  <nathan@codesourcery.com>
+
+	* config/nvptx/nvptx.md (nvptx_reorg_subreg): New fn, broken out of ...
+	(nvptx_reorg): Here.  Keep the non-subreg pieces.
+
 2015-06-29  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* config/gnu-user.h (GNU_USER_TARGET_ENDFILE_SPEC): Use

gcc/config/nvptx/nvptx.c

+
 /* Target code for NVPTX.
    Copyright (C) 2014-2015 Free Software Foundation, Inc.
    Contributed by Bernd Schmidt <bernds@codesourcery.com>
@@ -1877,20 +1878,11 @@ get_replacement (struct reg_replace *r)
    conversion copyin/copyout instructions.  */
 
 static void
-nvptx_reorg (void)
+nvptx_reorg_subreg (void)
 {
   struct reg_replace qiregs, hiregs, siregs, diregs;
   rtx_insn *insn, *next;
 
-  /* We are freeing block_for_insn in the toplev to keep compatibility
-     with old MDEP_REORGS that are not CFG based.  Recompute it now.  */
-  compute_bb_for_insn ();
-
-  df_clear_flags (DF_LR_RUN_DCE);
-  df_analyze ();
-
-  thread_prologue_and_epilogue_insns ();
-
   qiregs.n_allocated = 0;
   hiregs.n_allocated = 0;
   siregs.n_allocated = 0;
@@ -1966,14 +1958,44 @@ nvptx_reorg (void)
 	  validate_change (insn, recog_data.operand_loc[i], new_reg, false);
 	}
     }
+}
 
-  int maxregs = max_reg_num ();
+/* PTX-specific reorganization
+   1) mark now-unused registers, so function begin doesn't declare
+   unused registers.
+   2) replace subregs with suitable sequences.
+*/
+
+static void
+nvptx_reorg (void)
+{
+  struct reg_replace qiregs, hiregs, siregs, diregs;
+  rtx_insn *insn, *next;
+
+  /* We are freeing block_for_insn in the toplev to keep compatibility
+     with old MDEP_REORGS that are not CFG based.  Recompute it now.  */
+  compute_bb_for_insn ();
+
+  thread_prologue_and_epilogue_insns ();
+
+  df_clear_flags (DF_LR_RUN_DCE);
+  df_set_flags (DF_NO_INSN_RESCAN | DF_NO_HARD_REGS);
+  df_analyze ();
   regstat_init_n_sets_and_refs ();
 
-  for (int i = LAST_VIRTUAL_REGISTER + 1; i < maxregs; i++)
+  int max_regs = max_reg_num ();
+
+  /* Mark unused regs as unused.  */
+  for (int i = LAST_VIRTUAL_REGISTER + 1; i < max_regs; i++)
     if (REG_N_SETS (i) == 0 && REG_N_REFS (i) == 0)
       regno_reg_rtx[i] = const0_rtx;
+
+  /* Replace subregs.  */
+  nvptx_reorg_subreg (max_regs);
+
   regstat_free_n_sets_and_refs ();
+
+  df_finish_pass (true);
 }
 
 /* Handle a "kernel" attribute; arguments as in