* config/bfin/bfin.c (bfin_optimize_loop): If we need a scratch reg,

	scan backwards to try to find a constant to initialize it.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@146974 138bc75d-0d04-0410-961f-82ee72b054a4

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3c18dfc..8f8e05d 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2009-04-29  Bernd Schmidt  <bernd.schmidt@analog.com>
+
+       * config/bfin/bfin.c (bfin_optimize_loop): If we need a scratch reg,
+       scan backwards to try to find a constant to initialize it.
+

 2009-04-29  Richard Guenther  <rguenther@suse.de>
 
        PR middle-end/39937
 2009-04-29  Richard Guenther  <rguenther@suse.de>
 
        PR middle-end/39937

diff --git a/gcc/config/bfin/bfin.c b/gcc/config/bfin/bfin.c
index 14f7f51..0808522 100644 (file)
--- a/gcc/config/bfin/bfin.c
+++ b/gcc/config/bfin/bfin.c
@@ -3784,7 +3784,7 @@ bfin_optimize_loop (loop_info loop)
   rtx insn, last_insn;
   rtx loop_init, start_label, end_label;
   rtx reg_lc0, reg_lc1, reg_lt0, reg_lt1, reg_lb0, reg_lb1;
   rtx insn, last_insn;
   rtx loop_init, start_label, end_label;
   rtx reg_lc0, reg_lc1, reg_lt0, reg_lt1, reg_lb0, reg_lb1;

-  rtx iter_reg, scratchreg;
+  rtx iter_reg, scratchreg, scratch_init, scratch_init_insn;

   rtx lc_reg, lt_reg, lb_reg;
   rtx seq, seq_end;
   int length;
   rtx lc_reg, lt_reg, lb_reg;
   rtx seq, seq_end;
   int length;


@@ -3838,18 +3838,40 @@ bfin_optimize_loop (loop_info loop)
       goto bad_loop;
     }
   scratchreg = NULL_RTX;
       goto bad_loop;
     }
   scratchreg = NULL_RTX;

+  scratch_init = iter_reg;
+  scratch_init_insn = NULL_RTX;

   if (!PREG_P (iter_reg) && loop->incoming_src)
     {
   if (!PREG_P (iter_reg) && loop->incoming_src)
     {

+      basic_block bb_in = loop->incoming_src;

       int i;
       for (i = REG_P0; i <= REG_P5; i++)
        if ((df_regs_ever_live_p (i)
             || (funkind (TREE_TYPE (current_function_decl)) == SUBROUTINE
                 && call_used_regs[i]))
       int i;
       for (i = REG_P0; i <= REG_P5; i++)
        if ((df_regs_ever_live_p (i)
             || (funkind (TREE_TYPE (current_function_decl)) == SUBROUTINE
                 && call_used_regs[i]))

-           && !REGNO_REG_SET_P (df_get_live_out (loop->incoming_src), i))
+           && !REGNO_REG_SET_P (df_get_live_out (bb_in), i))

          {
            scratchreg = gen_rtx_REG (SImode, i);
            break;
          }
          {
            scratchreg = gen_rtx_REG (SImode, i);
            break;
          }

+      for (insn = BB_END (bb_in); insn != BB_HEAD (bb_in);
+          insn = PREV_INSN (insn))
+       {
+         rtx set;
+         if (NOTE_P (insn) || BARRIER_P (insn))
+           continue;
+         set = single_set (insn);
+         if (set && rtx_equal_p (SET_DEST (set), iter_reg))
+           {
+             if (CONSTANT_P (SET_SRC (set)))
+               {
+                 scratch_init = SET_SRC (set);
+                 scratch_init_insn = insn;
+               }
+             break;
+           }
+         else if (reg_mentioned_p (iter_reg, PATTERN (insn)))
+           break;
+       }

     }
 
   if (loop->incoming_src)
     }
 
   if (loop->incoming_src)


@@ -4092,11 +4114,13 @@ bfin_optimize_loop (loop_info loop)
     }
   else if (scratchreg != NULL_RTX)
     {
     }
   else if (scratchreg != NULL_RTX)
     {

-      emit_insn (gen_movsi (scratchreg, iter_reg));
+      emit_insn (gen_movsi (scratchreg, scratch_init));

       loop_init = gen_lsetup_with_autoinit (lt_reg, start_label,
                                            lb_reg, end_label,
                                            lc_reg, scratchreg);
       seq_end = emit_insn (loop_init);
       loop_init = gen_lsetup_with_autoinit (lt_reg, start_label,
                                            lb_reg, end_label,
                                            lc_reg, scratchreg);
       seq_end = emit_insn (loop_init);

+      if (scratch_init_insn != NULL_RTX)
+       delete_insn (scratch_init_insn);

     }
   else
     {
     }
   else
     {


@@ -4106,12 +4130,14 @@ bfin_optimize_loop (loop_info loop)
       rtx pop = gen_frame_mem (SImode,
                               gen_rtx_POST_INC (SImode, stack_pointer_rtx));
       emit_insn (gen_movsi (push, p0reg));
       rtx pop = gen_frame_mem (SImode,
                               gen_rtx_POST_INC (SImode, stack_pointer_rtx));
       emit_insn (gen_movsi (push, p0reg));

-      emit_insn (gen_movsi (p0reg, iter_reg));
+      emit_insn (gen_movsi (p0reg, scratch_init));

       loop_init = gen_lsetup_with_autoinit (lt_reg, start_label,
                                            lb_reg, end_label,
                                            lc_reg, p0reg);
       emit_insn (loop_init);
       seq_end = emit_insn (gen_movsi (p0reg, pop));
       loop_init = gen_lsetup_with_autoinit (lt_reg, start_label,
                                            lb_reg, end_label,
                                            lc_reg, p0reg);
       emit_insn (loop_init);
       seq_end = emit_insn (gen_movsi (p0reg, pop));

+      if (scratch_init_insn != NULL_RTX)
+       delete_insn (scratch_init_insn);

     }
 
   if (dump_file)
     }
 
   if (dump_file)