PR c/42312

[pf3gnuchains/gcc-fork.git] / gcc / loop-doloop.c

diff --git a/gcc/loop-doloop.c b/gcc/loop-doloop.c
index a039f36..0fa0fe2 100644 (file)
--- a/gcc/loop-doloop.c
+++ b/gcc/loop-doloop.c
@@ -317,7 +317,7 @@ add_test (rtx cond, edge *e, basic_block dest)
       redirect_edge_and_branch_force (*e, dest);
       return false;
     }
-      
+
   JUMP_LABEL (jump) = label;
 
   /* The jump is supposed to handle an unlikely special case.  */
@@ -333,11 +333,14 @@ add_test (rtx cond, edge *e, basic_block dest)
    describes the loop, DESC describes the number of iterations of the
    loop, and DOLOOP_INSN is the low-overhead looping insn to emit at the
    end of the loop.  CONDITION is the condition separated from the
-   DOLOOP_SEQ.  COUNT is the number of iterations of the LOOP.  */
+   DOLOOP_SEQ.  COUNT is the number of iterations of the LOOP.
+   ZERO_EXTEND_P says to zero extend COUNT after the increment of it to
+   word_mode from FROM_MODE.  */
 
 static void
 doloop_modify (struct loop *loop, struct niter_desc *desc,
-              rtx doloop_seq, rtx condition, rtx count)
+              rtx doloop_seq, rtx condition, rtx count,
+              bool zero_extend_p, enum machine_mode from_mode)
 {
   rtx counter_reg;
   rtx tmp, noloop = NULL_RTX;
@@ -411,7 +414,11 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
     }
 
   if (increment_count)
-    count = simplify_gen_binary (PLUS, mode, count, const1_rtx);
+    count = simplify_gen_binary (PLUS, from_mode, count, const1_rtx);
+
+  if (zero_extend_p)
+    count = simplify_gen_unary (ZERO_EXTEND, word_mode,
+                               count, from_mode);
 
   /* Insert initialization of the count register into the loop header.  */
   start_sequence ();
@@ -455,7 +462,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
          set_zero->count = preheader->count;
          set_zero->frequency = preheader->frequency;
        }
- 
+
       if (EDGE_COUNT (set_zero->preds) == 0)
        {
          /* All the conditions were simplified to false, remove the
@@ -470,7 +477,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
          sequence = get_insns ();
          end_sequence ();
          emit_insn_after (sequence, BB_END (set_zero));
-      
+
          set_immediate_dominator (CDI_DOMINATORS, set_zero,
                                   recompute_dominator (CDI_DOMINATORS,
                                                        set_zero));
@@ -523,7 +530,7 @@ doloop_modify (struct loop *loop, struct niter_desc *desc,
   if (true_prob_val)
     {
       /* Seems safer to use the branch probability.  */
-      add_reg_note (jump_insn, REG_BR_PROB, 
+      add_reg_note (jump_insn, REG_BR_PROB,
                    GEN_INT (desc->in_edge->probability));
     }
 }
@@ -547,6 +554,7 @@ doloop_optimize (struct loop *loop)
   struct niter_desc *desc;
   unsigned word_mode_size;
   unsigned HOST_WIDE_INT word_mode_max;
+  bool zero_extend_p = false;
 
   if (dump_file)
     fprintf (dump_file, "Doloop: Processing loop %d.\n", loop->num);
@@ -621,8 +629,7 @@ doloop_optimize (struct loop *loop)
     {
       if (word_mode_size > GET_MODE_BITSIZE (mode))
        {
-         count = simplify_gen_unary (ZERO_EXTEND, word_mode,
-                                     count, mode);
+         zero_extend_p = true;
          iterations = simplify_gen_unary (ZERO_EXTEND, word_mode,
                                           iterations, mode);
          iterations_max = simplify_gen_unary (ZERO_EXTEND, word_mode,
@@ -666,7 +673,8 @@ doloop_optimize (struct loop *loop)
       return false;
     }
 
-  doloop_modify (loop, desc, doloop_seq, condition, count);
+  doloop_modify (loop, desc, doloop_seq, condition, count,
+                zero_extend_p, mode);
   return true;
 }