* config/avr/avr.c (get_sequence_length): Add new function.

	(expand_prologue, expand_epilogue): Remove duplicate code.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@135775 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 102 insertions, 72 deletions

diff --git a/gcc/config/avr/avr.c b/gcc/config/avr/avr.c
index 1293a4b3463..012a7e4fd1b 100644
--- a/gcc/config/avr/avr.c
+++ b/gcc/config/avr/avr.c
@@ -54,6 +54,7 @@ static int signal_function_p (tree);
 static int avr_OS_task_function_p (tree);
 static int avr_OS_main_function_p (tree);
 static int avr_regs_to_save (HARD_REG_SET *);
+static int get_sequence_length (rtx insns);
 static int sequent_regs_live (void);
 static const char *ptrreg_to_str (int);
 static const char *cond_string (enum rtx_code);
@@ -585,6 +586,20 @@ sequent_regs_live (void)
   return (cur_seq == live_seq) ? live_seq : 0;
 }
 
+/* Obtain the length sequence of insns.  */
+
+int
+get_sequence_length (rtx insns)
+{
+  rtx insn;
+  int length;
+  
+  for (insn = insns, length = 0; insn; insn = NEXT_INSN (insn))
+    length += get_attr_length (insn);
+		
+  return length;
+}
+
 /*  Output function prologue.  */
 
 void
@@ -718,12 +733,11 @@ expand_prologue (void)
               To avoid a complex logic, both methods are tested and shortest
               is selected.  */
               rtx myfp;
-              /*  First method.  */
+	      rtx fp_plus_insns; 
+	      rtx sp_plus_insns = NULL_RTX;
+
               if (TARGET_TINY_STACK)
                 {
-                  if (size < -63 || size > 63)
-                    warning (0, "large frame pointer change (%d) with -mtiny-stack", size);
-                    
                   /* The high byte (r29) doesn't change - prefer 'subi' (1 cycle)
                      over 'sbiw' (2 cycles, same size).  */
                   myfp = gen_rtx_REG (QImode, REGNO (frame_pointer_rtx));
@@ -733,51 +747,53 @@ expand_prologue (void)
                   /*  Normal sized addition.  */
                   myfp = frame_pointer_rtx;
                 }
-              /* Calculate length.  */ 
-              int method1_length;
-              method1_length =
-	        get_attr_length (gen_move_insn (frame_pointer_rtx, stack_pointer_rtx));
-              method1_length +=
-	        get_attr_length (gen_move_insn (myfp, 
-                                                gen_rtx_PLUS (GET_MODE(myfp), myfp,
-                                                              gen_int_mode (-size, 
-							                    GET_MODE(myfp)))));
-              method1_length += 
-	        get_attr_length (gen_move_insn (stack_pointer_rtx, frame_pointer_rtx));
-              
+
+	      /* Method 1-Adjust frame pointer.  */
+	      start_sequence ();
+
+              insn = emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
+              RTX_FRAME_RELATED_P (insn) = 1;
+
+              insn = 
+	        emit_move_insn (myfp,
+				gen_rtx_PLUS (GET_MODE(myfp), myfp, 
+					      gen_int_mode (-size, 
+							    GET_MODE(myfp))));
+              RTX_FRAME_RELATED_P (insn) = 1;
+
+              insn = emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
+              RTX_FRAME_RELATED_P (insn) = 1;
+
+	      fp_plus_insns = get_insns ();
+	      end_sequence ();
+
 	      /* Method 2-Adjust Stack pointer.  */
-              int sp_plus_length = 0;
               if (size <= 6)
                 {
-                  sp_plus_length = 
-		    get_attr_length (gen_move_insn (stack_pointer_rtx,
-                                                    gen_rtx_PLUS (HImode, stack_pointer_rtx,
-                                                                  gen_int_mode (-size, 
-								                HImode))));
-		  sp_plus_length += 
-		    get_attr_length (gen_move_insn (frame_pointer_rtx, stack_pointer_rtx));
+		  start_sequence ();
+
+		  insn = 
+		    emit_move_insn (stack_pointer_rtx,
+				    gen_rtx_PLUS (HImode, 
+						  stack_pointer_rtx, 
+						  gen_int_mode (-size, 
+								HImode)));
+		  RTX_FRAME_RELATED_P (insn) = 1;
+		  
+		  insn = 
+		    emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
+		  RTX_FRAME_RELATED_P (insn) = 1;
+
+		  sp_plus_insns = get_insns ();
+		  end_sequence ();
                 }
+
               /* Use shortest method.  */
-              if (size <= 6 && (sp_plus_length < method1_length))
-                {
-                  insn = emit_move_insn (stack_pointer_rtx,
-                                         gen_rtx_PLUS (HImode, stack_pointer_rtx, 
-                                                       gen_int_mode (-size, HImode)));
-                  RTX_FRAME_RELATED_P (insn) = 1;
-		  insn = emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
-                  RTX_FRAME_RELATED_P (insn) = 1;
-                }
+              if (size <= 6 && (get_sequence_length (sp_plus_insns) 
+				 < get_sequence_length (fp_plus_insns)))
+		emit_insn (sp_plus_insns);
               else
-                {		
-                  insn = emit_move_insn (frame_pointer_rtx, stack_pointer_rtx);
-                  RTX_FRAME_RELATED_P (insn) = 1;
-                  insn = emit_move_insn (myfp,
-                                         gen_rtx_PLUS (GET_MODE(myfp), myfp, 
-                                                       gen_int_mode (-size, GET_MODE(myfp))));
-                  RTX_FRAME_RELATED_P (insn) = 1;
-                  insn = emit_move_insn ( stack_pointer_rtx, frame_pointer_rtx);
-                  RTX_FRAME_RELATED_P (insn) = 1;
-                }
+		emit_insn (fp_plus_insns);
             }
         }
     }
@@ -872,42 +888,56 @@ expand_epilogue (void)
 	  if (size)
 	    {
               /* Try two methods to adjust stack and select shortest.  */
-              int fp_plus_length;
+	      rtx myfp;
+	      rtx fp_plus_insns;
+	      rtx sp_plus_insns = NULL_RTX;
+	      
+	      if (TARGET_TINY_STACK)
+                {
+                  /* The high byte (r29) doesn't change - prefer 'subi' 
+                     (1 cycle) over 'sbiw' (2 cycles, same size).  */
+                  myfp = gen_rtx_REG (QImode, REGNO (frame_pointer_rtx));
+                }
+              else 
+                {
+                  /* Normal sized addition.  */
+                  myfp = frame_pointer_rtx;
+                }
+	      
               /* Method 1-Adjust frame pointer.  */
-              fp_plus_length = 
-	        get_attr_length (gen_move_insn (frame_pointer_rtx,
-                                                gen_rtx_PLUS (HImode, frame_pointer_rtx,
-                                                              gen_int_mode (size,
-									    HImode))));
-              /* Copy to stack pointer.  */
-              fp_plus_length += 
-	        get_attr_length (gen_move_insn (stack_pointer_rtx, frame_pointer_rtx));    
-          
+	      start_sequence ();
+
+	      emit_move_insn (myfp,
+			      gen_rtx_PLUS (HImode, myfp,
+					    gen_int_mode (size, 
+							  GET_MODE(myfp))));
+
+	      /* Copy to stack pointer.  */
+	      emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
+
+	      fp_plus_insns = get_insns ();
+	      end_sequence ();	      
+
               /* Method 2-Adjust Stack pointer.  */
-              int sp_plus_length = 0;
               if (size <= 5)
                 {
-                  sp_plus_length = 
-		    get_attr_length (gen_move_insn (stack_pointer_rtx,
-                                                    gen_rtx_PLUS (HImode, stack_pointer_rtx,
-                                                                  gen_int_mode (size,
-										HImode))));
+		  start_sequence ();
+
+		  emit_move_insn (stack_pointer_rtx,
+				  gen_rtx_PLUS (HImode, stack_pointer_rtx,
+						gen_int_mode (size, 
+							      HImode)));
+
+		  sp_plus_insns = get_insns ();
+		  end_sequence ();
                 }
+
               /* Use shortest method.  */
-              if (size <= 5 && (sp_plus_length < fp_plus_length))
-                {
-                  emit_move_insn (stack_pointer_rtx,
-                                  gen_rtx_PLUS (HImode, stack_pointer_rtx,
-                                                gen_int_mode (size, HImode)));
-                }
+              if (size <= 5 && (get_sequence_length (sp_plus_insns) 
+				 < get_sequence_length (fp_plus_insns)))
+	      	emit_insn (sp_plus_insns);
               else
-                {
-                  emit_move_insn (frame_pointer_rtx,
-                                  gen_rtx_PLUS (HImode, frame_pointer_rtx,
-                                                gen_int_mode (size, HImode)));
-                  /* Copy to stack pointer.  */
-                  emit_move_insn (stack_pointer_rtx, frame_pointer_rtx);
-                }
+		emit_insn (fp_plus_insns);
             }
 	  if (!(cfun->machine->is_OS_task || cfun->machine->is_OS_main))
 	    {