2001-10-21 Michael Hope <michaelh@juju.net.nz>

[fw/sdcc] / src / z80 / ralloc.c

diff --git a/src/z80/ralloc.c b/src/z80/ralloc.c
index 7027e57b046406482c7ad96c5045357c91f12929..bc1c337e98af9f7ed13a3c2ab9ab3af07b0b069b 100644 (file)
--- a/src/z80/ralloc.c
+++ b/src/z80/ralloc.c
@@ -45,15 +45,19 @@
 
 #include "z80.h"
 
+/* Flags to turn off optimisations.
+ */
 enum
   {
     DISABLE_PACK_ACC = 0,
     DISABLE_PACK_ASSIGN = 0,
-    DISABLE_PACK_ONE_USE = 0,
+    /* Pack for one use is quite broken. */
+    DISABLE_PACK_ONE_USE = 1,
     DISABLE_PACK_HL = 0,
-    LIMITED_PACK_ACC = 1,
   };
 
+/* Flags to turn on debugging code.
+ */
 enum
   {
     D_ALLOC = 0,
@@ -2032,6 +2036,8 @@ packRegsForHLUse (iCode * ic)
   if (ic->next != uic)
     return;
 
+  if (ic->op == CAST && uic->op == IPUSH)
+    goto hluse;
   if (ic->op == ADDRESS_OF && uic->op == IPUSH)
     goto hluse;
   if (ic->op == CALL && ic->parmBytes == 0 && (uic->op == '-' || uic->op == '+'))
@@ -2046,16 +2052,10 @@ opPreservesA (iCode * ic, iCode * uic)
 {
   if (uic->op == IFX)
     {
+      /* If we've gotten this far then the thing to compare must be
+         small enough and must be in A.
+      */
       return TRUE;
-
-      if (getSize (operandType (IC_COND (uic))) == 1 &&
-          IS_OP_LITERAL (IC_COND (uic)))
-        {
-          return TRUE;
-        }
-
-      D (D_ACCUSE2, ("  + Dropping as operation is an IFX\n"));
-      return FALSE;
     }
 
   if (uic->op == JUMPTABLE)
@@ -2086,50 +2086,10 @@ opPreservesA (iCode * ic, iCode * uic)
       return FALSE;
     }
 
-  /*
-     Bad:
-     !IS_ARITHMETIC_OP(uic) (sub requires A)
-   */
-  if (
-       uic->op != '+' &&
-       !IS_BITWISE_OP (uic) &&
-       uic->op != '=' &&
-       uic->op != EQ_OP &&
-       !POINTER_GET (uic) &&
-  /*
-     uic->op != LEFT_OP &&
-     uic->op != RIGHT_OP && */
-       1
-    )
-    {
-      D (D_ACCUSE2, ("  + Dropping as 'its a bad op'\n"));
-      return FALSE;
-    }
-
-  /* PENDING */
-  if (!IC_LEFT (uic) || !IC_RESULT (ic))
-    {
-      D (D_ACCUSE2, ("  + Dropping for some reason #1\n"));
-      return FALSE;
-    }
-
-/** This is confusing :)  Guess for now */
-  if (IC_LEFT (uic)->key == IC_RESULT (ic)->key &&
-      (IS_ITEMP (IC_RIGHT (uic)) ||
-       (IS_TRUE_SYMOP (IC_RIGHT (uic)))))
-    {
-      return TRUE;
-    }
-
-  if (IC_RIGHT (uic)->key == IC_RESULT (ic)->key &&
-      (IS_ITEMP (IC_LEFT (uic)) ||
-       (IS_TRUE_SYMOP (IC_LEFT (uic)))))
-    {
-      return TRUE;
-    }
-
-  D (D_ACCUSE2, ("  + Dropping as hit default case\n"));
 
+  /* Disabled all of the old rules as they weren't verified and have
+     caused at least one problem.
+   */
   return FALSE;
 }
 
@@ -2244,21 +2204,6 @@ packRegsForAccUse2 (iCode * ic)
       return;
     }
 
-  /* if shift operation make sure right side is not a literal.
-     MLH: depends.
-   */
-#if 0
-  if (ic->op == RIGHT_OP &&
-      (isOperandLiteral (IC_RIGHT (ic)) ||
-       getSize (operandType (IC_RESULT (ic))) > 1))
-    return;
-
-  if (ic->op == LEFT_OP &&
-      (isOperandLiteral (IC_RIGHT (ic)) ||
-       getSize (operandType (IC_RESULT (ic))) > 1))
-    return;
-#endif
-
   /* has only one definition */
   if (bitVectnBitsOn (OP_DEFS (IC_RESULT (ic))) > 1)
     {
@@ -2541,14 +2486,6 @@ packRegisters (eBBlock * ebp)
        packRegsForSupport (ic, ebp);
 #endif
 
-#if 0
-      /* some cases the redundant moves can
-         can be eliminated for return statements */
-      if ((ic->op == RETURN || ic->op == SEND) &&
-         !isOperandInFarSpace (IC_LEFT (ic)) &&
-         !options.model)
-       packRegsForOneuse (ic, IC_LEFT (ic), ebp);
-#endif
       /* if pointer set & left has a size more than
          one and right is not in far space */
       if (!DISABLE_PACK_ONE_USE &&
@@ -2575,6 +2512,7 @@ packRegisters (eBBlock * ebp)
 
          packRegsForOneuse (ic, IC_LEFT (ic), ebp);
        }
+
       /* pack registers for accumulator use, when the result of an
          arithmetic or bit wise operation has only one use, that use is
          immediately following the defintion and the using iCode has
@@ -2586,21 +2524,12 @@ packRegisters (eBBlock * ebp)
        {
          packRegsForHLUse (ic);
        }
-#if 0
-      if ((IS_ARITHMETIC_OP (ic)
-          || IS_BITWISE_OP (ic)
-          || ic->op == LEFT_OP || ic->op == RIGHT_OP
-         ) &&
-         IS_ITEMP (IC_RESULT (ic)) &&
-         getSize (operandType (IC_RESULT (ic))) <= 2)
-       packRegsForAccUse (ic);
-#else
+
       if (!DISABLE_PACK_ACC && IS_ITEMP (IC_RESULT (ic)) &&
          getSize (operandType (IC_RESULT (ic))) == 1)
        {
          packRegsForAccUse2 (ic);
        }
-#endif
     }
 }
 
@@ -2660,8 +2589,10 @@ z80_assignRegisters (eBBlock ** ebbs, int count)
       _G.dataExtend = 0;
     }
 
-  if (options.dump_rassgn)
+  if (options.dump_rassgn) {
     dumpEbbsToFileExt (DUMP_RASSGN, ebbs, count);
+    dumpLiveRanges (DUMP_LRANGE, liveRanges);
+  }
 
   /* after that create the register mask
      for each of the instruction */