* src/pic16/gen.{c,h}: s/mov2f/pic16_mov2f made public
[fw/sdcc] / src / pic16 / genarith.c
index fdac37b0de04ce418e1f29f61e26cf25b0ffd84c..1a556baf0f959f395cf5f08769f9caeb05cee9dc 100644 (file)
@@ -416,6 +416,7 @@ static void adjustArithmeticResult(iCode *ic)
 }
 #endif
 
+#if 0
 /*-----------------------------------------------------------------*/
 /* genAddlit - generates code for addition                         */
 /*-----------------------------------------------------------------*/
@@ -438,6 +439,7 @@ static void genAddLit2byte (operand *result, int offr, int lit)
   }
 
 }
+#endif
 
 static void emitMOVWF(operand *reg, int offset)
 {
@@ -456,19 +458,90 @@ static void emitMOVWF(operand *reg, int offset)
 static void genAddLit (iCode *ic, int lit)
 {
 
-  int size,same;
-  int lo;
+  int size,sizeL,same;
+  int i, llit;
 
   operand *result;
   operand *left;
+  sym_link *lleft;
 
     FENTRY;
 
 
   left = IC_LEFT(ic);
+  lleft = operandType (left);
   result = IC_RESULT(ic);
   same = pic16_sameRegs(AOP(left), AOP(result));
   size = pic16_getDataSize(result);
+  sizeL = pic16_getDataSize(left);
+  llit = lit;
+
+#define MIN(a,b)       (((a) < (b)) ? (a) : (b))
+  /* move left to result -- possibly sign extend */
+  for (i=0; i < MIN(size, sizeL); i++) {
+    pic16_mov2f (AOP(result), AOP(left), i);
+  } // for i
+#undef MIN
+
+  /* extend to result size */
+  if (IS_UNSIGNED(lleft)) {
+    /* zero-extend */
+    for (i = sizeL; i < size; i++) {
+      pic16_emitpcode (POC_CLRF, pic16_popGet (AOP(result), i));
+    } // for i
+  } else {
+    /* sign-extend */
+    if (size == sizeL + 1) {
+      pic16_emitpcode (POC_CLRF, pic16_popGet (AOP(result), sizeL));
+      pic16_emitpcode (POC_BTFSC, pic16_newpCodeOpBit_simple (AOP(left),sizeL-1,7));
+      pic16_emitpcode (POC_SETF, pic16_popGet (AOP(result), sizeL));
+    } else {
+      pic16_emitpcode (POC_CLRF, pic16_popCopyReg (&pic16_pc_wreg));
+      pic16_emitpcode (POC_BTFSC, pic16_newpCodeOpBit_simple (AOP(left),sizeL-1,7));
+      pic16_emitpcode (POC_SETF, pic16_popCopyReg (&pic16_pc_wreg));
+      
+      for (i=sizeL; i < size; i++) {
+        pic16_emitpcode (POC_MOVWF, pic16_popGet (AOP(result), i));
+      } // for i
+    } // if
+  } // if (SIGNED)
+
+  /* special cases */
+  if (lit == 0) {
+    /* nothing to do */
+  } else if (lit == 1) {
+    switch (size) {
+    case 1:
+      /* handled below */
+      break;
+    case 2:
+      pic16_emitpcode (POC_INFSNZ, pic16_popGet (AOP(result), 0));
+      break;
+    default:
+      assert (size > 2);
+      pic16_emitpcode (POC_INCF, pic16_popGet(AOP(result), 0));
+      for (i=1; i < size-1; i++) {
+        emitSKPNC; /* a jump here saves up to 2(size-2)cycles */
+        pic16_emitpcode (POC_INCF, pic16_popGet(AOP(result), i));
+      } // for i
+      emitSKPNC;
+      break;
+    } // switch
+    
+    pic16_emitpcode (POC_INCF, pic16_popGet (AOP(result), size-1));
+  } else {
+    /* general case */
+
+    /* add literal to result */
+    for (i=0; i < size; i++) {
+      pic16_emitpcode (POC_MOVLW, pic16_popGetLit (llit));
+      llit >>= 8; /* FIXME: arithmetic right shift for signed literals? */
+      pic16_emitpcode (i == 0 ? POC_ADDWF : POC_ADDWFC,
+       pic16_popGet (AOP(result), i));
+    }
+  }
+
+#if 0
 
   if(same) {
 
@@ -739,6 +812,7 @@ static void genAddLit (iCode *ic, int lit)
       }
     }
   }
+#endif
 }
 
 /*-----------------------------------------------------------------*/
@@ -767,8 +841,8 @@ void pic16_genPlus (iCode *ic)
 
        if ( (AOP_TYPE(left) == AOP_LIT) || (pic16_sameRegs(AOP(right), AOP(result))) ) {
                operand *t = right;
-               right = left;
-               left = t;
+               right = IC_RIGHT(ic) = left;
+               left = IC_LEFT(ic) = t;
        }
 
        /* if both left & right are in bit space */
@@ -790,11 +864,15 @@ void pic16_genPlus (iCode *ic)
                                pic16_emitpcode(POC_XORWF, pic16_popGet(AOP(result),0));
                        }
                } else {
+                       unsigned long lit = (unsigned long)floatFromVal (AOP(right)->aopu.aop_lit);
                        size = pic16_getDataSize(result);
                        while (size--) {
-                               MOVA(pic16_aopGet(AOP(right),offset,FALSE,FALSE));  
-                               pic16_emitcode("addc","a,#00  ;%d",__LINE__);
-                               pic16_aopPut(AOP(result),"a",offset++);
+                               pic16_emitpcode (POC_CLRF, pic16_popGet (AOP(result), offset));
+                               pic16_emitpcode (POC_MOVLW, pic16_popGetLit ((lit >> (8*offset)) & 0xFF));
+                               pic16_emitpcode (POC_ADDWFC, pic16_popGet(AOP(result), offset++));
+                               //MOVA(pic16_aopGet(AOP(right),offset,FALSE,FALSE));  
+                               //pic16_emitcode("addc","a,#00  ;%d",__LINE__);
+                               //pic16_aopPut(AOP(result),"a",offset++);
                        }
                }
        goto release ;
@@ -805,12 +883,12 @@ void pic16_genPlus (iCode *ic)
        if (pic16_genPlusIncr (ic) == TRUE)
                goto release;   
 
-       size = pic16_getDataSize(IC_RESULT(ic));
+       size = pic16_getDataSize(result);
 
-       if(AOP(IC_RIGHT(ic))->type == AOP_LIT) {
+       if(AOP(right)->type == AOP_LIT) {
                /* Add a literal to something else */
                //bool know_W=0;
-               unsigned lit = (unsigned) floatFromVal(AOP(IC_RIGHT(ic))->aopu.aop_lit);
+               unsigned lit = (unsigned) floatFromVal(AOP(right)->aopu.aop_lit);
                //unsigned l1=0;
 
                //offset = 0;
@@ -819,55 +897,55 @@ void pic16_genPlus (iCode *ic)
                genAddLit (ic,  lit);
                goto release;
 
-       } else if(AOP_TYPE(IC_RIGHT(ic)) == AOP_CRY) {
+       } else if(AOP_TYPE(right) == AOP_CRY) {
 
-               pic16_emitcode(";bitadd","right is bit: %s",pic16_aopGet(AOP(IC_RIGHT(ic)),0,FALSE,FALSE));
-               pic16_emitcode(";bitadd","left is bit: %s",pic16_aopGet(AOP(IC_LEFT(ic)),0,FALSE,FALSE));
-               pic16_emitcode(";bitadd","result is bit: %s",pic16_aopGet(AOP(IC_RESULT(ic)),0,FALSE,FALSE));
+               pic16_emitcode(";bitadd","right is bit: %s",pic16_aopGet(AOP(right),0,FALSE,FALSE));
+               pic16_emitcode(";bitadd","left is bit: %s",pic16_aopGet(AOP(left),0,FALSE,FALSE));
+               pic16_emitcode(";bitadd","result is bit: %s",pic16_aopGet(AOP(result),0,FALSE,FALSE));
 
                /* here we are adding a bit to a char or int */
                if(size == 1) {
-                       if (pic16_sameRegs(AOP(IC_LEFT(ic)), AOP(IC_RESULT(ic))) ) {
+                       if (pic16_sameRegs(AOP(left), AOP(result)) ) {
 
-                               pic16_emitpcode(POC_BTFSC , pic16_popGet(AOP(IC_RIGHT(ic)),0));
-                               pic16_emitpcode(POC_INCF ,  pic16_popGet(AOP(IC_RESULT(ic)),0));
+                               pic16_emitpcode(POC_BTFSC , pic16_popGet(AOP(right),0));
+                               pic16_emitpcode(POC_INCF ,  pic16_popGet(AOP(result),0));
 
                                pic16_emitcode("btfsc","(%s >> 3), (%s & 7)",
-                                               AOP(IC_RIGHT(ic))->aopu.aop_dir,
-                                               AOP(IC_RIGHT(ic))->aopu.aop_dir);
-                               pic16_emitcode(" incf","%s,f", pic16_aopGet(AOP(IC_RESULT(ic)),0,FALSE,FALSE));
+                                               AOP(right)->aopu.aop_dir,
+                                               AOP(right)->aopu.aop_dir);
+                               pic16_emitcode(" incf","%s,f", pic16_aopGet(AOP(result),0,FALSE,FALSE));
                        } else { // not same
 
-                               if(AOP_TYPE(IC_LEFT(ic)) == AOP_ACC) {
-                                       pic16_emitpcode(POC_BTFSC , pic16_popGet(AOP(IC_RIGHT(ic)),0));
+                               if(AOP_TYPE(left) == AOP_ACC) {
+                                       pic16_emitpcode(POC_BTFSC , pic16_popGet(AOP(right),0));
                                        pic16_emitpcode(POC_XORLW , pic16_popGetLit(1));
 
                                        pic16_emitcode("btfsc","(%s >> 3), (%s & 7)",
-                                       AOP(IC_RIGHT(ic))->aopu.aop_dir,
-                                       AOP(IC_RIGHT(ic))->aopu.aop_dir);
+                                       AOP(right)->aopu.aop_dir,
+                                       AOP(right)->aopu.aop_dir);
                                        pic16_emitcode(" xorlw","1");
                                } else {
-                                       pic16_mov2w(AOP(IC_LEFT(ic)),0);
-                                       pic16_emitpcode(POC_BTFSC , pic16_popGet(AOP(IC_RIGHT(ic)),0));
-                                       pic16_emitpcode(POC_INCFW , pic16_popGet(AOP(IC_LEFT(ic)),0));
+                                       pic16_mov2w(AOP(left),0);
+                                       pic16_emitpcode(POC_BTFSC , pic16_popGet(AOP(right),0));
+                                       pic16_emitpcode(POC_INCFW , pic16_popGet(AOP(left),0));
 
-                                       pic16_emitcode("movf","%s,w", pic16_aopGet(AOP(IC_LEFT(ic)),0,FALSE,FALSE));
+                                       pic16_emitcode("movf","%s,w", pic16_aopGet(AOP(left),0,FALSE,FALSE));
                                        pic16_emitcode("btfsc","(%s >> 3), (%s & 7)",
-                                       AOP(IC_RIGHT(ic))->aopu.aop_dir,
-                                       AOP(IC_RIGHT(ic))->aopu.aop_dir);
-                                       pic16_emitcode(" incf","%s,w", pic16_aopGet(AOP(IC_LEFT(ic)),0,FALSE,FALSE));
+                                       AOP(right)->aopu.aop_dir,
+                                       AOP(right)->aopu.aop_dir);
+                                       pic16_emitcode(" incf","%s,w", pic16_aopGet(AOP(left),0,FALSE,FALSE));
                                }
          
-                               if(AOP_TYPE(IC_RESULT(ic)) != AOP_ACC) {
+                               if(AOP_TYPE(result) != AOP_ACC) {
            
-                                       if(AOP_TYPE(IC_RESULT(ic)) == AOP_CRY) {
+                                       if(AOP_TYPE(result) == AOP_CRY) {
                                                pic16_emitpcode(POC_ANDLW , pic16_popGetLit(1));
-                                               pic16_emitpcode(POC_BCF ,   pic16_popGet(AOP(IC_RESULT(ic)),0));
+                                               pic16_emitpcode(POC_BCF ,   pic16_popGet(AOP(result),0));
                                                emitSKPZ;
-                                               pic16_emitpcode(POC_BSF ,   pic16_popGet(AOP(IC_RESULT(ic)),0));
+                                               pic16_emitpcode(POC_BSF ,   pic16_popGet(AOP(result),0));
                                        } else {
-                                               pic16_emitpcode(POC_MOVWF ,   pic16_popGet(AOP(IC_RESULT(ic)),0));
-                                               pic16_emitcode("movwf","%s", pic16_aopGet(AOP(IC_RESULT(ic)),0,FALSE,FALSE));
+                                               pic16_emitpcode(POC_MOVWF ,   pic16_popGet(AOP(result),0));
+                                               pic16_emitcode("movwf","%s", pic16_aopGet(AOP(result),0,FALSE,FALSE));
                                        }
                                }
                        }
@@ -875,39 +953,39 @@ void pic16_genPlus (iCode *ic)
                } else {
                        int offset = 1;
                        DEBUGpic16_emitcode ("; ***","%s  %d",__FUNCTION__,__LINE__);
-                       if (pic16_sameRegs(AOP(IC_LEFT(ic)), AOP(IC_RESULT(ic))) ) {
+                       if (pic16_sameRegs(AOP(left), AOP(result)) ) {
                                emitCLRZ;
-                               pic16_emitpcode(POC_BTFSC, pic16_popGet(AOP(IC_RIGHT(ic)),0));
-                               pic16_emitpcode(POC_INCF,  pic16_popGet(AOP(IC_RESULT(ic)),0));
+                               pic16_emitpcode(POC_BTFSC, pic16_popGet(AOP(right),0));
+                               pic16_emitpcode(POC_INCF,  pic16_popGet(AOP(result),0));
 
                                pic16_emitcode("clrz","");
 
                                pic16_emitcode("btfsc","(%s >> 3), (%s & 7)",
-                                               AOP(IC_RIGHT(ic))->aopu.aop_dir,
-                                               AOP(IC_RIGHT(ic))->aopu.aop_dir);
-                               pic16_emitcode(" incf","%s,f", pic16_aopGet(AOP(IC_RESULT(ic)),0,FALSE,FALSE));
+                                               AOP(right)->aopu.aop_dir,
+                                               AOP(right)->aopu.aop_dir);
+                               pic16_emitcode(" incf","%s,f", pic16_aopGet(AOP(result),0,FALSE,FALSE));
 
                        } else {
                                emitCLRZ; // needed here as well: INCFW is not always executed, Z is undefined then
-                               pic16_mov2w(AOP(IC_LEFT(ic)),0);
-                               pic16_emitpcode(POC_BTFSC, pic16_popGet(AOP(IC_RIGHT(ic)),0));
-                               pic16_emitpcode(POC_INCFW, pic16_popGet(AOP(IC_LEFT(ic)),0));
-                               //pic16_emitpcode(POC_MOVWF, pic16_popGet(AOP(IC_RIGHT(ic)),0,FALSE,FALSE));
-                               emitMOVWF(IC_RIGHT(ic),0);
+                               pic16_mov2w(AOP(left),0);
+                               pic16_emitpcode(POC_BTFSC, pic16_popGet(AOP(right),0));
+                               pic16_emitpcode(POC_INCFW, pic16_popGet(AOP(left),0));
+                               //pic16_emitpcode(POC_MOVWF, pic16_popGet(AOP(right),0,FALSE,FALSE));
+                               emitMOVWF(right,0);
 
-                               pic16_emitcode("movf","%s,w", pic16_aopGet(AOP(IC_LEFT(ic)),0,FALSE,FALSE));
+                               pic16_emitcode("movf","%s,w", pic16_aopGet(AOP(left),0,FALSE,FALSE));
                                pic16_emitcode("btfsc","(%s >> 3), (%s & 7)",
-                                               AOP(IC_RIGHT(ic))->aopu.aop_dir,
-                                               AOP(IC_RIGHT(ic))->aopu.aop_dir);
-                               pic16_emitcode(" incf","%s,w", pic16_aopGet(AOP(IC_LEFT(ic)),0,FALSE,FALSE));
-                               pic16_emitcode("movwf","%s", pic16_aopGet(AOP(IC_RESULT(ic)),0,FALSE,FALSE));
+                                               AOP(right)->aopu.aop_dir,
+                                               AOP(right)->aopu.aop_dir);
+                               pic16_emitcode(" incf","%s,w", pic16_aopGet(AOP(left),0,FALSE,FALSE));
+                               pic16_emitcode("movwf","%s", pic16_aopGet(AOP(result),0,FALSE,FALSE));
 
                        }
 
                        while(--size){
                                emitSKPZ;
-                               pic16_emitpcode(POC_INCF,  pic16_popGet(AOP(IC_RESULT(ic)),offset++));
-                               //pic16_emitcode(" incf","%s,f", pic16_aopGet(AOP(IC_RIGHT(ic)),offset++,FALSE,FALSE));
+                               pic16_emitpcode(POC_INCF,  pic16_popGet(AOP(result),offset++));
+                               //pic16_emitcode(" incf","%s,f", pic16_aopGet(AOP(right),offset++,FALSE,FALSE));
                        }
 
                }
@@ -1013,6 +1091,44 @@ void pic16_genPlus (iCode *ic)
                                }
                        }
 
+                       // add leftover bytes
+                       // either left or right is too short
+                       for (i=size; i < AOP_SIZE(result); i++) {
+                         // get right operand into WREG
+                         if (i < AOP_SIZE(right)) {
+                           pic16_mov2w (AOP(right), i);
+                         } else {
+                           // right is too short
+                           pic16_emitpcode (POC_CLRF, pic16_popCopyReg (&pic16_pc_wreg));
+                           if (!SPEC_USIGN(getSpec(operandType(right)))) {
+                             // right operand is signed
+                             pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(right),AOP_SIZE(right)-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
+                             pic16_emitpcode(POC_COMF, pic16_popCopyReg (&pic16_pc_wreg));
+                           }
+                         }
+
+                         // get left+WREG+CARRY into result
+                         if (i < AOP_SIZE(left)) {
+                           if (pic16_sameRegs (AOP(left), AOP(result))) {
+                             pic16_emitpcode (POC_ADDWFC, pic16_popGet (AOP(result), i));
+                           } else {
+                             pic16_emitpcode (POC_ADDFWC, pic16_popGet (AOP(left), i));
+                             pic16_emitpcode(POC_MOVWF, pic16_popGet(AOP(result),i));
+                           }
+                         } else {
+                           // left is too short
+                           pic16_emitpcode (POC_CLRF, pic16_popGet (AOP(result), i));
+                           if (!SPEC_USIGN(getSpec(operandType(left)))) {
+                             // left operand is signed
+                             pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(left),AOP_SIZE(left)-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
+                             pic16_emitpcode(POC_COMF, pic16_popGet (AOP(result), i));
+                           }
+                           pic16_emitpcode (POC_ADDWFC, pic16_popGet (AOP(result), i));
+                         }
+                       } // for i
+                       goto release;
+                       
+#if 0
                        // add leftover bytes
                        if (SPEC_USIGN(getSpec(operandType(right)))) {
                                // right is unsigned
@@ -1048,6 +1164,7 @@ void pic16_genPlus (iCode *ic)
                                }
                        }
                        goto release;
+#endif
                }
 
        }
@@ -1056,32 +1173,32 @@ void pic16_genPlus (iCode *ic)
        // TODO:        anything from here to before "release:" is probably obsolete and should be removed
        //              when the regression tests are stable
 
-       if (AOP_SIZE(IC_RESULT(ic)) > AOP_SIZE(IC_RIGHT(ic))) {
-               int sign =  !(SPEC_USIGN(getSpec(operandType(IC_LEFT(ic)))) |
-                               SPEC_USIGN(getSpec(operandType(IC_RIGHT(ic)))) );
+       if (AOP_SIZE(result) > AOP_SIZE(right)) {
+               int sign =  !(SPEC_USIGN(getSpec(operandType(left))) |
+                               SPEC_USIGN(getSpec(operandType(right))) );
 
 
                /* Need to extend result to higher bytes */
-               size = AOP_SIZE(IC_RESULT(ic)) - AOP_SIZE(IC_RIGHT(ic)) - 1;
+               size = AOP_SIZE(result) - AOP_SIZE(right) - 1;
 
                /* First grab the carry from the lower bytes */
-               pic16_emitpcode(POC_CLRF, pic16_popGet(AOP(IC_RESULT(ic)),offset));
-               pic16_emitpcode(POC_RLCF,  pic16_popGet(AOP(IC_RESULT(ic)),offset));
+               pic16_emitpcode(POC_CLRF, pic16_popGet(AOP(result),offset));
+               pic16_emitpcode(POC_RLCF,  pic16_popGet(AOP(result),offset));
 
 
                if(sign) {
                        /* Now this is really horrid. Gotta check the sign of the addends and propogate
                        * to the result */
 
-                       pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(IC_LEFT(ic)),offset-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
-                       pic16_emitpcode(POC_DECF,  pic16_popGet(AOP(IC_RESULT(ic)),offset));
-                       pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(IC_RIGHT(ic)),offset-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
-                       pic16_emitpcode(POC_DECF,  pic16_popGet(AOP(IC_RESULT(ic)),offset));
+                       pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(left),offset-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
+                       pic16_emitpcode(POC_DECF,  pic16_popGet(AOP(result),offset));
+                       pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(right),offset-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
+                       pic16_emitpcode(POC_DECF,  pic16_popGet(AOP(result),offset));
 
                        /* if chars or ints or being signed extended to longs: */
                        if(size) {
                                pic16_emitpcode(POC_MOVLW, pic16_popGetLit(0));
-                               pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(IC_RESULT(ic)),offset,FALSE,FALSE),7,0, PO_GPR_REGISTER));
+                               pic16_emitpcode(POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(result),offset,FALSE,FALSE),7,0, PO_GPR_REGISTER));
                                pic16_emitpcode(POC_MOVLW, pic16_popGetLit(0xff));
                        }
                }
@@ -1090,9 +1207,9 @@ void pic16_genPlus (iCode *ic)
                while(size--) {
       
                        if(sign)
-                               pic16_emitpcode(POC_MOVWF, pic16_popGet(AOP(IC_RESULT(ic)),offset));
+                               pic16_emitpcode(POC_MOVWF, pic16_popGet(AOP(result),offset));
                        else
-                               pic16_emitpcode(POC_CLRF,  pic16_popGet(AOP(IC_RESULT(ic)),offset));
+                               pic16_emitpcode(POC_CLRF,  pic16_popGet(AOP(result),offset));
 
                        offset++;
                }
@@ -1102,9 +1219,9 @@ void pic16_genPlus (iCode *ic)
        //adjustArithmeticResult(ic);
 
        release:
-       pic16_freeAsmop(IC_LEFT(ic),NULL,ic,(RESULTONSTACK(ic) ? FALSE : TRUE));
-       pic16_freeAsmop(IC_RIGHT(ic),NULL,ic,(RESULTONSTACK(ic) ? FALSE : TRUE));
-       pic16_freeAsmop(IC_RESULT(ic),NULL,ic,TRUE);
+       pic16_freeAsmop(left,NULL,ic,(RESULTONSTACK(ic) ? FALSE : TRUE));
+       pic16_freeAsmop(right,NULL,ic,(RESULTONSTACK(ic) ? FALSE : TRUE));
+       pic16_freeAsmop(result,NULL,ic,TRUE);
 }
 
 /*-----------------------------------------------------------------*/
@@ -1138,8 +1255,7 @@ bool pic16_genMinusDec (iCode *ic)
 
       if(size == 2) { 
        pic16_emitpcode(POC_DECF,    pic16_popGet(AOP(IC_RESULT(ic)),LSB));
-       pic16_emitpcode(POC_INCFSZW, pic16_popGet(AOP(IC_RESULT(ic)),LSB));
-       pic16_emitpcode(POC_INCF,    pic16_popGet(AOP(IC_RESULT(ic)),MSB16));
+       emitSKPC;
        pic16_emitpcode(POC_DECF,    pic16_popGet(AOP(IC_RESULT(ic)),MSB16));
 
        pic16_emitcode("decf","%s,f",pic16_aopGet(AOP(IC_RESULT(ic)),LSB,FALSE,FALSE));
@@ -1147,27 +1263,24 @@ bool pic16_genMinusDec (iCode *ic)
        pic16_emitcode(" decf","%s,f",pic16_aopGet(AOP(IC_RESULT(ic)),MSB16,FALSE,FALSE));
       } else {
        /* size is 3 or 4 */
-       pic16_emitpcode(POC_MOVLW,  pic16_popGetLit(0xff));
-       pic16_emitpcode(POC_ADDWF,  pic16_popGet(AOP(IC_RESULT(ic)),LSB));
-       emitSKPNC;
-       pic16_emitpcode(POC_ADDWF,  pic16_popGet(AOP(IC_RESULT(ic)),MSB16));
-       emitSKPNC;
-       pic16_emitpcode(POC_ADDWF,  pic16_popGet(AOP(IC_RESULT(ic)),MSB24));
+       pic16_emitpcode(POC_DECF,   pic16_popGet(AOP(IC_RESULT(ic)),LSB));
+       pic16_emitpcode(POC_CLRF,   pic16_popCopyReg(&pic16_pc_wreg));
+       pic16_emitpcode(POC_SUBWFB_D1,   pic16_popGet(AOP(IC_RESULT(ic)),MSB16));
+       pic16_emitpcode(POC_SUBWFB_D1,   pic16_popGet(AOP(IC_RESULT(ic)),MSB24));
 
        pic16_emitcode("movlw","0xff");
        pic16_emitcode("addwf","%s,f",pic16_aopGet(AOP(IC_RESULT(ic)),LSB,FALSE,FALSE));
 
-       emitSKPNC;
+       //emitSKPNC;
        pic16_emitcode("addwf","%s,f",pic16_aopGet(AOP(IC_RESULT(ic)),MSB16,FALSE,FALSE));
-       emitSKPNC;
+       //emitSKPNC;
        pic16_emitcode("addwf","%s,f",pic16_aopGet(AOP(IC_RESULT(ic)),MSB24,FALSE,FALSE));
 
        if(size > 3) {
-         emitSKPNC;
-         pic16_emitpcode(POC_ADDWF,  pic16_popGet(AOP(IC_RESULT(ic)),MSB32));
+         pic16_emitpcode(POC_SUBWFB_D1,   pic16_popGet(AOP(IC_RESULT(ic)),MSB32));
 
          pic16_emitcode("skpnc","");
-         emitSKPNC;
+         //emitSKPNC;
          pic16_emitcode("addwf","%s,f",pic16_aopGet(AOP(IC_RESULT(ic)),MSB32,FALSE,FALSE));
        }
 
@@ -1524,13 +1637,32 @@ void pic16_genMinus (iCode *ic)
     size--;
 
     while(size--){
-      if (pic16_sameRegs(AOP(IC_LEFT(ic)), AOP(IC_RESULT(ic)))) {
+      if (offset < AOP_SIZE(IC_RIGHT(ic)))
        pic16_mov2w(AOP(IC_RIGHT(ic)),offset);
-       pic16_emitpcode(POC_SUBWFB_D1,  pic16_popGet(AOP(IC_RESULT(ic)),offset));
+      else {
+       pic16_emitpcode (POC_CLRF, pic16_popCopyReg (&pic16_pc_wreg));
+       if (!SPEC_USIGN(operandType(IC_RIGHT(ic)))) {
+         // signed -- sign extend the right operand
+         pic16_emitpcode (POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(IC_RIGHT(ic)),AOP_SIZE(IC_RIGHT(ic))-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
+         pic16_emitpcode (POC_COMF, pic16_popCopyReg (&pic16_pc_wreg));
+       }
+      }
+      if (pic16_sameRegs(AOP(IC_LEFT(ic)), AOP(IC_RESULT(ic)))) {
+       pic16_emitpcode(POC_SUBWFB_D1, pic16_popGet(AOP(IC_RESULT(ic)),offset));
       } else {
-       pic16_mov2w(AOP(IC_RIGHT(ic)),offset);
-       pic16_emitpcode(POC_SUBWFB_D0,  pic16_popGet(AOP(IC_LEFT(ic)),offset));
-       pic16_emitpcode(POC_MOVWF,  pic16_popGet(AOP(IC_RESULT(ic)),offset));
+       if (offset < AOP_SIZE(IC_LEFT(ic))) {
+         pic16_emitpcode(POC_SUBWFB_D0,  pic16_popGet(AOP(IC_LEFT(ic)),offset));
+         pic16_emitpcode(POC_MOVWF,  pic16_popGet(AOP(IC_RESULT(ic)),offset));
+       } else {
+         // zero extend the left operand
+         pic16_emitpcode (POC_CLRF, pic16_popGet(AOP(IC_RESULT(ic)), offset));
+         if (!SPEC_USIGN(operandType(IC_LEFT(ic)))) {
+           // signed -- sign extend the left operand
+           pic16_emitpcode (POC_BTFSC, pic16_newpCodeOpBit(pic16_aopGet(AOP(IC_LEFT(ic)),AOP_SIZE(IC_LEFT(ic))-1,FALSE,FALSE),7,0, PO_GPR_REGISTER));
+           pic16_emitpcode (POC_COMF, pic16_popGet(AOP(IC_RESULT(ic)), offset)); // keep CARRY/#BORROW bit intact!
+         }
+         pic16_emitpcode(POC_SUBWFB_D1, pic16_popGet(AOP(IC_RESULT(ic)),offset));
+       }
       }        
       offset++;
     }