* src/mcs51/gen.c (genMinus): fixed bug 1270906: reverse subtraction, carry must...

[fw/sdcc] / src / mcs51 / gen.c

diff --git a/src/mcs51/gen.c b/src/mcs51/gen.c
index 7ae3fa4edbb9078cf84aa7c4cdb2ef5e83cadb0d..0757d80dcbd284ecb38568a82fb079b03d7eaf10 100644 (file)
--- a/src/mcs51/gen.c
+++ b/src/mcs51/gen.c
@@ -1803,7 +1803,6 @@ genCpl (iCode * ic)
              bit -> int -> ~int -> bit
              uchar -> int -> ~int -> bit
           */
-          werror(W_COMPLEMENT);
           emitcode ("setb", "%s", IC_RESULT (ic)->aop->aopu.aop_dir);
           goto release;
         }
@@ -4314,7 +4313,7 @@ release:
 }
 
 /*-----------------------------------------------------------------*/
-/* genMinusDec :- does subtraction with deccrement if possible     */
+/* genMinusDec :- does subtraction with decrement if possible      */
 /*-----------------------------------------------------------------*/
 static bool
 genMinusDec (iCode * ic)
@@ -4527,22 +4526,35 @@ genMinus (iCode * ic)
 
       while (size--)
         {
-          if (useCarry || ((lit >> (offset * 8)) & 0x0FFL)) {
+          if (useCarry || ((lit >> (offset * 8)) & 0x0FFL))
+            {
             MOVA (aopGet (IC_LEFT (ic), offset, FALSE, FALSE));
-            if (!offset && !size && lit== (unsigned long) -1) {
-              emitcode ("dec", "a");
-            } else if (!useCarry) {
-              /* first add without previous c */
-              emitcode ("add", "a,#0x%02x",
-                        (unsigned int) ((lit >> (offset * 8)) & 0x0FFL));
-              useCarry = TRUE;
-            } else {
-              emitcode ("addc", "a,#0x%02x",
-                        (unsigned int) ((lit >> (offset * 8)) & 0x0FFL));
+              if (!offset && !size && lit== (unsigned long) -1)
+                {
+                  emitcode ("dec", "a");
+                }
+              else if (!useCarry)
+                {
+                  /* first add without previous c */
+                  emitcode ("add", "a,#0x%02x",
+                            (unsigned int) ((lit >> (offset * 8)) & 0x0FFL));
+                  useCarry = TRUE;
+                }
+              else
+                {
+                  emitcode ("addc", "a,#0x%02x",
+                            (unsigned int) ((lit >> (offset * 8)) & 0x0FFL));
+                }
+              aopPut (IC_RESULT (ic), "a", offset++, isOperandVolatile (IC_RESULT (ic), FALSE));
             }
-            aopPut (IC_RESULT (ic), "a", offset++, isOperandVolatile (IC_RESULT (ic), FALSE));
-            } else {
+          else
+            {
               /* no need to add zeroes */
+              if (!sameRegs (AOP (IC_RESULT (ic)), AOP (IC_LEFT (ic))))
+                {
+                  aopPut (IC_RESULT (ic), aopGet (IC_LEFT (ic), offset, FALSE, FALSE),
+                          offset, isOperandVolatile (IC_RESULT (ic), FALSE));
+                }
               offset++;
             }
         }
@@ -4569,13 +4581,17 @@ genMinus (iCode * ic)
               emitcode ("subb", "a,b");
               popB (pushedB);
             } else {
+              /* reverse subtraction with 2's complement */
+              if (offset == 0)
+                emitcode( "setb", "c");
+               else
+                emitcode( "cpl", "c");
               wassertl(!aopGetUsesAcc(leftOp, offset), "accumulator clash");
               MOVA (aopGet(rightOp, offset, FALSE, TRUE));
-              if (offset == 0) {
-                emitcode( "setb", "c");
-              }
               emitcode("subb", "a,%s", aopGet(leftOp, offset, FALSE, TRUE));
               emitcode("cpl", "a");
+              if (size) /* skip if last byte */
+                emitcode( "cpl", "c");
             }
           } else {
             MOVA (aopGet (leftOp, offset, FALSE, FALSE));
@@ -7284,6 +7300,140 @@ genGetHbit (iCode * ic)
   freeAsmop (result, NULL, ic, TRUE);
 }
 
+/*-----------------------------------------------------------------*/
+/* genGetAbit - generates code get a single bit                    */
+/*-----------------------------------------------------------------*/
+static void
+genGetAbit (iCode * ic)
+{
+  operand *left, *right, *result;
+  int shCount;
+
+  D(emitcode (";     genGetAbit",""));
+
+  left = IC_LEFT (ic);
+  right = IC_RIGHT (ic);
+  result = IC_RESULT (ic);
+  aopOp (left, ic, FALSE);
+  aopOp (right, ic, FALSE);
+  aopOp (result, ic, FALSE);
+
+  shCount = (int) floatFromVal (AOP (IC_RIGHT (ic))->aopu.aop_lit);
+
+  /* get the needed byte into a */
+  MOVA (aopGet (left, shCount / 8, FALSE, FALSE));
+  shCount %= 8;
+  if (AOP_TYPE (result) == AOP_CRY)
+    {
+      if ((shCount) == 7)
+          emitcode ("rlc", "a");
+      else if ((shCount) == 0)
+          emitcode ("rrc", "a");
+      else
+          emitcode ("mov", "c,acc[%d]", shCount);
+      outBitC (result);
+    }
+  else
+    {
+      switch (shCount)
+        {
+        case 2:
+          emitcode ("rr", "a");
+          //fallthrough
+        case 1:
+          emitcode ("rr", "a");
+          //fallthrough
+        case 0:
+          emitcode ("anl", "a,#0x01");
+          break;
+        case 3:
+        case 5:
+          emitcode ("mov", "c,acc[%d]", shCount);
+          emitcode ("clr", "a");
+          emitcode ("rlc", "a");
+          break;
+        case 4:
+          emitcode ("swap", "a");
+          emitcode ("anl", "a,#0x01");
+          break;
+        case 6:
+          emitcode ("rl", "a");
+          //fallthrough
+        case 7:
+          emitcode ("rl", "a");
+          emitcode ("anl", "a,#0x01");
+          break;
+        }
+      outAcc (result);
+    }
+
+  freeAsmop (left, NULL, ic, TRUE);
+  freeAsmop (right, NULL, ic, TRUE);
+  freeAsmop (result, NULL, ic, TRUE);
+}
+
+/*-----------------------------------------------------------------*/
+/* genGetByte - generates code get a single byte                   */
+/*-----------------------------------------------------------------*/
+static void
+genGetByte (iCode * ic)
+{
+  operand *left, *right, *result;
+  int offset;
+
+  D(emitcode (";     genGetByte",""));
+
+  left = IC_LEFT (ic);
+  right = IC_RIGHT (ic);
+  result = IC_RESULT (ic);
+  aopOp (left, ic, FALSE);
+  aopOp (right, ic, FALSE);
+  aopOp (result, ic, FALSE);
+
+  offset = (int)floatFromVal (AOP (right)->aopu.aop_lit) / 8;
+  aopPut (result,
+          aopGet (left, offset, FALSE, FALSE),
+          0,
+          isOperandVolatile (result, FALSE));
+
+  freeAsmop (left, NULL, ic, TRUE);
+  freeAsmop (right, NULL, ic, TRUE);
+  freeAsmop (result, NULL, ic, TRUE);
+}
+
+/*-----------------------------------------------------------------*/
+/* genGetWord - generates code get two bytes                       */
+/*-----------------------------------------------------------------*/
+static void
+genGetWord (iCode * ic)
+{
+  operand *left, *right, *result;
+  int offset;
+
+  D(emitcode (";     genGetWord",""));
+
+  left = IC_LEFT (ic);
+  right = IC_RIGHT (ic);
+  result = IC_RESULT (ic);
+  aopOp (left, ic, FALSE);
+  aopOp (right, ic, FALSE);
+  aopOp (result, ic, FALSE);
+
+  offset = (int)floatFromVal (AOP (right)->aopu.aop_lit) / 8;
+  aopPut (result,
+          aopGet (left, offset, FALSE, FALSE),
+          0,
+          isOperandVolatile (result, FALSE));
+  aopPut (result,
+          aopGet (left, offset+1, FALSE, FALSE),
+          1,
+          isOperandVolatile (result, FALSE));
+
+  freeAsmop (left, NULL, ic, TRUE);
+  freeAsmop (right, NULL, ic, TRUE);
+  freeAsmop (result, NULL, ic, TRUE);
+}
+
 /*-----------------------------------------------------------------*/
 /* genSwap - generates code to swap nibbles or bytes               */
 /*-----------------------------------------------------------------*/
@@ -11129,6 +11279,18 @@ gen51Code (iCode * lic)
           genGetHbit (ic);
           break;
 
+        case GETABIT:
+          genGetAbit (ic);
+          break;
+
+        case GETBYTE:
+          genGetByte (ic);
+          break;
+
+        case GETWORD:
+          genGetWord (ic);
+          break;
+
         case LEFT_OP:
           genLeftShift (ic);
           break;