Merge ADD and ADDC operations into common function

diff --git a/src/common/Makefile.am b/src/common/Makefile.am
index ba295d9..aa19efe 100644 (file)
--- a/src/common/Makefile.am
+++ b/src/common/Makefile.am
@@ -15,6 +15,7 @@ libemu8051_a_SOURCES = \
        memory.c memory.h \
        psw.c psw.h \
        sfr.c sfr.h \
+       operations.c operations.h \
        timers.c timers.h \
        common.h \
        reg8051.h

diff --git a/src/common/opcode2c.pl b/src/common/opcode2c.pl
index df8b04e..1030b56 100755 (executable)
--- a/src/common/opcode2c.pl
+++ b/src/common/opcode2c.pl
@@ -68,6 +68,7 @@ print INST_IMP "#include \"reg8051.h\"\n";
 print INST_IMP "#include \"cpu8051.h\"\n";
 print INST_IMP "#include \"memory.h\"\n";
 print INST_IMP "#include \"psw.h\"\n";
+print INST_IMP "#include \"operations.h\"\n";
 print INST_IMP "#include \"instructions_8051.h\"\n\n\n";
 
 # Header for disasm.h
@@ -444,27 +445,7 @@ for ($i=0 ; $i< 256; $i++) {
 
        # ADD
        if ($insttype[$i] == 13) {
-           cfw("psw_clr_cy();");
-           cfw("psw_clr_ac();");
-           cfw("psw_clr_ov();");
-            # The Overflow (OV) bit is set if there is a carry-out of bit 6 or
-            # out of bit 7, but not both. In other words, if the addition of the
-            # Accumulator, operand and (in the case of ADDC) the Carry flag
-            # treated as signed values results in a value that is out of the
-            # range of a signed byte (-128 through +127) the Overflow flag is
-            # set. Otherwise, the Overflow flag is cleared.
-           cfw("if ( destination + source > 0xFF ) {");
-            # Carry from bit 7
-           cfw("   psw_set_cy();");
-            # If no carry from bit 6, set OV
-           cfw("   if (((destination & 0x7F) + (source & 0x7F)) < 0x80)");
-           cfw("       psw_set_ov();");
-            # If no carry from bit 7, but caary from bit 6, set OV
-           cfw("} else if (((destination & 0x7F) + (source & 0x7F)) > 0x7F )");
-           cfw("   psw_set_ov();");
-           cfw("if (((destination & 0x0F) + (source & 0x0F)) > 0x0F)");
-           cfw("   psw_set_ac();");
-           cfw("destination += source;");
+           cfw("destination = addition(destination, source, 0);");
        }
 
        # JNB
@@ -491,18 +472,7 @@ for ($i=0 ; $i< 256; $i++) {
         # add the Carry flag to the result.
        if ($insttype[$i] == 17) {
            cfw("unsigned char carryflag = psw_read_cy();");
-           cfw("psw_clr_cy();");
-           cfw("psw_clr_ac();");
-           cfw("psw_clr_ov();");
-           cfw("if ( destination + source + carryflag > 0xFF ) {");
-           cfw("   psw_set_cy();");
-           cfw("   if (((destination & 0x7F) + (source & 0x7F) + carryflag) < 0x80)");
-           cfw("       psw_set_ov();");
-           cfw("} else if (((destination & 0x7F) + (source & 0x7F) + carryflag) > 0x7F)");
-           cfw("   psw_set_ov();");
-           cfw("if (((destination & 0x0F) + (source & 0x0F) + carryflag) > 0x0F)");
-           cfw("   psw_set_ac();");
-           cfw("destination += source + carryflag;");
+           cfw("destination = addition(destination, source, carryflag);");
        }
 
        # JC

diff --git a/src/common/operations.c b/src/common/operations.c
new file mode 100644 (file)
index 0000000..a454712
--- /dev/null
+++ b/src/common/operations.c
@@ -0,0 +1,68 @@
+/*
+ * operations.c
+ *
+ * Copyright (C) 2014 Hugo Villeneuve <hugo@hugovil.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#if HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "common.h"
+#include "reg8051.h"
+#include "cpu8051.h"
+#include "sfr.h"
+#include "psw.h"
+#include "memory.h"
+#include "operations.h"
+
+/*
+ * ADD and ADDC function identically except that ADDC adds the value of operand
+ * as well as the value of the Carry flag whereas ADD does not add the Carry
+ * flag to the result.
+ */
+int
+addition(int dst, int src, int carry)
+{
+       psw_clr_cy();
+       psw_clr_ac();
+       psw_clr_ov();
+
+       /*
+        * The Overflow (OV) bit is set if there is a carry-out of bit 6 or
+        * out of bit 7, but not both. In other words, if the addition of the
+        * Accumulator, operand and (in the case of ADDC) the Carry flag
+        * treated as signed values results in a value that is out of the
+        * range of a signed byte (-128 through +127) the Overflow flag is
+        * set. Otherwise, the Overflow flag is cleared.
+        */
+       if (dst + src + carry > 0xFF) {
+               /* Carry from bit 7. */
+               psw_set_cy();
+
+               if (((dst & 0x7F) + (src & 0x7F) + carry) < 0x80)
+                       psw_set_ov(); /* If no carry from bit 6, set OV. */
+       } else if (((dst & 0x7F) + (src & 0x7F) + carry) > 0x7F) {
+               /* If no carry from bit 7, but carry from bit 6, set OV. */
+               psw_set_ov();
+       }
+
+       if (((dst & 0x0F) + (src & 0x0F) + carry) > 0x0F)
+               psw_set_ac();
+
+       return dst + src + carry;
+}

diff --git a/src/common/operations.h b/src/common/operations.h
new file mode 100644 (file)
index 0000000..a7533ab
--- /dev/null
+++ b/src/common/operations.h
@@ -0,0 +1,27 @@
+/*
+ * operations.h
+ *
+ * Copyright (C) 2014 Hugo Villeneuve <hugo@hugovil.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef OPERATIONS_H
+#define OPERATIONS_H 1
+
+int
+addition(int dest, int src, int carry);
+
+#endif /* OPERATIONS_H */