a5: Lessbarkeit mit ein paar #defines etc. verbessert

CMakeLists.txt

@@ -10,5 +10,4 @@ set (LIBRARY_OUTPUT_PATH ${EXECUTABLE_OUTPUT_PATH})
 
 add_subdirectory(src/c/a3)
 
-
 add_custom_target(a5 COMMAND make WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/src/c/a5)

src/c/a5/Makefile

@@ -1,15 +1,12 @@
-# C-Quellcode kompilieren und mit ASM-Modul linken
 flagtest: addsub.o flagtest.o
 	gcc -m32 -o flagtest flagtest.o addsub.o -Wall -Wextra 	# linken
 
 flagtest.o: flagtest.c
 	gcc -m32 -c -o flagtest.o flagtest.c -Wall -Wextra	# compilieren
 
-# ASM-Modul assemblieren
 addsub.o: addsub.asm
 	nasm -f elf -o addsub.o addsub.asm # assemblieren
 
-# Projekt aufraemen 
 clean:
 	@echo 'Ausgabedateien loeschen'
 	rm -f flagtest *.o *~

src/c/a5/addsub.asm

@@ -1,6 +1,12 @@
 
 section .text
 
+op1 equ 8
+op2 equ 12
+what equ 16
+flag equ 20
+plus equ 0x2b;hex code for + symbol
+
 global addsub
 
 addsub:
@@ -12,16 +18,16 @@ addsub:
 
     mov eax, 0
 
-    mov ax, word [ebp+8] ;op1
-    mov bx, word [ebp+16] ;what
+    mov ax, word [ebp+op1]
+    mov bx, word [ebp+what]
 
-    cmp bx, 0x2b;hex code for + symbol
+    cmp bx, plus
     jne substract
 
-    add ax, word [ebp+12] ;op2
+    add ax, word [ebp+op2]
     jmp return
 
-substract: sub ax, word [ebp+12] ;op2
+substract: sub ax, word [ebp+op2]
 
 return:
 
@@ -29,7 +35,7 @@ return:
 
     pop edx;write flags to edx
 
-    mov ebx, [ebp+20];write flag pointer address to ebx
+    mov ebx, [ebp+flag];write flag pointer address to ebx
 
     mov [ebx], edx;write flags to pointer address
 

src/c/a5/flagtest.c

@@ -1,6 +1,26 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+/*
+     * 0: Overflow flag
+     * 1: Direction flag
+     * 2: Interrupt enable flag
+     * 3: Trap flag
+     * 4: Signed flag
+     * 5: Zero flag
+     * 6: reserved
+     * 7: Auxiliary flag
+     * 8: reserved
+     * 9: Parity flag
+     * 10: reserved
+     * 11: Carry flag
+     */
+
+#define flags_length 12
+#define flag_overflow 0
+#define flag_carry 11
+
+
 /**
  * @param op1 ebp+8
  * @param op2 ebp+12
@@ -15,15 +35,16 @@ int main(int argc, char **argv) {
         printf("Wrong number of arguments\n");
         return -1;
     }
-    if (*argv[2] != '+' && *argv[2] != '-') {
+
+    char what = *argv[2];
+
+    if (what != '+' && what != '-') {
         printf("Only the operators +/- are supported\n");
         return -1;
     }
 
-
     int op1 = atoi(argv[1]);
     int op2 = atoi(argv[3]);
-    char what = *argv[2];
 
 
     //we need the operators both as signed and unsigned
@@ -44,43 +65,26 @@ int main(int argc, char **argv) {
     printf("Flags:\n");
     printf("O D I T S Z   A   P   C\n");
 
-
-    /*
-     * 0: Overflow flag
-     * 1: Direction flag
-     * 2: Interrupt enable flag
-     * 3: Trap flag
-     * 4: Signed flag
-     * 5: Zero flag
-     * 6: reserved
-     * 7: Auxiliary flag
-     * 8: reserved
-     * 9: Parity flag
-     * 10: reserved
-     * 11: Carry flag
-     */
-    int flagArray[12];
+    int flagArray[flags_length];
 
 
     //flags are saved as a decimal value, so we need to convert to binary
-    for(int i = 0; i < 12; ++i) {
+    for (int i = 0; i < flags_length; ++i) {
         flagArray[i] = *flags % 2;
         *flags = *flags / 2;
     }
 
-    for(int i = 12; i > 0; --i) {
-        printf("%d ", flagArray[i-1]);
+    for (int i = flags_length; i > 0; --i) {
+        printf("%d ", flagArray[i - 1]);
     }
 
+
     printf("\n\n");
 
     printf("Ergebnis und Operanden Signed:\n");
     printf("%d %c %d = %d\t", sop1, what, sop2, signedRes);
 
-    if(flagArray[0] == 0)
-        printf("Ergebnis ist richtig!");
-    else
-        printf("Ergebnis ist falsch!");
+    printf(flagArray[flag_overflow] == 0 ? "Ergebnis ist richtig!" : "Ergebnis ist falsch!");
 
 
     printf("\n\n");
@@ -89,10 +93,8 @@ int main(int argc, char **argv) {
     printf("Ergebnis und Operanden Unsigned:\n");
     printf("%u %c %u = %u\t", uop1, what, uop2, unsignedRes);
 
-    if(flagArray[11] == 0)
-        printf("Ergebnis ist richtig!");
-    else
-        printf("Ergebnis ist falsch!");
+
+    printf(flagArray[flag_carry] == 0 ? "Ergebnis ist richtig!" : "Ergebnis ist falsch!");
 
 
     printf("\n\n");