Added _SUB, _MUL, _DIV

strzelca · Jan 4, 2024 · 3182c7b · 3182c7b
1 parent 3f28c08
commit 3182c7b
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Showing 4 changed files with 130 additions and 8 deletions.
diff --git a/lib/cpu.c b/lib/cpu.c
@@ -25,8 +25,8 @@ void destroy_cpu(cpu_t *cpu) {
 
 void print_cpu_status(const cpu_t *cpu) {
     printf("CPU STATUS\n");
-    printf("A  -> 0x%04x\n", cpu->A);
-    printf("B  -> 0x%04x\n", cpu->B);
+    printf("A  -> 0x%04x (%hi)\n", cpu->A, cpu->A);
+    printf("B  -> 0x%04x (%d)\n", cpu->B, cpu->B);
     printf("PC -> 0x%04x\n", cpu->PC);
     printf("FLAGS -> 0x%08x\n", cpu->flags.flags);
 }
@@ -157,6 +157,84 @@ void fde(cpu_t *cpu, const mem_t *mem) {
             }
             _SUB(R1, R2, R3, (uint32_t*) &cpu->flags);
         break;
+        case MUL:
+            // reg, v1, v2
+            switch (mem->mem[cpu->PC++]) {
+                case REGA:
+                    R1 = &cpu->A;
+                break;
+                case REGB:
+                    R1 = &cpu->B;
+                break;
+                default:
+                    illegal_instruction(cpu, mem);
+                break;
+            }
+            switch (mem->mem[cpu->PC++]) {
+                case REGA:
+                    R2 = &cpu->A;
+                break;
+                case REGB:
+                    R2 = &cpu->B;
+                break;
+                default:
+                    V1 = mem->mem[cpu->PC-1];
+                    R2 = &V1;
+                break;
+            }
+            switch (mem->mem[cpu->PC++]) {
+                case REGA:
+                    R3 = &cpu->A;
+                break;
+                case REGB:
+                    R3 = &cpu->B;
+                break;
+                default:
+                    V2 = mem->mem[cpu->PC-1];
+                    R3 = &V2;
+                break;
+            }
+            _MUL(R1, R2, R3, (uint32_t*) &cpu->flags);
+        break;
+        case DIV:
+            // reg, v1, v2
+            switch (mem->mem[cpu->PC++]) {
+                case REGA:
+                    R1 = &cpu->A;
+                break;
+                case REGB:
+                    R1 = &cpu->B;
+                break;
+                default:
+                    illegal_instruction(cpu, mem);
+                break;
+            }
+            switch (mem->mem[cpu->PC++]) {
+                case REGA:
+                    R2 = &cpu->A;
+                break;
+                case REGB:
+                    R2 = &cpu->B;
+                break;
+                default:
+                    V1 = mem->mem[cpu->PC-1];
+                    R2 = &V1;
+                break;
+            }
+            switch (mem->mem[cpu->PC++]) {
+                case REGA:
+                    R3 = &cpu->A;
+                break;
+                case REGB:
+                    R3 = &cpu->B;
+                break;
+                default:
+                    V2 = mem->mem[cpu->PC-1];
+                    R3 = &V2;
+                break;
+            }
+            _DIV(R1, R2, R3, (uint32_t*) &cpu->flags);
+        break;
         case NUL:
             illegal_instruction(cpu, mem);
             break;

diff --git a/lib/isa.c b/lib/isa.c
@@ -12,6 +12,7 @@ void _MOV(uint16_t* dst, const uint16_t _n) {
 }
 
 void _ADD(uint16_t* dst, const uint16_t *v1, const uint16_t *v2, uint32_t *flags) {
+    uint16_t _v1 = *v1;
     *flags = 0;
     *flags = *v1 & *v2;
     *dst = *v1 ^ *v2;
@@ -23,15 +24,46 @@ void _ADD(uint16_t* dst, const uint16_t *v1, const uint16_t *v2, uint32_t *flags
         *dst = *dst ^ carry;
     }
 
-    if (*dst <= *v2 && ~*v2 < *v2 ) *flags ^= 1 << 0x8;
-
+    // detect overflow
+    if(*dst > 0 && *dst < 0x7FFF && _v1 > 0x7FFF) *flags ^= 1 << 0x8;
     if (*dst >> 15 == 1) *flags ^= 1 << 0x10;
-
     if (*dst == 0) *flags ^= 1 << 0x18;
 
 }
 
+void _INC(uint16_t* dst, uint32_t *flags) {
+    uint16_t _d = *dst;
+    *flags = 0;
+    *flags = *dst & 1;
+    *dst = *dst ^ 1;
+
+
+    while (*flags != 0){
+        uint32_t carry = *flags << 1;
+        *flags = *dst & carry;
+        *dst = *dst ^ carry;
+    }
+
+    if (*dst > 0 && *dst < 0x7FFF && _d > 0x7FFF) *flags ^= 1 << 0x8;
+    if (*dst >> 15) *flags ^= 1 << 0x10;
+    if (!*dst) *flags ^= 1 << 0x18;
+}
+
 void _SUB(uint16_t* dst, const uint16_t *v1, uint16_t *v2, uint32_t *flags) {
-    *v2 = ~*v2 + 1;
-    _ADD(dst, v1, v2, flags);
+    uint16_t _v2 = ~*v2 + 1;
+    _ADD(dst, v1, &_v2, flags);
+}
+
+void _MUL(uint16_t* dst, const uint16_t *v1, uint16_t *v2, uint32_t *flags) {
+    while((*v2)--) _ADD(dst, dst, v1, flags);
+}
+
+void _DIV(uint16_t* dst, uint16_t *v1, uint16_t *v2, uint32_t *flags) {
+    uint32_t _save_flags;
+    while(*v1 > 0 || ((*flags >> 0x10) & 0x001) == 1 && (*flags >> 0x18) == 1) {
+        _SUB(v1, v1, v2, flags);
+        _save_flags = *flags;
+        _INC(dst, flags);
+        *flags = _save_flags;
+    }
 }
diff --git a/lib/isa.h b/lib/isa.h
@@ -13,6 +13,8 @@
 #define MOV 0x0001
 #define ADD 0x0002
 #define SUB 0x0003
+#define MUL 0x0004
+#define DIV 0x0005
 
 #define HLT 0xFAFB
 #define NUL 0x0000
@@ -21,6 +23,9 @@
 void _MOV(uint16_t* dst, uint16_t _n);
 void _ADD(uint16_t* dst, const uint16_t *v1, const uint16_t *v2, uint32_t *flags);
 void _SUB(uint16_t* dst, const uint16_t *v1, uint16_t *v2, uint32_t *flags);
+void _MUL(uint16_t* dst, const uint16_t *v1, uint16_t *v2, uint32_t *flags);
+void _DIV(uint16_t* dst, uint16_t *v1, uint16_t *v2, uint32_t *flags);
+
 
 
 #endif //ISA_H
diff --git a/main.c b/main.c
@@ -2,14 +2,21 @@
 
 #include "lib/logicb.h"
 #include "lib/cpu.h"
+#include "lib/isa.h"
 
 int main() {
     logic_b_t *logicb = new_logicb();
 
     print_logicb(logicb);
 
 
-    const uint16_t prog[] = {0x0001, 0xAFFF, 0x0008, 0x0002, 0xBFFF, 0xAFFF, 0x0008, 0x0003, 0xAFFF, 0xAFFF, 0x0009, 0x0002, 0xAFFF, 0xAFFF, 0x0001, 0xFAFB};
+    const uint16_t prog[] = {
+        ADD, REGA, REGA, 0x0008, 
+        DIV, REGB, REGA, 0x0004, 
+        SUB, REGA, REGA, 0x0004, 
+        ADD, REGA, REGA, 0x0008,
+        0xFAFB
+    };
 
     memcpy(logicb->mem->mem, prog, sizeof(prog));