quick-n-dirty num to str

src/vm.c

@@ -7,7 +7,7 @@
 #include <unistd.h>
 
 /* #define MEMORY_SIZE 65536 /\* 64KB memory (adjustable) *\/ */
-#define MEMORY_SIZE 200 
+#define MEMORY_SIZE 1024
 typedef union {
   float f;
   uint32_t u;
@@ -27,16 +27,66 @@ typedef enum {
   OP_MOV,           /* dest = src1	     */
   OP_JMP,           /* jump to address src1 unconditionally */
   OP_JGZ,           /* jump to address dest if src1 > 0 */
+  OP_INT_TO_STRING, /* dest = src1 as str */
+  OP_F32_TO_STRING, /* dest = src2 as str */
   OP_READ_STRING,
   OP_PRINT_STRING,
 } Opcode;
 
+int core_dump() {
+  FILE *file = fopen("memory_dump.bin", "wb");
+  if (!file) {
+    perror("Failed to open file");
+    return EXIT_FAILURE;
+  }
+  size_t written = fwrite(memory, 1, MEMORY_SIZE, file);
+  if (written != MEMORY_SIZE) {
+    fprintf(stderr, "Incomplete write: %zu bytes written out of %u\n", written,
+            MEMORY_SIZE);
+    fclose(file);
+    return EXIT_FAILURE;
+  }
+
+  fclose(file);
+  return EXIT_SUCCESS;
+}
+
 uint8_t get_char(uint32_t word, int index) {
-  return (word >> (8 * index)) & 0xFF;
+  return (word >> (8 * (3 - index))) & 0xFF;
 }
 
 uint32_t set_char(uint32_t word, int index, uint8_t ch) {
-  return (word & ~(0xFF << (8 * index))) | (ch << (8 * index));
+  return (word & ~(0xFF << (8 * (3 - index)))) | (ch << (8 * (3 - index)));
+}
+
+/* Pack string into union-based memory */
+void pack_string(const char *str, uint32_t length, uint32_t dest_addr) {
+  memory[dest_addr].u = length;
+  uint32_t buffer_addr = dest_addr + 1;
+  int word_index = 0;
+  int char_index = 0;
+
+  uint32_t i = 0;
+  while (i < length) {
+    char ch = str[i++];
+    if (ch == '\0' || ch == EOF) {
+      uint32_t word = memory[buffer_addr + word_index].u;
+      word = set_char(word, char_index, '\0');
+      memory[buffer_addr + word_index].u = word;
+      break;
+    }
+
+    uint32_t word = memory[buffer_addr + word_index].u;
+    word = set_char(word, char_index, ch);
+    memory[buffer_addr + word_index].u = word;
+
+    char_index++;
+    if (char_index == 4) {
+      char_index = 0;
+      word_index++;
+    }
+    length++;
+  }
 }
 
 void run_vm() {
@@ -109,22 +159,32 @@ void run_vm() {
       pc = (jump_target & mask) | (pc & ~mask);
       break;
     }
+    case OP_INT_TO_STRING: {
+      int32_t a = (int32_t)memory[src1_addr].u;
+      char buffer[32];
+      sprintf(buffer, "%d", a);
+      pack_string(buffer, strlen(buffer), dest_addr);
+      break;
+    }
+    case OP_F32_TO_STRING: {
+      float a = memory[src1_addr].f;
+      char buffer[32];
+      sprintf(buffer, "%f", a);
+      pack_string(buffer, strlen(buffer), dest_addr);
+      break;
+    }
     case OP_PRINT_STRING: {
       uint32_t string_addr = src1_addr;
-      uint32_t length = memory[src1_addr-1].u;
+      uint32_t length = memory[src1_addr - 1].u;
-
       uint32_t i;
-      while (i < length) {
+      for (i = 0; i < length;) {
-        int j = 0;
+        uint32_t word = memory[string_addr + (i / 4)].u;
-        uint32_t word = memory[string_addr + (i++)].u;
+        uint8_t ch = get_char(word, i % 4);
-        for (j = 0; j < 4; j++) {
-          char ch = (word >> (8 * j)) & 0xFF;
         if (ch == '\0')
-            goto done;
+          break;
         putchar(ch);
+        i++;
       }
-      }
-    done:
       putchar('\n');
       break;
     }
@@ -132,31 +192,30 @@ void run_vm() {
       putchar('>');
       putchar(' ');
       uint32_t buffer_addr = dest_addr + 1;
+      uint32_t length = 0;
       int word_index = 0;
       int char_index = 0;
-      uint32_t length = 1;
 
       while (1) {
         int ch = getchar();
         if (ch == '\n' || ch == EOF) {
-          /* Store null terminator */
           uint32_t word = memory[buffer_addr + word_index].u;
           word = set_char(word, char_index, '\0');
           memory[buffer_addr + word_index].u = word;
           break;
         }
+
         uint32_t word = memory[buffer_addr + word_index].u;
         word = set_char(word, char_index, ch);
         memory[buffer_addr + word_index].u = word;
-        length++;
 
         char_index++;
         if (char_index == 4) {
           char_index = 0;
           word_index++;
         }
+        length++;
       }
-
       memory[dest_addr].u = length;
       break;
     }
@@ -168,27 +227,28 @@ void run_vm() {
 }
 
 int main() {
-  memory[0].u = OP_READ_STRING;
+  int i = 0;
-  memory[1].u = 0;
+  memory[i++].u = OP_ADD_F32;
-  memory[2].u = 0;
+  memory[i++].u = 102;
-  memory[3].u = 104;
+  memory[i++].u = 103;
-  memory[4].u = OP_ADD_F32;
+  memory[i++].u = 103;
-  memory[5].u = 102;
+  memory[i++].u = OP_SUB;
-  memory[6].u = 103;
+  memory[i++].u = 100;
-  memory[7].u = 103;
+  memory[i++].u = 101;
-  memory[8].u = OP_SUB;
+  memory[i++].u = 100;
-  memory[9].u = 100;
+  memory[i++].u = OP_JGZ;
-  memory[10].u = 101;
+  memory[i++].u = 100;
-  memory[11].u = 100;
+  memory[i++].u = 4;
-  memory[12].u = OP_JGZ;
+  memory[i++].u = 4;
-  memory[13].u = 100;
+  memory[i++].u = OP_F32_TO_STRING;
-  memory[14].u = 4;
+  memory[i++].u = 103;
-  memory[15].u = 4;
+  memory[i++].u = 0;
-  memory[16].u = OP_PRINT_STRING;
+  memory[i++].u = 104;
-  memory[17].u = 105;
+  memory[i++].u = OP_PRINT_STRING;
-  memory[18].u = 0;
+  memory[i++].u = 105;
-  memory[19].u = 0;
+  memory[i++].u = 0;
-  memory[20].u = OP_HALT;
+  memory[i++].u = 0;
+  memory[i++].u = OP_HALT;
   memory[100].u = 5;
   memory[101].u = 1;
   memory[102].f = 5.f;
@@ -196,19 +256,5 @@ int main() {
 
   run_vm();
 
-    FILE *file = fopen("memory_dump.bin", "wb");
+  return core_dump();
-    if (!file) {
-        perror("Failed to open file");
-        return EXIT_FAILURE;
-    }
-    size_t written = fwrite(memory, 1, MEMORY_SIZE, file);
-    if (written != MEMORY_SIZE) {
-        fprintf(stderr, "Incomplete write: %zu bytes written out of %u\n", written, MEMORY_SIZE);
-        fclose(file);
-        return EXIT_FAILURE;
-    }
-
-    fclose(file);
-
-  return 0;
 }