initial commit

1 files changed, 54 insertions, 0 deletions

diff --git a/comp1521/smips/helper.c b/comp1521/smips/helper.c
new file mode 100644
index 0000000..ebe798b
--- /dev/null
+++ b/comp1521/smips/helper.c
@@ -0,0 +1,54 @@
+#include "helper.h"
+
+// Returns the n'th bit of a uint32_t value.
+uint32_t get_nth_bit(const uint32_t value, const int n) {
+    return (value & (1u << n)) >> n;
+}
+
+// Prints the bits of a uint32_t value.
+void print_bits(const uint32_t value) {
+    for (int i = (int)sizeof(uint32_t)*8-1; i >= 0; --i) {
+        printf("%d", get_nth_bit(value, i));
+    }
+    printf("\n");
+}
+
+// Skips past the next newline. 
+// If EOF, stays on EOF so that subsequent fgetc() calls return EOF.
+void skip_past_newline(FILE *const fptr) {
+    int c = 0;
+    c = fgetc(fptr);
+    while (true) {
+        if (c == EOF) {
+            fseek(fptr, -1L, SEEK_CUR);
+            return;
+        }
+        else if (c == '\n') {
+            printf("newline\n");
+            return;
+        } else {
+            fseek(fptr, -1L, SEEK_CUR);
+            return;
+        }
+        printf("skipping char\n");
+        c = fgetc(fptr);
+    }
+}
+
+// Converts decimal values to hex obviously.
+uint32_t hex_to_decimal(const uint32_t decimal) {
+    uint32_t ret = 0;
+    for (size_t i = 0; i < sizeof(uint32_t); ++i) { // Iterate through 4 bytes.
+        uint32_t tmp = (decimal & (0xFFu << 8*i)) >> 8*i;
+        if (isalpha(tmp)) {
+            tmp -= 'a';
+            tmp += 10;
+        }
+        else if (isdigit(tmp)) {
+            tmp -= '0';
+        } 
+        // There should be no other cases if the input is hex.
+        ret |= (tmp << 4*i);
+    }
+    return ret;
+}