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path: root/sem3/osc/mm11/regn/symtab.c
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-rw-r--r--sem3/osc/mm11/regn/symtab.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/sem3/osc/mm11/regn/symtab.c b/sem3/osc/mm11/regn/symtab.c
new file mode 100644
index 0000000..8103203
--- /dev/null
+++ b/sem3/osc/mm11/regn/symtab.c
@@ -0,0 +1,50 @@
+#include "symtab.h"
+#include <stdlib.h>
+#include <string.h>
+
+unsigned int hash(char *s) {
+ uint32_t hv = 0;
+ for( int i = 0; s[i] != '\0'; i++ ) {
+ // take MSB 6 bits of hv and xors with LSB of s[i]
+ uint32_t v = ( hv >> 26 ) ^ (s[i] & 0x3f);
+
+ // Push those back on hv
+ hv = (hv << 4) | v;
+ }
+ // Return appropriate size
+ return hv % HASHSIZE;
+}
+
+
+symnode_t *sym_insert(char *var) {
+ unsigned int index = hash(var);
+
+ // Save old value
+ symnode_t *oldSym = symbolarray[index];
+
+ // Make new
+ symbolarray[index] = malloc(sizeof(symnode_t));
+ if( symbolarray[index] == NULL ) {
+ // If malloc failed
+ symbolarray[index] = oldSym;
+ return NULL;
+ }
+
+ // Link old one
+ symbolarray[index]->next = oldSym;
+ symbolarray[index]->name = var;
+
+ return symbolarray[index];
+}
+
+symnode_t *sym_lookup(char *var) {
+ unsigned int index = hash(var);
+ symnode_t *n = symbolarray[index];
+
+ // Look trough list
+ while(n != NULL && strcmp(n->name, var) != 0) {
+ n = n->next;
+ }
+
+ return n;
+}