little progress ...

[r15959]

diff --git a/ir/tv/tc_calc.c b/ir/tv/tc_calc.c
index ff476b8..4e266ee 100644 (file)
--- a/ir/tv/tc_calc.c
+++ b/ir/tv/tc_calc.c
@@ -66,9 +66,15 @@ void tc_eor(const tc_value *a, const tc_value *b, tc_value *res) {
 /**
  * Compare two tc_value's.
  */
-pn_Cmp tc_cmp(const tc_value *a, const tc_value *b) {
+pn_Cmp tc_cmp(const tc_value *a, const tc_value *b, int signed_cmp) {
        int i;
 
+       if (signed_cmp) {
+               int sign_a = SIGN(a);
+
+               if (sign_a != !SIGN(b))
+                       return sign_a ? pn_Cmp_Lt : pn_Cmp_Gt;
+       }
        for (i = 0; i < NUM_VALUE_PARTS; ++i) {
                if (a->part[i] > b->part[i])
                        return pn_Cmp_Gt;
@@ -166,7 +172,7 @@ static void _tc_umul(const tc_value *a, const tc_value *b, tc_value_part *w) {
 /**
  * Multiply two unsigned tc_values: res = a * b.
  */
-static void tc_umul(const tc_value *a, const tc_value *b, tc_value *res) {
+void tc_umul(const tc_value *a, const tc_value *b, tc_value *res) {
        tc_value_part w[NUM_WORK_PARTS];
        int i, ov = 0;
 
@@ -186,36 +192,11 @@ static void tc_umul(const tc_value *a, const tc_value *b, tc_value *res) {
        tc_Overflow = tc_Carry = ov;
 }
 
-/* Matze: this function was defined 2 times... */
-#if 0
-/**
- * Multiply two unsigned tc_values: res = a * b.
- */
-static void tc_umul(const tc_value *a, const tc_value *b, tc_value *res) {
-       unsigned tc_value_part w[NUM_WORK_PARTS];
-       int i, ov = 0;
-
-       _tc_umul(a, b, w);
-
-       /* copy the lower result bits */
-       for (i = 0; i < NUM_VALUE_PARTS; ++i)
-               res->part[i] = (tc_value_part)w[i];
-
-       /* check for overflow */
-       for (; i < NUM_WORK_PARTS; ++i) {
-               if (w[i] != 0) {
-                       ov = 0;
-                       break;
-               }
-       }
-       tc_Overflow = tc_Carry = ov;
-}
-#endif
 
 /**
  * Multiply two signed tc_values: res = a * b.
  */
-static void tc_smul(const tc_value *a, const tc_value *b, tc_value *res) {
+void tc_smul(const tc_value *a, const tc_value *b, tc_value *res) {
        tc_value_part w[NUM_WORK_PARTS];
        int i, ov = 0, neg_res = 0;
        const tc_value *u = a, *v = b;
@@ -251,3 +232,36 @@ static void tc_smul(const tc_value *a, const tc_value *b, tc_value *res) {
 
        tc_Overflow = tc_Carry = ov;
 }
+
+/**
+ * Multiply two unsigned tc_values: divres = a / b, modres = a % b.
+ */
+static void _tc_divmodu(const tc_value *a, const tc_value *b, tc_value **divres, tc_value **modres) {
+       static tc_value zero;
+       int overflow;
+
+       /* Check for division by 0, 0 / x, and a < b */
+       tc_from_long(&zero, 0);
+       if (tc_cmp(b, &zero, 0) == pn_Cmp_Eq) {
+               /* div by zero. */
+               *divres = &zero;
+               *modres = &zero;
+               tc_Carry = tc_Overflow = 1;
+               return;
+       }
+       if (tc_cmp(a, &zero, 0) == pn_Cmp_Eq) {
+               /* 0 / b = 0 */
+               *divres = &zero;
+               *modres = &zero;
+               tc_Carry = tc_Overflow = 0;
+               return;
+       }
+       if (tc_cmp(a, b, 0) == pn_Cmp_Lt) {
+               /* a < b ==> a / b = 0 mod a */
+               *divres = &zero;
+               *modres = a;
+               tc_Carry = tc_Overflow = 0;
+               return;
+       }
+
+}