X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Ftv%2Ftv.c;h=90d24bb7ad3bd40faa932986cb3544f0d5de6553;hb=464132f4d8840f7bb4228bfeef5484331bf50835;hp=5c6b09bfe19e5a004233907eb63ae5b68c0c26fb;hpb=ecdae24c2bf7aa79d8065255940faae70307d535;p=libfirm

diff --git a/ir/tv/tv.c b/ir/tv/tv.c
index 5c6b09bfe..90d24bb7a 100644
--- a/ir/tv/tv.c
+++ b/ir/tv/tv.c
@@ -191,13 +191,8 @@ static tarval *get_tarval_overflow(const void *value, int length, ir_mode *mode)
           case TV_OVERFLOW_WRAP:
             {
               char *temp = alloca(sc_get_buffer_length());
-              char *diff = alloca(sc_get_buffer_length());
-              sc_sub(get_mode_max(mode)->value, get_mode_min(mode)->value, diff);
-              sc_val_from_ulong(1, temp);
-              sc_add(diff, temp, diff);
-              sc_sub(value, diff, temp);
-              while (sc_comp(temp, get_mode_max(mode)->value) == 1)
-                sc_sub(temp, diff, temp);
+              sc_val_from_ulong(-1, temp);
+              sc_and(temp, value, temp);
               return get_tarval(temp, length, mode);
             }
           case TV_OVERFLOW_BAD:
@@ -213,13 +208,8 @@ static tarval *get_tarval_overflow(const void *value, int length, ir_mode *mode)
           case TV_OVERFLOW_WRAP:
             {
               char *temp = alloca(sc_get_buffer_length());
-              char *diff = alloca(sc_get_buffer_length());
-              sc_sub(get_mode_max(mode)->value, get_mode_min(mode)->value, diff);
-              sc_val_from_ulong(1, temp);
-              sc_add(diff, temp, diff);
-              sc_add(value, diff, temp);
-              while (sc_comp(temp, get_mode_max(mode)->value) == 1)
-                sc_add(temp, diff, temp);
+              sc_val_from_ulong(-1, temp);
+              sc_and(temp, value, temp);
               return get_tarval(temp, length, mode);
             }
           case TV_OVERFLOW_BAD:
@@ -1521,20 +1511,20 @@ int tarval_snprintf(char *buf, size_t len, tarval *tv)
 
     case irms_reference:
       if (tv == tv->mode->null) return snprintf(buf, len, "NULL");
-      if (tv->value != NULL){
-      if (len > tv->length) {
-        memcpy(buf, tv->value, tv->length);
-        buf[tv->length] = '\0';
-      }
-      else {
-        /* truncated */
-        memcpy(buf, tv->value, len-1);
-        buf[len-1] = '\0';
+      if (tv->value != NULL) {
+        if (len > tv->length) {
+          memcpy(buf, tv->value, tv->length);
+          buf[tv->length] = '\0';
+        }
+        else {
+          /* truncated */
+          memcpy(buf, tv->value, len-1);
+          buf[len-1] = '\0';
+        }
+        return tv->length;
       }
-      return tv->length;
-         }
       else
-    return snprintf(buf, len, "void");
+        return snprintf(buf, len, "void");
 
     case irms_internal_boolean:
       switch (mode_info->mode_output) {
@@ -1664,7 +1654,33 @@ tarval_classification_t classify_tarval(tarval *tv)
   return TV_CLASSIFY_OTHER;
 }
 
-/**
+/*
+ * Returns non-zero if a given (integer) tarval has only one single bit
+ * set.
+ */
+int is_single_bit_tarval(tarval *tv) {
+  int i, l;
+  int bits;
+
+  if (!tv || tv == tarval_bad) return 0;
+  if (! mode_is_int(tv->mode)) return 0;
+
+  l = get_mode_size_bytes(tv->mode);
+  for (bits = 0, i = l - 1; i >= 0; --i) {
+    unsigned char v = get_tarval_sub_bits(tv, (unsigned)i);
+
+    /* check for more than one bit in these */
+    if (v) {
+      if (v & (v-1))
+        return 0;
+      if (++bits > 1)
+        return 0;
+    }
+  }
+  return bits;
+}
+
+/*
  * Sets the overflow mode for integer operations.
  */
 void tarval_set_integer_overflow_mode(tarval_int_overflow_mode_t ov_mode) {