Changeset 2996

Timestamp:

Apr 3, 2013, 6:38:32 PM (4 years ago)

Author:

cameron

Message:

Process bits in little-endian order; add bit_pattern_expr

File:

• proto/charsetcompiler/charset_compiler.py (modified) (5 diffs)

proto/charsetcompiler/charset_compiler.py

@@ -246 +246 @@
     return options.basis_pattern % n
 def make_bitv(n):
-    return Var(bit_var(n))
+    return Var(bit_var(7-n))
 
 
@@ -255 +255 @@
     for i in range(0, bit_count):
         if (pattern & test_bit) == 0:
-            bit_terms.append(make_not(make_bitv(i)))
-        else: bit_terms.append(make_bitv(i))
+            bit_terms.append(make_not(make_bitv(7-i)))
+        else: bit_terms.append(make_bitv(7-i))
         test_bit >>= 1
     while len(bit_terms) > 1:
@@ -267 +267 @@
     return bit_terms[0]
 
+def bit_pattern_expr(pattern, selected_bits):
+    if selected_bits == 0: return TrueLiteral()
+    bit_terms = []
+    bit_no = 0
+    while selected_bits:
+      test_bit = 1 << bit_no
+      if selected_bits & test_bit:
+        if (pattern & test_bit) == 0:
+            bit_terms = [make_not(make_bitv(bit_no))] + bit_terms
+        else: bit_terms = [make_bitv(bit_no)] + bit_terms
+      else: bit_terms = [TrueLiteral()] + bit_terms
+      # Appending TrueLiteral() for nonselected bits is intended
+      # to keep consistent grouping of variables in the next loop.
+      selected_bits &= ~test_bit
+      bit_no += 1
+    while len(bit_terms) > 1:
+        new_terms = []
+        for i in range(0, len(bit_terms)/ 2):
+            new_terms.append(make_and(bit_terms[2*i], bit_terms[2*i+1]))
+        if len(bit_terms) % 2 == 1:
+            new_terms.append(bit_terms[-1])
+        bit_terms = new_terms
+    return bit_terms[0]
+    
 
 def char_test_expr(ch):
-    return make_bit_test(ord(ch), 8)
-    #return make_8bit_test(ord(ch))
+    #return make_bit_test(ord(ch), 8)
+    return bit_pattern_expr(ord(ch), 0xFF)
 
 def GE_Range(N, n):
     if N == 0: return TrueLiteral()
     elif N % 2 == 0 and (n >> (N - 2)) == 0:
-        return make_or(make_or(make_bitv(8-N), make_bitv(9-N)),
+        return make_or(make_or(make_bitv(N-1), make_bitv(N-2)),
                         GE_Range(N - 2, n))
     elif N % 2 == 0 and (n >> (N - 2)) == 3:   # >= 11xxxx 
-        return make_and(make_and(make_bitv(8-N), make_bitv(9-N)),
+        return make_and(make_and(make_bitv(N-1), make_bitv(N-2)),
                         GE_Range(N - 2, n - (3 << (N-2))))
     elif N >= 1:
@@ -288 +312 @@
             # is set in the target, the target will certainly be >=.  Otherwise,
             # the value of GE_range(N-1, lo_bits) is required.
-            return make_or(make_bitv(8-N), lo_range)
+            return make_or(make_bitv(N-1), lo_range)
         else: 
             # If the hi_bit of n is set, then the corresponding bit must be set
             # in the target for >= and GE_range(N-1, lo_bits) must also be true.
-            return make_and(make_bitv(8-N), lo_range)
+            return make_and(make_bitv(N-1), lo_range)
 
 def LE_Range(N, n):
@@ -314 +338 @@
         diff_bits >>= 1
     if n2 < n1 or diff_count > 8: raise BadRange()
-    mask = 2**(diff_count-1) - 1
-    common = make_bit_test(n1 >> diff_count, 8 - diff_count)
+    mask = 2**(diff_count) - 1
+    #common = make_bit_test(n1 >> diff_count, 8 - diff_count)
+    common = bit_pattern_expr(n1 & ~mask, 0xFF^mask)
     if diff_count == 0: return common
     mask = 2**(diff_count-1) - 1
     lo_test = GE_Range(diff_count-1, n1 & mask)
     hi_test = LE_Range(diff_count-1, n2 & mask)
-    return make_and(common, make_sel(make_bitv(8-diff_count), hi_test, lo_test))
+    return make_and(common, make_sel(make_bitv(diff_count-1), hi_test, lo_test))
 
 BadCharSetItem = Exception()