rtlil: rewrite remove2() to avoid copying

diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index dfccc78f87fa43da2aadb657a33d823837ce9efe..7878eaae7b79d7aa4f5bb47f622615f6f8f46997 100644 (file)
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -2688,31 +2688,15 @@ void RTLIL::SigSpec::remove2(const pool<RTLIL::SigBit> &pattern, RTLIL::SigSpec
                other->unpack();
        }
 
-       std::vector<RTLIL::SigBit> new_bits, new_other_bits;
-
-       new_bits.resize(GetSize(bits_));
-       if (other != NULL)
-               new_other_bits.resize(GetSize(bits_));
-
-       int k = 0;
-       for (int i = 0; i < GetSize(bits_); i++) {
-               if (bits_[i].wire != NULL && pattern.count(bits_[i]))
-                       continue;
-               if (other != NULL)
-                       new_other_bits[k] = other->bits_[i];
-               new_bits[k++] = bits_[i];
-       }
-
-       new_bits.resize(k);
-       if (other != NULL)
-               new_other_bits.resize(k);
-
-       bits_.swap(new_bits);
-       width_ = GetSize(bits_);
-
-       if (other != NULL) {
-               other->bits_.swap(new_other_bits);
-               other->width_ = GetSize(other->bits_);
+       for (int i = GetSize(bits_) - 1; i >= 0; i--) {
+               if (bits_[i].wire != NULL && pattern.count(bits_[i])) {
+                       bits_.erase(bits_.begin() + i);
+                       width_--;
+                       if (other != NULL) {
+                               other->bits_.erase(other->bits_.begin() + i);
+                               other->width_--;
+                       }
+               }
        }
 
        check();
@@ -2732,26 +2716,15 @@ void RTLIL::SigSpec::remove2(const std::set<RTLIL::SigBit> &pattern, RTLIL::SigS
                other->unpack();
        }
 
-       std::vector<RTLIL::SigBit> new_bits, new_other_bits;
-
-       new_bits.reserve(GetSize(bits_));
-       if (other != NULL)
-               new_other_bits.reserve(GetSize(bits_));
-
-       for (int i = 0; i < GetSize(bits_); i++) {
-               if (bits_[i].wire != NULL && pattern.count(bits_[i]))
-                       continue;
-               if (other != NULL)
-                       new_other_bits.push_back(other->bits_[i]);
-               new_bits.push_back(bits_[i]);
-       }
-
-       bits_.swap(new_bits);
-       width_ = GetSize(bits_);
-
-       if (other != NULL) {
-               other->bits_.swap(new_other_bits);
-               other->width_ = GetSize(other->bits_);
+       for (int i = GetSize(bits_) - 1; i >= 0; i--) {
+               if (bits_[i].wire != NULL && pattern.count(bits_[i])) {
+                       bits_.erase(bits_.begin() + i);
+                       width_--;
+                       if (other != NULL) {
+                               other->bits_.erase(other->bits_.begin() + i);
+                               other->width_--;
+                       }
+               }
        }
 
        check();