fast block search part 2 - still ALPHA

now tested... it works but size is not optimal

src/engine/cmdStreamOps.cpp

@@ -601,7 +601,7 @@ void reloc(unsigned char* buf, size_t len, unsigned int sourceAddr, unsigned int
   }
 }
 
-SafeWriter* stripNops(SafeWriter* s, unsigned char* speedDial) {
+SafeWriter* stripNops(SafeWriter* s) {
   std::unordered_map<unsigned int,unsigned int> addrTable;
   SafeWriter* oldStream=s;
   unsigned char* buf=oldStream->getFinalBuf();
@@ -666,11 +666,18 @@ struct BlockMatch {
 
 #define OVERLAPS(a1,a2,b1,b2) ((b1)<(a2) && (b2)>(a1))
 
-SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlocks, unsigned char* speedDial) {
+// TODO:
+// - check whether a block consists only of calls
+// - see if we can optimize better
+SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlocks) {
   unsigned char* buf=stream->getFinalBuf();
   size_t matchSize=48;
   std::vector<BlockMatch> matches;
 
+  // repeat until we run out of matches
+  while (true) {
+    matches.clear();
+
     // fast match algorithm
     // search for small matches, and then find bigger ones
     for (size_t i=0; i<stream->size(); i+=8) {
@@ -720,7 +727,9 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
     } while (wantMore);
 
     // first stage done
-  // set done to false unless this match overlaps with itself
+    // set done to false unless:
+    // - this match overlaps with itself
+    // - this block only consists of calls
     size_t nonOverlapCount=0;
     for (BlockMatch& i: matches) {
       i.done=false;
@@ -729,10 +738,24 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
         i.done=true;
       } else {
         nonOverlapCount++;
+        /*
+        bool onlyCalls=true;
+        for (size_t j=i.orig; j<i.orig+i.len; j+=8) {
+          if (buf[j]!=0xf4) {
+            onlyCalls=false;
+            break;
+          }
+        }
+        if (onlyCalls) {
+          i.done=true;
+        } else {
+          nonOverlapCount++;
+        }
+        */
       }
     }
 
-  logD("%d non-overlapping candidates",(int)nonOverlapCount);
+    logD("%d good candidates",(int)nonOverlapCount);
 
     // quit if there isn't anything
     if (!nonOverlapCount) return stream;
@@ -742,6 +765,7 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
     logD("largest match: %d",(int)matchSize);
 
     std::vector<BlockMatch> workMatches;
+    bool newBlocks=false;
 
     while (matchSize>=48) {
       workMatches.clear();
@@ -764,6 +788,8 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
         // create new sub-block if necessary
         if (i.orig!=lastOrig) {
           subBlockID=subBlocks.size();
+          newBlocks=true;
+          logV("new sub-block %d",(int)subBlockID);
 
           // isolate this sub-block
           SafeWriter* newBlock=new SafeWriter;
@@ -846,126 +872,16 @@ SafeWriter* findSubBlocks(SafeWriter* stream, std::vector<SafeWriter*>& subBlock
 
     logV("done!");
 
+    // get out if we haven't made any blocks
+    if (!newBlocks) break;
+
     // remove nop's
-  stream=stripNops(stream,speedDial);
+    stream=stripNops(stream);
-
-  /*
-  for (size_t groupSize=stream->size()>>1; groupSize>=48; groupSize-=8) {
-    bool foundSomething=false;
-    logV("...try size %d",groupSize);
-    for (size_t searchPos=0; (searchPos+groupSize)<stream->size();) {
-      const unsigned char* group=&buf[searchPos];
-      size_t groupLen=0;
-      size_t groupInsCount=0;
-      size_t subBlockID=subBlocks.size();
-      bool haveSub=false;
-      bool onlyCalls=true;
-
-      // register this block
-      for (size_t i=0; i<groupSize && i<stream->size(); i+=8) {
-        if (buf[searchPos+i]!=0xf4) onlyCalls=false;
-        if (groupLen+8>groupSize) break;
-        groupLen+=8;
-        groupInsCount++;
-      }
-
-      // don't do anything if we don't have a block large enough
-      if (groupLen<24) {
-        searchPos+=8;
-        continue;
-      }
-
-      // don't do anything if this is just one or two commands
-      // TODO: this is a duplicate of the previous statement now that all commands are 8 bytes long
-      if (groupInsCount<3) {
-        searchPos+=8;
-        continue;
-      }
-
-      // don't do anything if this block only consists of calls
-      if (onlyCalls) {
-        logW("nothing but calls.");
-        searchPos+=8;
-        continue;
-      }
-
-      // find identical blocks
-      for (size_t i=searchPos+groupLen; i+groupLen<stream->size();) {
-        // compare next block to group
-        if (memcmp(&buf[i],group,groupLen)==0) {
-          // we have a sub-block
-          if (!haveSub) {
-            // isolate this sub-block
-            SafeWriter* newBlock=new SafeWriter;
-            newBlock->init();
-            newBlock->write(group,groupLen);
-            newBlock->writeC(0xf9); // ret
-            // padding
-            newBlock->writeC(0);
-            newBlock->writeC(0);
-            newBlock->writeC(0);
-            newBlock->writeC(0);
-            newBlock->writeC(0);
-            newBlock->writeC(0);
-            newBlock->writeC(0);
-            subBlocks.push_back(newBlock);
-            haveSub=true;
-          logD("- SUB %x (size %d):",searchPos,groupLen);
-          }
-          logD("  - %x",i);
-          // insert call
-          buf[i]=0xf4;
-          buf[i+1]=subBlockID&0xff;
-          buf[i+2]=(subBlockID>>8)&0xff;
-          buf[i+3]=(subBlockID>>16)&0xff;
-          buf[i+4]=(subBlockID>>24)&0xff;
-          buf[i+5]=0;
-          buf[i+6]=0;
-          buf[i+7]=0;
-
-          // replace the rest with nop
-          for (size_t j=i+8; j<i+groupLen; j++) {
-            buf[j]=0xf1;
-          }
-
-          // continue search from end of block
-          i+=groupLen;
-        } else {
-          // next
-          i+=8;
-        }
-      }
-
-      if (haveSub) {
-        // insert call on the original block
-        buf[searchPos]=0xf4;
-        buf[searchPos+1]=subBlockID&0xff;
-        buf[searchPos+2]=(subBlockID>>8)&0xff;
-        buf[searchPos+3]=(subBlockID>>16)&0xff;
-        buf[searchPos+4]=(subBlockID>>24)&0xff;
-        buf[searchPos+5]=0;
-        buf[searchPos+6]=0;
-        buf[searchPos+7]=0;
-
-        // replace the rest with nop
-        for (size_t j=searchPos+8; j<searchPos+groupLen; j++) {
-          buf[j]=0xf1;
-        }
-
-        // skip this block (it's isolated now)
-        searchPos+=groupLen;
-        foundSomething=true;
-      } else {
-        // try again somewhere else
-        searchPos+=8;
-      }
-    }
-    if (foundSomething) {
-      stream=stripNops(stream,speedDial);
     buf=stream->getFinalBuf();
+
+    logV("doing it again...");
   }
-  }
+
-  */
   return stream;
 }
 
@@ -1343,7 +1259,7 @@ SafeWriter* DivEngine::saveCommand(DivCSProgress* progress, unsigned int disable
   // PASS 3: remove nop's
   // this includes modifying call addresses to compensate
   for (int h=0; h<chans; h++) {
-    chanStream[h]=stripNops(chanStream[h],sortedCmd);
+    chanStream[h]=stripNops(chanStream[h]);
   }
 
   // PASS 4: find sub-blocks and isolate them
@@ -1354,7 +1270,7 @@ SafeWriter* DivEngine::saveCommand(DivCSProgress* progress, unsigned int disable
       
       // 6 is the minimum size that can be reliably optimized
       logI("finding sub-blocks in chan %d",h);
-      chanStream[h]=findSubBlocks(chanStream[h],subBlocks,sortedCmd);
+      chanStream[h]=findSubBlocks(chanStream[h],subBlocks);
       // find sub-blocks within sub-blocks
       size_t subBlocksLast=0;
       size_t subBlocksLen=subBlocks.size();
@@ -1362,7 +1278,7 @@ SafeWriter* DivEngine::saveCommand(DivCSProgress* progress, unsigned int disable
       while (subBlocksLast!=subBlocksLen) {
         logI("got %d blocks... starting from %d",(int)subBlocksLen,(int)subBlocksLast);
         for (size_t i=subBlocksLast; i<subBlocksLen; i++) {
-          SafeWriter* newBlock=findSubBlocks(subBlocks[i],subBlocks,sortedCmd);
+          SafeWriter* newBlock=findSubBlocks(subBlocks[i],subBlocks);
           subBlocks[i]=newBlock;
         }
         subBlocksLast=subBlocksLen;
@@ -1433,7 +1349,7 @@ SafeWriter* DivEngine::saveCommand(DivCSProgress* progress, unsigned int disable
 
   // PASS 5: remove nop's (again)
   for (int h=0; h<chans; h++) {
-    chanStream[h]=stripNops(chanStream[h],sortedCmd);
+    chanStream[h]=stripNops(chanStream[h]);
   }
 
   // PASS 6: pack streams