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src/hotspot/share/opto/parse2.cpp

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1260     prob = (0+PROB_MIN) / 2;
1261   else if( !not_taken )
1262     prob = (1+PROB_MAX) / 2;
1263   else {                         // Compute probability of true path
1264     prob = (float)taken / (float)(taken + not_taken);
1265     if (prob > PROB_MAX)  prob = PROB_MAX;
1266     if (prob < PROB_MIN)   prob = PROB_MIN;
1267   }
1268 
1269   assert((cnt > 0.0f) && (prob > 0.0f),
1270          "Bad frequency assignment in if cnt=%g prob=%g taken=%d not_taken=%d", cnt, prob, taken, not_taken);
1271 
1272   if (C->log() != nullptr) {
1273     const char* prob_str = nullptr;
1274     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
1275     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
1276     char prob_str_buf[30];
1277     if (prob_str == nullptr) {
1278       jio_snprintf(prob_str_buf, sizeof(prob_str_buf), "%20.2f", prob);
1279       prob_str = prob_str_buf;






1280     }
1281     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%f' prob='%s'",
1282                    iter().get_dest(), taken, not_taken, cnt, prob_str);
1283   }
1284   return prob;
1285 }
1286 
1287 //-----------------------------branch_prediction-------------------------------
1288 float Parse::branch_prediction(float& cnt,
1289                                BoolTest::mask btest,
1290                                int target_bci,
1291                                Node* test) {
1292   float prob = dynamic_branch_prediction(cnt, btest, test);
1293   // If prob is unknown, switch to static prediction
1294   if (prob != PROB_UNKNOWN)  return prob;
1295 
1296   prob = PROB_FAIR;                   // Set default value
1297   if (btest == BoolTest::eq)          // Exactly equal test?
1298     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
1299   else if (btest == BoolTest::ne)

1260     prob = (0+PROB_MIN) / 2;
1261   else if( !not_taken )
1262     prob = (1+PROB_MAX) / 2;
1263   else {                         // Compute probability of true path
1264     prob = (float)taken / (float)(taken + not_taken);
1265     if (prob > PROB_MAX)  prob = PROB_MAX;
1266     if (prob < PROB_MIN)   prob = PROB_MIN;
1267   }
1268 
1269   assert((cnt > 0.0f) && (prob > 0.0f),
1270          "Bad frequency assignment in if cnt=%g prob=%g taken=%d not_taken=%d", cnt, prob, taken, not_taken);
1271 
1272   if (C->log() != nullptr) {
1273     const char* prob_str = nullptr;
1274     if (prob >= PROB_MAX)  prob_str = (prob == PROB_MAX) ? "max" : "always";
1275     if (prob <= PROB_MIN)  prob_str = (prob == PROB_MIN) ? "min" : "never";
1276     char prob_str_buf[30];
1277     if (prob_str == nullptr) {
1278       jio_snprintf(prob_str_buf, sizeof(prob_str_buf), "%20.2f", prob);
1279       prob_str = prob_str_buf;
1280       // The %20.2f adds many spaces to the string, to avoid some
1281       // picky overflow warning as noted in 8211929.  But, 20 is the
1282       // *minimum* width, not *maximum*, so it's not clear how this
1283       // helps prevent overflow.  Looks like we were forced to work
1284       // around a bug in gcc.  In any case, strip the blanks.
1285       while (*prob_str == ' ')  ++prob_str;
1286     }
1287     C->log()->elem("branch target_bci='%d' taken='%d' not_taken='%d' cnt='%f' prob='%s'",
1288                    iter().get_dest(), taken, not_taken, cnt, prob_str);
1289   }
1290   return prob;
1291 }
1292 
1293 //-----------------------------branch_prediction-------------------------------
1294 float Parse::branch_prediction(float& cnt,
1295                                BoolTest::mask btest,
1296                                int target_bci,
1297                                Node* test) {
1298   float prob = dynamic_branch_prediction(cnt, btest, test);
1299   // If prob is unknown, switch to static prediction
1300   if (prob != PROB_UNKNOWN)  return prob;
1301 
1302   prob = PROB_FAIR;                   // Set default value
1303   if (btest == BoolTest::eq)          // Exactly equal test?
1304     prob = PROB_STATIC_INFREQUENT;    // Assume its relatively infrequent
1305   else if (btest == BoolTest::ne)
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