297     // min size. Either way, some users might have to set the region
 298     // size manually for some -Xms / -Xmx combos.
 299 
 300     region_size = MAX2(min_heap_size / TARGET_REGION_NUMBER,
 301                        (uintx) MIN_REGION_SIZE);
 302   }
 303 
 304   int region_size_log = log2_long((jlong) region_size);
 305   // Recalculate the region size to make sure it's a power of
 306   // 2. This means that region_size is the largest power of 2 that's
 307   // <= what we've calculated so far.
 308   region_size = ((uintx)1 << region_size_log);
 309 
 310   // Now make sure that we don't go over or under our limits.
 311   if (region_size < MIN_REGION_SIZE) {
 312     region_size = MIN_REGION_SIZE;
 313   } else if (region_size > MAX_REGION_SIZE) {
 314     region_size = MAX_REGION_SIZE;
 315   }
 316 





 317   // And recalculate the log.
 318   region_size_log = log2_long((jlong) region_size);
 319 
 320   // Now, set up the globals.
 321   guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
 322   LogOfHRGrainBytes = region_size_log;
 323 
 324   guarantee(LogOfHRGrainWords == 0, "we should only set it once");
 325   LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
 326 
 327   guarantee(GrainBytes == 0, "we should only set it once");
 328   // The cast to int is safe, given that we've bounded region_size by
 329   // MIN_REGION_SIZE and MAX_REGION_SIZE.
 330   GrainBytes = (size_t)region_size;
 331 
 332   guarantee(GrainWords == 0, "we should only set it once");
 333   GrainWords = GrainBytes >> LogHeapWordSize;
 334   guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity");
 335 
 336   guarantee(CardsPerRegion == 0, "we should only set it once");

 297     // min size. Either way, some users might have to set the region
 298     // size manually for some -Xms / -Xmx combos.
 299 
 300     region_size = MAX2(min_heap_size / TARGET_REGION_NUMBER,
 301                        (uintx) MIN_REGION_SIZE);
 302   }
 303 
 304   int region_size_log = log2_long((jlong) region_size);
 305   // Recalculate the region size to make sure it's a power of
 306   // 2. This means that region_size is the largest power of 2 that's
 307   // <= what we've calculated so far.
 308   region_size = ((uintx)1 << region_size_log);
 309 
 310   // Now make sure that we don't go over or under our limits.
 311   if (region_size < MIN_REGION_SIZE) {
 312     region_size = MIN_REGION_SIZE;
 313   } else if (region_size > MAX_REGION_SIZE) {
 314     region_size = MAX_REGION_SIZE;
 315   }
 316 
 317   if (region_size != G1HeapRegionSize) {
 318     // Update the flag to make sure that PrintFlagsFinal logs the correct value
 319     FLAG_SET_ERGO(uintx, G1HeapRegionSize, region_size);
 320   }
 321 
 322   // And recalculate the log.
 323   region_size_log = log2_long((jlong) region_size);
 324 
 325   // Now, set up the globals.
 326   guarantee(LogOfHRGrainBytes == 0, "we should only set it once");
 327   LogOfHRGrainBytes = region_size_log;
 328 
 329   guarantee(LogOfHRGrainWords == 0, "we should only set it once");
 330   LogOfHRGrainWords = LogOfHRGrainBytes - LogHeapWordSize;
 331 
 332   guarantee(GrainBytes == 0, "we should only set it once");
 333   // The cast to int is safe, given that we've bounded region_size by
 334   // MIN_REGION_SIZE and MAX_REGION_SIZE.
 335   GrainBytes = (size_t)region_size;
 336 
 337   guarantee(GrainWords == 0, "we should only set it once");
 338   GrainWords = GrainBytes >> LogHeapWordSize;
 339   guarantee((size_t) 1 << LogOfHRGrainWords == GrainWords, "sanity");
 340 
 341   guarantee(CardsPerRegion == 0, "we should only set it once");