8298813: [C2] Converting double to float cause a loss of precision and resulting crypto.aes scores fluctuate

Reviewed-by: thartmann

Author: sunny868

src/hotspot/share/opto/chaitin.hpp

@@ -478,7 +478,7 @@ class PhaseChaitin : public PhaseRegAlloc {
 
   Block **_blks;                // Array of blocks sorted by frequency for coalescing
 
-  float _high_frequency_lrg;    // Frequency at which LRG will be spilled for debug info
+  double _high_frequency_lrg;   // Frequency at which LRG will be spilled for debug info
 
 #ifndef PRODUCT
   bool _trace_spilling;
@@ -495,7 +495,7 @@ class PhaseChaitin : public PhaseRegAlloc {
   // Do all the real work of allocate
   void Register_Allocate();
 
-  float high_frequency_lrg() const { return _high_frequency_lrg; }
+  double high_frequency_lrg() const { return _high_frequency_lrg; }
 
   // Used when scheduling info generated, not in general register allocation
   bool _scheduling_info_generated;