8274242: Implement fast-path for ASCII-compatible CharsetEncoders on x86

src/hotspot/cpu/aarch64/matcher_aarch64.hpp

@@ -160,4 +160,7 @@
       return true;
   }
 
+  // Implements a variant of EncodeISOArrayNode that encode ASCII only
+  static const bool supports_encode_ascii_array = false;
+
 #endif // CPU_AARCH64_MATCHER_AARCH64_HPP

src/hotspot/cpu/arm/matcher_arm.hpp

@@ -152,4 +152,7 @@
       return false;
   }
 
+  // Implements a variant of EncodeISOArrayNode that encode ASCII only
+  static const bool supports_encode_ascii_array = false;
+
 #endif // CPU_ARM_MATCHER_ARM_HPP

src/hotspot/cpu/ppc/matcher_ppc.hpp

@@ -161,5 +161,7 @@
     return VM_Version::has_fcfids();
   }
 
+  // Implements a variant of EncodeISOArrayNode that encode ASCII only
+  static const bool supports_encode_ascii_array = false;
 
 #endif // CPU_PPC_MATCHER_PPC_HPP

src/hotspot/cpu/s390/matcher_s390.hpp

@@ -149,4 +149,7 @@
       return true;
   }
 
+  // Implements a variant of EncodeISOArrayNode that encode ASCII only
+  static const bool supports_encode_ascii_array = false;
+
 #endif // CPU_S390_MATCHER_S390_HPP

src/hotspot/cpu/x86/matcher_x86.hpp

@@ -192,4 +192,7 @@
       return true;
   }
 
+  // Implements a variant of EncodeISOArrayNode that encode ASCII only
+  static const bool supports_encode_ascii_array = true;
+
 #endif // CPU_X86_MATCHER_X86_HPP

src/hotspot/share/opto/c2compiler.cpp

@@ -217,9 +217,8 @@ bool C2Compiler::is_intrinsic_supported(const methodHandle& method, bool is_virt
     if (StubRoutines::unsafe_arraycopy() == NULL) return false;
     break;
   case vmIntrinsics::_encodeAsciiArray:
-#if !defined(X86)
-    return false; // not yet implemented
-#endif
+    if (!Matcher::match_rule_supported(Op_EncodeISOArray) && !Matcher::supports_encode_ascii_array) return false;
+    break;
   case vmIntrinsics::_encodeISOArray:
   case vmIntrinsics::_encodeByteISOArray:
     if (!Matcher::match_rule_supported(Op_EncodeISOArray)) return false;