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

src/hotspot/cpu/aarch64/aarch64.ad

@@ -16855,6 +16855,7 @@ instruct encode_iso_array(iRegP_R2 src, iRegP_R1 dst, iRegI_R3 len,
                           vRegD_V2 Vtmp3, vRegD_V3 Vtmp4,
                           iRegI_R0 result, rFlagsReg cr)
 %{
+  predicate(!((EncodeISOArrayNode*)n)->is_ascii());
   match(Set result (EncodeISOArray src (Binary dst len)));
   effect(USE_KILL src, USE_KILL dst, USE_KILL len,
          KILL Vtmp1, KILL Vtmp2, KILL Vtmp3, KILL Vtmp4, KILL cr);

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/ppc/ppc.ad

@@ -12789,6 +12789,7 @@ instruct has_negatives(rarg1RegP ary1, iRegIsrc len, iRegIdst result, iRegLdst t
 // encode char[] to byte[] in ISO_8859_1
 instruct encode_iso_array(rarg1RegP src, rarg2RegP dst, iRegIsrc len, iRegIdst result, iRegLdst tmp1,
                           iRegLdst tmp2, iRegLdst tmp3, iRegLdst tmp4, iRegLdst tmp5, regCTR ctr, flagsRegCR0 cr0) %{
+  predicate(!((EncodeISOArrayNode*)n)->is_ascii());
   match(Set result (EncodeISOArray src (Binary dst len)));
   effect(TEMP_DEF result, TEMP tmp1, TEMP tmp2, TEMP tmp3, TEMP tmp4, TEMP tmp5,
          USE_KILL src, USE_KILL dst, KILL ctr, KILL cr0);

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/s390/s390.ad

@@ -10282,6 +10282,7 @@ instruct has_negatives(rarg5RegP ary1, iRegI len, iRegI result, roddRegI oddReg,
 
 // encode char[] to byte[] in ISO_8859_1
 instruct encode_iso_array(iRegP src, iRegP dst, iRegI result, iRegI len, iRegI tmp, flagsReg cr) %{
+  predicate(!((EncodeISOArrayNode*)n)->is_ascii());
   match(Set result (EncodeISOArray src (Binary dst len)));
   effect(TEMP_DEF result, TEMP tmp, KILL cr); // R0, R1 are killed, too.
   ins_cost(300);

src/hotspot/cpu/x86/macroAssembler_x86.cpp

@@ -5414,7 +5414,7 @@ void MacroAssembler::generate_fill(BasicType t, bool aligned,
   BIND(L_exit);
 }
 
-// encode char[] to byte[] in ISO_8859_1
+// encode char[] to byte[] in ISO_8859_1 or ASCII
    //@IntrinsicCandidate
    //private static int implEncodeISOArray(byte[] sa, int sp,
    //byte[] da, int dp, int len) {
@@ -5427,10 +5427,23 @@ void MacroAssembler::generate_fill(BasicType t, bool aligned,
    //  }
    //  return i;
    //}
+   //
+   //@IntrinsicCandidate
+   //private static int implEncodeAsciiArray(char[] sa, int sp,
+   //    byte[] da, int dp, int len) {
+   //  int i = 0;
+   //  for (; i < len; i++) {
+   //    char c = sa[sp++];
+   //    if (c >= '\u0080')
+   //      break;
+   //    da[dp++] = (byte)c;
+   //  }
+   //  return i;
+   //}
 void MacroAssembler::encode_iso_array(Register src, Register dst, Register len,
   XMMRegister tmp1Reg, XMMRegister tmp2Reg,
   XMMRegister tmp3Reg, XMMRegister tmp4Reg,
-  Register tmp5, Register result) {
+  Register tmp5, Register result, bool ascii) {
 
   // rsi: src
   // rdi: dst
@@ -5441,6 +5454,9 @@ void MacroAssembler::encode_iso_array(Register src, Register dst, Register len,
   assert_different_registers(src, dst, len, tmp5, result);
   Label L_done, L_copy_1_char, L_copy_1_char_exit;
 
+  int mask = ascii ? 0xff80ff80 : 0xff00ff00;
+  int short_mask = ascii ? 0xff80 : 0xff00;
+
   // set result
   xorl(result, result);
   // check for zero length
@@ -5460,7 +5476,7 @@ void MacroAssembler::encode_iso_array(Register src, Register dst, Register len,
 
     if (UseAVX >= 2) {
       Label L_chars_32_check, L_copy_32_chars, L_copy_32_chars_exit;
-      movl(tmp5, 0xff00ff00);   // create mask to test for Unicode chars in vector
+      movl(tmp5, mask);   // create mask to test for Unicode or non-ASCII chars in vector
       movdl(tmp1Reg, tmp5);
       vpbroadcastd(tmp1Reg, tmp1Reg, Assembler::AVX_256bit);
       jmp(L_chars_32_check);
@@ -5469,7 +5485,7 @@ void MacroAssembler::encode_iso_array(Register src, Register dst, Register len,
       vmovdqu(tmp3Reg, Address(src, len, Address::times_2, -64));
       vmovdqu(tmp4Reg, Address(src, len, Address::times_2, -32));
       vpor(tmp2Reg, tmp3Reg, tmp4Reg, /* vector_len */ 1);
-      vptest(tmp2Reg, tmp1Reg);       // check for Unicode chars in  vector
+      vptest(tmp2Reg, tmp1Reg);       // check for Unicode or non-ASCII chars in vector
       jccb(Assembler::notZero, L_copy_32_chars_exit);
       vpackuswb(tmp3Reg, tmp3Reg, tmp4Reg, /* vector_len */ 1);
       vpermq(tmp4Reg, tmp3Reg, 0xD8, /* vector_len */ 1);
@@ -5484,7 +5500,7 @@ void MacroAssembler::encode_iso_array(Register src, Register dst, Register len,
       jccb(Assembler::greater, L_copy_16_chars_exit);
 
     } else if (UseSSE42Intrinsics) {
-      movl(tmp5, 0xff00ff00);   // create mask to test for Unicode chars in vector
+      movl(tmp5, mask);   // create mask to test for Unicode or non-ASCII chars in vector
       movdl(tmp1Reg, tmp5);
       pshufd(tmp1Reg, tmp1Reg, 0);
       jmpb(L_chars_16_check);
@@ -5508,7 +5524,7 @@ void MacroAssembler::encode_iso_array(Register src, Register dst, Register len,
         movdqu(tmp4Reg, Address(src, len, Address::times_2, -16));
         por(tmp2Reg, tmp4Reg);
       }
-      ptest(tmp2Reg, tmp1Reg);       // check for Unicode chars in  vector
+      ptest(tmp2Reg, tmp1Reg);       // check for Unicode or non-ASCII chars in vector
       jccb(Assembler::notZero, L_copy_16_chars_exit);
       packuswb(tmp3Reg, tmp4Reg);
     }
@@ -5546,7 +5562,7 @@ void MacroAssembler::encode_iso_array(Register src, Register dst, Register len,
 
   bind(L_copy_1_char);
   load_unsigned_short(tmp5, Address(src, len, Address::times_2, 0));
-  testl(tmp5, 0xff00);      // check if Unicode char
+  testl(tmp5, short_mask);      // check if Unicode or non-ASCII char
   jccb(Assembler::notZero, L_copy_1_char_exit);
   movb(Address(dst, len, Address::times_1, 0), tmp5);
   addptr(len, 1);

src/hotspot/cpu/x86/macroAssembler_x86.hpp

@@ -1724,7 +1724,7 @@ class MacroAssembler: public Assembler {
 
   void encode_iso_array(Register src, Register dst, Register len,
                         XMMRegister tmp1, XMMRegister tmp2, XMMRegister tmp3,
-                        XMMRegister tmp4, Register tmp5, Register result);
+                        XMMRegister tmp4, Register tmp5, Register result, bool ascii);
 
 #ifdef _LP64
   void add2_with_carry(Register dest_hi, Register dest_lo, Register src1, Register src2);

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/cpu/x86/x86_32.ad

@@ -12199,18 +12199,35 @@ instruct string_inflate_evex(Universe dummy, eSIRegP src, eDIRegP dst, eDXRegI l
 instruct encode_iso_array(eSIRegP src, eDIRegP dst, eDXRegI len,
                           regD tmp1, regD tmp2, regD tmp3, regD tmp4,
                           eCXRegI tmp5, eAXRegI result, eFlagsReg cr) %{
+  predicate(!((EncodeISOArrayNode*)n)->is_ascii());
   match(Set result (EncodeISOArray src (Binary dst len)));
   effect(TEMP tmp1, TEMP tmp2, TEMP tmp3, TEMP tmp4, USE_KILL src, USE_KILL dst, USE_KILL len, KILL tmp5, KILL cr);
 
-  format %{ "Encode array $src,$dst,$len -> $result    // KILL ECX, EDX, $tmp1, $tmp2, $tmp3, $tmp4, ESI, EDI " %}
+  format %{ "Encode iso array $src,$dst,$len -> $result    // KILL ECX, EDX, $tmp1, $tmp2, $tmp3, $tmp4, ESI, EDI " %}
   ins_encode %{
     __ encode_iso_array($src$$Register, $dst$$Register, $len$$Register,
                         $tmp1$$XMMRegister, $tmp2$$XMMRegister, $tmp3$$XMMRegister,
-                        $tmp4$$XMMRegister, $tmp5$$Register, $result$$Register);
+                        $tmp4$$XMMRegister, $tmp5$$Register, $result$$Register, false);
   %}
   ins_pipe( pipe_slow );
 %}
 
+// encode char[] to byte[] in ASCII
+instruct encode_ascii_array(eSIRegP src, eDIRegP dst, eDXRegI len,
+                            regD tmp1, regD tmp2, regD tmp3, regD tmp4,
+                            eCXRegI tmp5, eAXRegI result, eFlagsReg cr) %{
+  predicate(((EncodeISOArrayNode*)n)->is_ascii());
+  match(Set result (EncodeISOArray src (Binary dst len)));
+  effect(TEMP tmp1, TEMP tmp2, TEMP tmp3, TEMP tmp4, USE_KILL src, USE_KILL dst, USE_KILL len, KILL tmp5, KILL cr);
+
+  format %{ "Encode ascii array $src,$dst,$len -> $result    // KILL ECX, EDX, $tmp1, $tmp2, $tmp3, $tmp4, ESI, EDI " %}
+  ins_encode %{
+    __ encode_iso_array($src$$Register, $dst$$Register, $len$$Register,
+                        $tmp1$$XMMRegister, $tmp2$$XMMRegister, $tmp3$$XMMRegister,
+                        $tmp4$$XMMRegister, $tmp5$$Register, $result$$Register, true);
+  %}
+  ins_pipe( pipe_slow );
+%}
 
 //----------Control Flow Instructions------------------------------------------
 // Signed compare Instructions

src/hotspot/cpu/x86/x86_64.ad

@@ -11770,14 +11770,32 @@ instruct string_inflate_evex(Universe dummy, rsi_RegP src, rdi_RegP dst, rdx_Reg
 instruct encode_iso_array(rsi_RegP src, rdi_RegP dst, rdx_RegI len,
                           legRegD tmp1, legRegD tmp2, legRegD tmp3, legRegD tmp4,
                           rcx_RegI tmp5, rax_RegI result, rFlagsReg cr) %{
+  predicate(!((EncodeISOArrayNode*)n)->is_ascii());
   match(Set result (EncodeISOArray src (Binary dst len)));
   effect(TEMP tmp1, TEMP tmp2, TEMP tmp3, TEMP tmp4, USE_KILL src, USE_KILL dst, USE_KILL len, KILL tmp5, KILL cr);
 
-  format %{ "Encode array $src,$dst,$len -> $result    // KILL RCX, RDX, $tmp1, $tmp2, $tmp3, $tmp4, RSI, RDI " %}
+  format %{ "Encode iso array $src,$dst,$len -> $result    // KILL RCX, RDX, $tmp1, $tmp2, $tmp3, $tmp4, RSI, RDI " %}
   ins_encode %{
     __ encode_iso_array($src$$Register, $dst$$Register, $len$$Register,
                         $tmp1$$XMMRegister, $tmp2$$XMMRegister, $tmp3$$XMMRegister,
-                        $tmp4$$XMMRegister, $tmp5$$Register, $result$$Register);
+                        $tmp4$$XMMRegister, $tmp5$$Register, $result$$Register, false);
+  %}
+  ins_pipe( pipe_slow );
+%}
+
+// encode char[] to byte[] in ASCII
+instruct encode_ascii_array(rsi_RegP src, rdi_RegP dst, rdx_RegI len,
+                            legRegD tmp1, legRegD tmp2, legRegD tmp3, legRegD tmp4,
+                            rcx_RegI tmp5, rax_RegI result, rFlagsReg cr) %{
+  predicate(((EncodeISOArrayNode*)n)->is_ascii());
+  match(Set result (EncodeISOArray src (Binary dst len)));
+  effect(TEMP tmp1, TEMP tmp2, TEMP tmp3, TEMP tmp4, USE_KILL src, USE_KILL dst, USE_KILL len, KILL tmp5, KILL cr);
+
+  format %{ "Encode ascii array $src,$dst,$len -> $result    // KILL RCX, RDX, $tmp1, $tmp2, $tmp3, $tmp4, RSI, RDI " %}
+  ins_encode %{
+    __ encode_iso_array($src$$Register, $dst$$Register, $len$$Register,
+                        $tmp1$$XMMRegister, $tmp2$$XMMRegister, $tmp3$$XMMRegister,
+                        $tmp4$$XMMRegister, $tmp5$$Register, $result$$Register, true);
   %}
   ins_pipe( pipe_slow );
 %}

src/hotspot/share/classfile/vmIntrinsics.cpp

@@ -505,6 +505,7 @@ bool vmIntrinsics::disabled_by_jvm_flags(vmIntrinsics::ID id) {
     if (!SpecialArraysEquals) return true;
     break;
   case vmIntrinsics::_encodeISOArray:
+  case vmIntrinsics::_encodeAsciiArray:
   case vmIntrinsics::_encodeByteISOArray:
     if (!SpecialEncodeISOArray) return true;
     break;

src/hotspot/share/classfile/vmIntrinsics.hpp

@@ -353,6 +353,9 @@ class methodHandle;
                                                                                                                         \
   do_intrinsic(_encodeByteISOArray,     java_lang_StringCoding, encodeISOArray_name, indexOfI_signature,         F_S)   \
                                                                                                                         \
+  do_intrinsic(_encodeAsciiArray,       java_lang_StringCoding, encodeAsciiArray_name, encodeISOArray_signature, F_S)   \
+   do_name(     encodeAsciiArray_name,                           "implEncodeAsciiArray")                                \
+                                                                                                                        \
   do_class(java_math_BigInteger,                      "java/math/BigInteger")                                           \
   do_intrinsic(_multiplyToLen,      java_math_BigInteger, multiplyToLen_name, multiplyToLen_signature, F_S)             \
    do_name(     multiplyToLen_name,                             "implMultiplyToLen")                                    \

src/hotspot/share/opto/c2compiler.cpp

@@ -216,6 +216,9 @@ bool C2Compiler::is_intrinsic_supported(const methodHandle& method, bool is_virt
   case vmIntrinsics::_copyMemory:
     if (StubRoutines::unsafe_arraycopy() == NULL) return false;
     break;
+  case vmIntrinsics::_encodeAsciiArray:
+    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;

src/hotspot/share/opto/intrinsicnode.hpp

@@ -168,10 +168,14 @@ class HasNegativesNode: public StrIntrinsicNode {
 
 
 //------------------------------EncodeISOArray--------------------------------
-// encode char[] to byte[] in ISO_8859_1
+// encode char[] to byte[] in ISO_8859_1 or ASCII
 class EncodeISOArrayNode: public Node {
+  bool ascii;
  public:
-  EncodeISOArrayNode(Node* control, Node* arymem, Node* s1, Node* s2, Node* c): Node(control, arymem, s1, s2, c) {};
+  EncodeISOArrayNode(Node* control, Node* arymem, Node* s1, Node* s2, Node* c, bool ascii)
+    : Node(control, arymem, s1, s2, c), ascii(ascii) {}
+
+  bool is_ascii() { return ascii; }
   virtual int Opcode() const;
   virtual bool depends_only_on_test() const { return false; }
   virtual const Type* bottom_type() const { return TypeInt::INT; }

src/hotspot/share/opto/library_call.cpp

@@ -591,7 +591,9 @@ bool LibraryCallKit::try_to_inline(int predicate) {
 
   case vmIntrinsics::_encodeISOArray:
   case vmIntrinsics::_encodeByteISOArray:
-    return inline_encodeISOArray();
+    return inline_encodeISOArray(false);
+  case vmIntrinsics::_encodeAsciiArray:
+    return inline_encodeISOArray(true);
 
   case vmIntrinsics::_updateCRC32:
     return inline_updateCRC32();
@@ -4882,8 +4884,8 @@ LibraryCallKit::tightly_coupled_allocation(Node* ptr) {
 }
 
 //-------------inline_encodeISOArray-----------------------------------
-// encode char[] to byte[] in ISO_8859_1
-bool LibraryCallKit::inline_encodeISOArray() {
+// encode char[] to byte[] in ISO_8859_1 or ASCII
+bool LibraryCallKit::inline_encodeISOArray(bool ascii) {
   assert(callee()->signature()->size() == 5, "encodeISOArray has 5 parameters");
   // no receiver since it is static method
   Node *src         = argument(0);
@@ -4918,7 +4920,7 @@ bool LibraryCallKit::inline_encodeISOArray() {
   // 'dst_start' points to dst array + scaled offset
 
   const TypeAryPtr* mtype = TypeAryPtr::BYTES;
-  Node* enc = new EncodeISOArrayNode(control(), memory(mtype), src_start, dst_start, length);
+  Node* enc = new EncodeISOArrayNode(control(), memory(mtype), src_start, dst_start, length, ascii);
   enc = _gvn.transform(enc);
   Node* res_mem = _gvn.transform(new SCMemProjNode(enc));
   set_memory(res_mem, mtype);

src/hotspot/share/opto/library_call.hpp

@@ -285,7 +285,7 @@ class LibraryCallKit : public GraphKit {
   Node* get_state_from_digest_object(Node *digestBase_object, const char* state_type);
   Node* get_digest_length_from_digest_object(Node *digestBase_object);
   Node* inline_digestBase_implCompressMB_predicate(int predicate);
-  bool inline_encodeISOArray();
+  bool inline_encodeISOArray(bool ascii);
   bool inline_updateCRC32();
   bool inline_updateBytesCRC32();
   bool inline_updateByteBufferCRC32();

src/java.base/share/classes/java/lang/StringCoding.java

@@ -46,7 +46,7 @@ public static boolean hasNegatives(byte[] ba, int off, int len) {
 
     @IntrinsicCandidate
     public static int implEncodeISOArray(byte[] sa, int sp,
-                                          byte[] da, int dp, int len) {
+                                         byte[] da, int dp, int len) {
         int i = 0;
         for (; i < len; i++) {
             char c = StringUTF16.getChar(sa, sp++);
@@ -57,4 +57,18 @@ public static int implEncodeISOArray(byte[] sa, int sp,
         return i;
     }
 
+    @IntrinsicCandidate
+    public static int implEncodeAsciiArray(char[] sa, int sp,
+                                           byte[] da, int dp, int len)
+    {
+        int i = 0;
+        for (; i < len; i++) {
+            char c = sa[sp++];
+            if (c >= '\u0080')
+                break;
+            da[dp++] = (byte)c;
+        }
+        return i;
+    }
+
 }

src/java.base/share/classes/java/lang/System.java

@@ -2419,6 +2419,10 @@ public int decodeASCII(byte[] src, int srcOff, char[] dst, int dstOff, int len)
                 return String.decodeASCII(src, srcOff, dst, dstOff, len);
             }
 
+            public int encodeASCII(char[] src, int srcOff, byte[] dst, int dstOff, int len) {
+                return StringCoding.implEncodeAsciiArray(src, srcOff, dst, dstOff, len);
+            }
+
             public void setCause(Throwable t, Throwable cause) {
                 t.setCause(cause);
             }

src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java

@@ -356,6 +356,15 @@ public interface JavaLangAccess {
      */
     int decodeASCII(byte[] src, int srcOff, char[] dst, int dstOff, int len);
 
+    /**
+     * Encodes ASCII codepoints as possible from the source array into
+     * the destination byte array, assuming that the encoding is ASCII
+     * compatible
+     *
+     * @return the number of bytes successfully encoded, or 0 if none
+     */
+    int encodeASCII(char[] src, int srcOff, byte[] dst, int dstOff, int len);
+
     /**
      * Set the cause of Throwable
      * @param cause set t's cause to new value