Merge to tag jdk-27+18

bin/idea.sh

@@ -187,14 +187,18 @@ fi
 SOURCE_PREFIX="<sourceFolder url=\"file://"
 SOURCE_POSTFIX="\" isTestSource=\"false\" />"
 
+# SOURCES is a single string containing embeded newlines.
 for root in $MODULE_ROOTS; do
     if [ "x$CYGPATH" != "x" ]; then
       root=`$CYGPATH -am $root`
     elif [ "x$WSL_DISTRO_NAME" != "x" ]; then
       root=`wslpath -am $root`
     fi
-
-    SOURCES=$SOURCES" $SOURCE_PREFIX""$root""$SOURCE_POSTFIX"
+    # Add line termination/indentation for everything after the first entry.
+    if [ "x$SOURCES" != "x" ]; then
+      SOURCES="${SOURCES}\n      "
+    fi
+    SOURCES="${SOURCES}${SOURCE_PREFIX}${root}${SOURCE_POSTFIX}"
 done
 
 add_replacement "###SOURCE_ROOTS###" "$SOURCES"

make/Hsdis.gmk

@@ -44,6 +44,9 @@ ifeq ($(HSDIS_BACKEND), capstone)
   else ifeq ($(call isTargetCpuArch, aarch64), true)
     CAPSTONE_ARCH := CS_ARCH_$(CAPSTONE_ARCH_AARCH64_NAME)
     CAPSTONE_MODE := CS_MODE_ARM
+  else ifeq ($(call isTargetCpuArch, arm), true)
+    CAPSTONE_ARCH := CS_ARCH_ARM
+    CAPSTONE_MODE := CS_MODE_ARM
   else
     $(error No support for Capstone on this platform)
   endif

make/autoconf/flags-cflags.m4

@@ -544,12 +544,9 @@ AC_DEFUN([FLAGS_SETUP_CFLAGS_HELPER],
     TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM -fstack-protector"
     TOOLCHAIN_CFLAGS_JDK="-fvisibility=hidden -pipe -fstack-protector"
     # reduce lib size on linux in link step, this needs also special compile flags
-    # do this on s390x also for libjvm (where serviceability agent is not supported)
     if test "x$ENABLE_LINKTIME_GC" = xtrue; then
       TOOLCHAIN_CFLAGS_JDK="$TOOLCHAIN_CFLAGS_JDK -ffunction-sections -fdata-sections"
-      if test "x$OPENJDK_TARGET_CPU" = xs390x && test "x$DEBUG_LEVEL" == xrelease; then
-        TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM -ffunction-sections -fdata-sections"
-      fi
+      TOOLCHAIN_CFLAGS_JVM="$TOOLCHAIN_CFLAGS_JVM -ffunction-sections -fdata-sections"
     fi
     # technically NOT for CXX (but since this gives *worse* performance, use
     # no-strict-aliasing everywhere!)

make/autoconf/flags-ldflags.m4

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2026, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -53,16 +53,15 @@ AC_DEFUN([FLAGS_SETUP_LDFLAGS_HELPER],
     # add --icf=all (Identical Code Folding — merges identical functions)
     BASIC_LDFLAGS="-Wl,-z,defs -Wl,-z,relro -Wl,-z,now -Wl,--no-as-needed -Wl,--exclude-libs,ALL"
 
+    BASIC_LDFLAGS_JVM_ONLY=""
     # Linux : remove unused code+data in link step
     if test "x$ENABLE_LINKTIME_GC" = xtrue; then
-      if test "x$OPENJDK_TARGET_CPU" = xs390x; then
-        BASIC_LDFLAGS="$BASIC_LDFLAGS -Wl,--gc-sections"
-      else
-        BASIC_LDFLAGS_JDK_ONLY="$BASIC_LDFLAGS_JDK_ONLY -Wl,--gc-sections"
-      fi
+      # keep vtables : -Wl,--undefined-glob=_ZTV* (but this seems not to work with gold ld)
+      # so keep at least the Metadata vtable that is used in the serviceability agent
+      BASIC_LDFLAGS_JVM_ONLY="$BASIC_LDFLAGS_JVM_ONLY -Wl,--gc-sections -Wl,--undefined=_ZTV8Metadata"
+      BASIC_LDFLAGS_JDK_ONLY="$BASIC_LDFLAGS_JDK_ONLY -Wl,--gc-sections"
     fi
 
-    BASIC_LDFLAGS_JVM_ONLY=""
     LDFLAGS_LTO="-flto=auto -fuse-linker-plugin -fno-strict-aliasing $DEBUG_PREFIX_CFLAGS"
 
     LDFLAGS_CXX_PARTIAL_LINKING="$MACHINE_FLAG -r"

make/jdk/src/classes/build/tools/cldrconverter/CLDRConverter.java

@@ -801,10 +801,7 @@ private static Map<String, Object> extractZoneNames(Map<String, Object> map, Str
             String tzKey = Optional.ofNullable((String)handlerSupplMeta.get(tzid))
                                    .orElse(tzid);
             // Follow link, if needed
-            String tzLink = null;
-            for (var k = tzKey; tzdbLinks.containsKey(k);) {
-                k = tzLink = tzdbLinks.get(k);
-            }
+            String tzLink = getTZDBLink(tzKey);
             if (tzLink == null && tzdbLinks.containsValue(tzKey)) {
                 // reverse link search
                 // this is needed as in tzdb, "America/Buenos_Aires" links to
@@ -833,7 +830,7 @@ private static Map<String, Object> extractZoneNames(Map<String, Object> map, Str
                 } else {
                     // TZDB short names
                     tznames = Arrays.copyOf(tznames, tznames.length);
-                    fillTZDBShortNames(tzid, tznames);
+                    fillTZDBShortNames(tzKey, tznames);
                     names.put(tzid, tznames);
                 }
             } else {
@@ -846,11 +843,13 @@ private static Map<String, Object> extractZoneNames(Map<String, Object> map, Str
                     String metaKey = METAZONE_ID_PREFIX + meta;
                     data = map.get(metaKey);
                     if (data instanceof String[] tznames) {
-                        // TZDB short names
-                        tznames = Arrays.copyOf((String[])names.getOrDefault(metaKey, tznames), 6);
-                        fillTZDBShortNames(tzid, tznames);
-                        // Keep the metazone prefix here.
-                        names.putIfAbsent(metaKey, tznames);
+                        if (isDefaultZone(meta, tzKey)) {
+                            // Record the metazone names only from the default
+                            // (001) zone, with short names filled from TZDB
+                            tznames = Arrays.copyOf(tznames, tznames.length);
+                            fillTZDBShortNames(tzKey, tznames);
+                            names.put(metaKey, tznames);
+                        }
                         names.put(tzid, meta);
                         if (tzLink != null && availableIds.contains(tzLink)) {
                             names.put(tzLink, meta);
@@ -1504,12 +1503,12 @@ private static String flipIfNeeded(boolean inVanguard, String format) {
      * Fill the TZDB short names if there is no name provided by the CLDR
      */
     private static void fillTZDBShortNames(String tzid, String[] names) {
-        var val = tzdbShortNamesMap.get(tzdbLinks.getOrDefault(tzid, tzid));
+        var val = tzdbShortNamesMap.getOrDefault(tzid, tzdbShortNamesMap.get(getTZDBLink(tzid)));
         if (val != null) {
             var format = val.split(NBSP)[0];
             var rule = val.split(NBSP)[1];
             IntStream.of(1, 3, 5).forEach(i -> {
-                if (names[i] == null) {
+                if (names[i] == null || names[i].isEmpty()) {
                     if (format.contains("%s")) {
                         names[i] = switch (i) {
                             case 1 -> format.formatted(tzdbSubstLetters.get(rule + NBSP + STD));
@@ -1531,6 +1530,21 @@ private static void fillTZDBShortNames(String tzid, String[] names) {
         }
     }
 
+    private static boolean isDefaultZone(String meta, String tzid) {
+        String zone001 = handlerMetaZones.zidMap().get(meta);
+        var tzLink = getTZDBLink(tzid);
+        return canonicalTZMap.getOrDefault(tzid, tzid).equals(zone001) ||
+            tzLink != null && canonicalTZMap.getOrDefault(tzLink, tzLink).equals(zone001);
+    }
+
+    private static String getTZDBLink(String tzid) {
+        String tzLink = null;
+        for (var k = tzid; tzdbLinks.containsKey(k);) {
+            k = tzLink = tzdbLinks.get(k);
+        }
+        return tzLink;
+    }
+
     /*
      * Convert TZDB offsets to JDK's offsets, eg, "-08" to "GMT-08:00".
      * If it cannot recognize the pattern, return the argument as is.

make/modules/jdk.hotspot.agent/Lib.gmk

@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2015, 2025, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2015, 2026, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -55,6 +55,12 @@ else
   LIBSAPROC_LINK_TYPE := C
 endif
 
+# DWARF related sources would be included on supported platforms only.
+LIBSAPROC_EXCLUDE_FILES :=
+ifneq ($(call And, $(call isTargetOs, linux) $(call isTargetCpu, x86_64 aarch64)), true)
+  LIBSAPROC_EXCLUDE_FILES := DwarfParser.cpp dwarf.cpp
+endif
+
 $(eval $(call SetupJdkLibrary, BUILD_LIBSAPROC, \
     NAME := saproc, \
     LINK_TYPE := $(LIBSAPROC_LINK_TYPE), \
@@ -70,6 +76,7 @@ $(eval $(call SetupJdkLibrary, BUILD_LIBSAPROC, \
     CFLAGS := $(LIBSAPROC_CFLAGS), \
     CXXFLAGS := $(LIBSAPROC_CFLAGS) $(LIBSAPROC_CXXFLAGS), \
     EXTRA_SRC := $(LIBSAPROC_EXTRA_SRC), \
+    EXCLUDE_FILES := $(LIBSAPROC_EXCLUDE_FILES), \
     JDK_LIBS := java.base:libjava, \
     LIBS_linux := $(LIBDL), \
     LIBS_macosx := \

src/hotspot/cpu/aarch64/aarch64_vector.ad

@@ -1,6 +1,6 @@
 //
 // Copyright (c) 2020, 2026, Oracle and/or its affiliates. All rights reserved.
-// Copyright (c) 2020, 2025, Arm Limited. All rights reserved.
+// Copyright (c) 2020, 2026, Arm Limited. All rights reserved.
 // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 //
 // This code is free software; you can redistribute it and/or modify it
@@ -247,10 +247,39 @@ source %{
       case Op_MinVHF:
       case Op_MaxVHF:
       case Op_SqrtVHF:
+        if (UseSVE == 0 && !is_feat_fp16_supported()) {
+          return false;
+        }
+        break;
+      // At the time of writing this, the Vector API has no half-float (FP16) species.
+      // Consequently, AddReductionVHF and MulReductionVHF are only produced by the
+      // auto-vectorizer, which requires strictly ordered semantics for FP reductions.
+      //
+      // There is no direct Neon instruction that performs strictly ordered floating
+      // point add reduction. Hence, on Neon only machines, the add reduction operation
+      // is implemented as a scalarized sequence using half-precision scalar instruction
+      // FADD which requires FEAT_FP16 and ASIMDHP to be available on the target.
+      // On SVE machines (UseSVE > 0) however, there is a direct instruction (FADDA) which
+      // implements strictly ordered floating point add reduction which does not require
+      // the FEAT_FP16 and ASIMDHP checks as SVE supports half-precision floats by default.
+      case Op_AddReductionVHF:
         // FEAT_FP16 is enabled if both "fphp" and "asimdhp" features are supported.
         // Only the Neon instructions need this check. SVE supports half-precision floats
         // by default.
-        if (UseSVE == 0 && !is_feat_fp16_supported()) {
+        if (length_in_bytes < 8 || (UseSVE == 0 && !is_feat_fp16_supported())) {
+          return false;
+        }
+        break;
+      case Op_MulReductionVHF:
+        // There are no direct Neon/SVE instructions that perform strictly ordered
+        // floating point multiply reduction.
+        // For vector length ≤ 16 bytes, the reduction is implemented as a scalarized
+        // sequence using half-precision scalar instruction FMUL. This path requires
+        // FEAT_FP16 and ASIMDHP to be available on the target.
+        // For vector length > 16 bytes, this operation is disabled because there is no
+        // direct SVE instruction that performs a strictly ordered FP16 multiply
+        // reduction.
+        if (length_in_bytes < 8 || length_in_bytes > 16 || !is_feat_fp16_supported()) {
           return false;
         }
         break;
@@ -300,6 +329,7 @@ source %{
       case Op_VectorRearrange:
       case Op_MulReductionVD:
       case Op_MulReductionVF:
+      case Op_MulReductionVHF:
       case Op_MulReductionVI:
       case Op_MulReductionVL:
       case Op_CompressBitsV:
@@ -364,6 +394,7 @@ source %{
       case Op_VectorMaskCmp:
       case Op_LoadVectorGather:
       case Op_StoreVectorScatter:
+      case Op_AddReductionVHF:
       case Op_AddReductionVF:
       case Op_AddReductionVD:
       case Op_AndReductionV:
@@ -597,13 +628,9 @@ instruct vloadcon(vReg dst, immI0 src) %{
     BasicType bt = Matcher::vector_element_basic_type(this);
     if (UseSVE == 0) {
       uint length_in_bytes = Matcher::vector_length_in_bytes(this);
+      int entry_idx = __ vector_iota_entry_index(bt);
       assert(length_in_bytes <= 16, "must be");
-      // The iota indices are ordered by type B/S/I/L/F/D, and the offset between two types is 16.
-      int offset = exact_log2(type2aelembytes(bt)) << 4;
-      if (is_floating_point_type(bt)) {
-        offset += 32;
-      }
-      __ lea(rscratch1, ExternalAddress(StubRoutines::aarch64::vector_iota_indices() + offset));
+      __ lea(rscratch1, ExternalAddress(StubRoutines::aarch64::vector_iota_indices(entry_idx)));
       if (length_in_bytes == 16) {
         __ ldrq($dst$$FloatRegister, rscratch1);
       } else {
@@ -3406,6 +3433,44 @@ instruct reduce_non_strict_order_add4F_neon(vRegF dst, vRegF fsrc, vReg vsrc, vR
   ins_pipe(pipe_slow);
 %}
 
+// Add Reduction for Half floats (FP16).
+// Neon does not provide direct instructions for strictly ordered floating-point add reductions.
+// On Neon-only targets (UseSVE = 0), this operation is implemented as a sequence of scalar additions:
+// values equal to the vector width are loaded into a vector register, each lane is extracted,
+// and its value is accumulated into the running sum, producing a final scalar result.
+instruct reduce_addHF_neon(vRegF dst, vRegF fsrc, vReg vsrc, vReg tmp) %{
+  predicate(UseSVE == 0);
+  match(Set dst (AddReductionVHF fsrc vsrc));
+  effect(TEMP_DEF dst, TEMP tmp);
+  format %{ "reduce_addHF $dst, $fsrc, $vsrc\t# 4HF/8HF. KILL $tmp" %}
+  ins_encode %{
+    uint length_in_bytes = Matcher::vector_length_in_bytes(this, $vsrc);
+    __ neon_reduce_add_fp16($dst$$FloatRegister, $fsrc$$FloatRegister,
+                            $vsrc$$FloatRegister, length_in_bytes, $tmp$$FloatRegister);
+  %}
+  ins_pipe(pipe_slow);
+%}
+
+// This rule calculates the reduction result in strict order. Two cases will
+// reach here:
+// 1. Non strictly-ordered AddReductionVHF when vector size > 128-bits. For example -
+//    AddReductionVHF generated by Vector API. For vector size > 128-bits, it is more
+//    beneficial performance-wise to generate direct SVE instruction even if it is
+//    strictly ordered.
+// 2. Strictly-ordered AddReductionVHF. For example - AddReductionVHF generated by
+//    auto-vectorization on SVE machine.
+instruct reduce_addHF_sve(vRegF dst_src1, vReg src2) %{
+  predicate(UseSVE > 0);
+  match(Set dst_src1 (AddReductionVHF dst_src1 src2));
+  format %{ "reduce_addHF_sve $dst_src1, $dst_src1, $src2" %}
+  ins_encode %{
+    uint length_in_bytes = Matcher::vector_length_in_bytes(this, $src2);
+    assert(length_in_bytes == MaxVectorSize, "invalid vector length");
+    __ sve_fadda($dst_src1$$FloatRegister, __ H, ptrue, $src2$$FloatRegister);
+  %}
+  ins_pipe(pipe_slow);
+%}
+
 // This rule calculates the reduction result in strict order. Two cases will
 // reach here:
 // 1. Non strictly-ordered AddReductionVF when vector size > 128-bits. For example -
@@ -3496,12 +3561,14 @@ instruct reduce_addL_masked(iRegLNoSp dst, iRegL isrc, vReg vsrc, pRegGov pg, vR
   ins_pipe(pipe_slow);
 %}
 
-instruct reduce_addF_masked(vRegF dst_src1, vReg src2, pRegGov pg) %{
+instruct reduce_addFHF_masked(vRegF dst_src1, vReg src2, pRegGov pg) %{
   predicate(UseSVE > 0);
+  match(Set dst_src1 (AddReductionVHF (Binary dst_src1 src2) pg));
   match(Set dst_src1 (AddReductionVF (Binary dst_src1 src2) pg));
-  format %{ "reduce_addF_masked $dst_src1, $pg, $dst_src1, $src2" %}
+  format %{ "reduce_addFHF_masked $dst_src1, $pg, $dst_src1, $src2" %}
   ins_encode %{
-    __ sve_fadda($dst_src1$$FloatRegister, __ S,
+    BasicType bt = Matcher::vector_element_basic_type(this, $src2);
+    __ sve_fadda($dst_src1$$FloatRegister, __ elemType_to_regVariant(bt),
                  $pg$$PRegister, $src2$$FloatRegister);
   %}
   ins_pipe(pipe_slow);
@@ -3549,14 +3616,17 @@ instruct reduce_mulL(iRegLNoSp dst, iRegL isrc, vReg vsrc) %{
   ins_pipe(pipe_slow);
 %}
 
-instruct reduce_mulF(vRegF dst, vRegF fsrc, vReg vsrc, vReg tmp) %{
+
+instruct reduce_mulFHF(vRegF dst, vRegF fsrc, vReg vsrc, vReg tmp) %{
   predicate(Matcher::vector_length_in_bytes(n->in(2)) <= 16);
+  match(Set dst (MulReductionVHF fsrc vsrc));
   match(Set dst (MulReductionVF fsrc vsrc));
   effect(TEMP_DEF dst, TEMP tmp);
-  format %{ "reduce_mulF $dst, $fsrc, $vsrc\t# 2F/4F. KILL $tmp" %}
+  format %{ "reduce_mulFHF $dst, $fsrc, $vsrc\t# 2F/4F/4HF/8HF. KILL $tmp" %}
   ins_encode %{
     uint length_in_bytes = Matcher::vector_length_in_bytes(this, $vsrc);
-    __ neon_reduce_mul_fp($dst$$FloatRegister, T_FLOAT, $fsrc$$FloatRegister,
+    BasicType bt = Matcher::vector_element_basic_type(this, $vsrc);
+    __ neon_reduce_mul_fp($dst$$FloatRegister, bt, $fsrc$$FloatRegister,
                           $vsrc$$FloatRegister, length_in_bytes, $tmp$$FloatRegister);
   %}
   ins_pipe(pipe_slow);