[GR-67840] Separate build time and runtime code alignment

PullRequest: graal/21683

Author: kittyoracle

substratevm/src/com.oracle.svm.core.foreign/src/com/oracle/svm/core/foreign/TrampolineSet.java

@@ -57,7 +57,7 @@ private static UnsignedWord allocationSize() {
     }
 
     private static UnsignedWord alignment() {
-        return Word.unsigned(SubstrateOptions.codeAlignment());
+        return Word.unsigned(SubstrateOptions.runtimeCodeAlignment());
     }
 
     private static int maxTrampolineCount() {
@@ -145,7 +145,7 @@ void patchTrampolineForDirectUpcall(Pointer trampolinePointer, CFunctionPointer
     private Pointer prepareTrampolines(PinnedObject mhsArray, PinnedObject stubsArray, AbiUtils.TrampolineTemplate template) {
         UnsignedWord pageSize = allocationSize();
         /* We request a specific alignment to guarantee correctness of getAllocationBase */
-        Pointer page = CommittedMemoryProvider.get().allocateExecutableMemory(pageSize, Word.unsigned(SubstrateOptions.codeAlignment()));
+        Pointer page = CommittedMemoryProvider.get().allocateExecutableMemory(pageSize, Word.unsigned(SubstrateOptions.runtimeCodeAlignment()));
         if (page.isNull()) {
             throw new OutOfMemoryError("Could not allocate memory for trampolines.");
         }

substratevm/src/com.oracle.svm.core.graal.aarch64/src/com/oracle/svm/core/graal/aarch64/SubstrateAArch64Backend.java

@@ -1335,7 +1335,7 @@ public CompilationResultBuilder newCompilationResultBuilder(LIRGenerationResult
         crb.setTotalFrameSize(lirGenResult.getFrameMap().totalFrameSize());
         if (SubstrateUtil.HOSTED) {
             var sharedCompilationResult = (SharedCompilationResult) compilationResult;
-            sharedCompilationResult.setCodeAlignment(SubstrateOptions.codeAlignment(options));
+            sharedCompilationResult.setCodeAlignment(SubstrateOptions.buildTimeCodeAlignment(options));
         }
         return crb;
     }

substratevm/src/com.oracle.svm.core.graal.amd64/src/com/oracle/svm/core/graal/amd64/SubstrateAMD64Backend.java

@@ -1902,7 +1902,7 @@ public CompilationResultBuilder newCompilationResultBuilder(LIRGenerationResult
         var substrateAMD64FrameMap = (SubstrateAMD64FrameMap) frameMap;
         sharedCompilationResult.setFrameSize(substrateAMD64FrameMap.frameSize());
         if (SubstrateUtil.HOSTED) {
-            sharedCompilationResult.setCodeAlignment(SubstrateOptions.codeAlignment(options));
+            sharedCompilationResult.setCodeAlignment(SubstrateOptions.buildTimeCodeAlignment(options));
         }
         if (substrateAMD64FrameMap.needsFramePointer()) {
             sharedCompilationResult.setFramePointerSaveAreaOffset(substrateAMD64FrameMap.getFramePointerSaveAreaOffset());

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/SubstrateOptions.java

@@ -1031,27 +1031,41 @@ public static boolean useLIRBackend() {
     public static final HostedOptionKey<Boolean> DeadlockWatchdogExitOnTimeout = new HostedOptionKey<>(true);
 
     /**
-     * The alignment for AOT and JIT compiled methods. The value is constant folded during image
-     * generation, i.e., cannot be changed at run time, so that it can be used in uninterruptible
-     * code.
+     * The alignment for JIT compiled methods.
      */
     @Fold
-    public static int codeAlignment() {
+    public static int runtimeCodeAlignment() {
+        int value = ConcealedOptions.CodeAlignment.getValue();
+        // In runtime compiled methods, data is also aligned according to the return value of this
+        // method. As a result, it needs to be at least defaultCodeAlignment() so that it can
+        // support the allocation of large constants such as SIMD ones.
+        return Math.max(value, defaultCodeAlignment());
+    }
+
+    /**
+     * The alignment for AOT compiled methods.
+     */
+    @Platforms(Platform.HOSTED_ONLY.class)
+    public static int buildTimeCodeAlignment() {
         int value = ConcealedOptions.CodeAlignment.getValue();
         if (value > 0) {
+            // In contrast to runtimeCodeAlignment, this value can be less than
+            // defaultCodeAlignment() so that methods can be more densely packed in the generated
+            // native image.
             return value;
         }
 
-        if (ConfigurationValues.getTarget().arch instanceof AMD64) {
-            return 32;
-        }
-        return 16;
+        return defaultCodeAlignment();
+    }
+
+    private static int defaultCodeAlignment() {
+        return ConfigurationValues.getTarget().arch instanceof AMD64 ? 32 : 16;
     }
 
     @Platforms(Platform.HOSTED_ONLY.class)
-    public static int codeAlignment(OptionValues options) {
+    public static int buildTimeCodeAlignment(OptionValues options) {
         int value = ConcealedOptions.CodeAlignment.getValue(options);
-        return value > 0 ? value : codeAlignment();
+        return value > 0 ? value : buildTimeCodeAlignment();
     }
 
     @Option(help = "Determines if VM internal threads (e.g., a dedicated VM operation or reference handling thread) are allowed in this image.", type = OptionType.Expert) //
@@ -1236,7 +1250,10 @@ protected void onValueUpdate(EconomicMap<OptionKey<?>, Object> values, Integer o
         @Option(help = "Generated code style for prefetch instructions: for 0 or less no prefetch instructions are generated and for 1 or more prefetch instructions are introduced after each allocation.")//
         public static final HostedOptionKey<Integer> AllocatePrefetchStyle = new HostedOptionKey<>(null);
 
-        /** Use {@link SubstrateOptions#codeAlignment()} instead. */
+        /**
+         * Use {@link SubstrateOptions#buildTimeCodeAlignment()} or
+         * {@link SubstrateOptions#runtimeCodeAlignment()} instead.
+         */
         @LayerVerifiedOption(kind = Kind.Changed, severity = Severity.Error)//
         @Option(help = "Alignment of AOT and JIT compiled code in bytes. The default of 0 automatically selects a suitable value.")//
         public static final HostedOptionKey<Integer> CodeAlignment = new HostedOptionKey<>(0);

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/code/RuntimeCodeInfoAccess.java

@@ -218,12 +218,12 @@ static void markAsRemovedFromCodeCache(CodeInfo info) {
     }
 
     public static CodePointer allocateCodeMemory(UnsignedWord size) {
-        return (CodePointer) CommittedMemoryProvider.get().allocateExecutableMemory(size, Word.unsigned(SubstrateOptions.codeAlignment()));
+        return (CodePointer) CommittedMemoryProvider.get().allocateExecutableMemory(size, Word.unsigned(SubstrateOptions.runtimeCodeAlignment()));
     }
 
     @Uninterruptible(reason = "Called from uninterruptible code.", mayBeInlined = true)
     private static void releaseCodeMemory(CodePointer codeStart, UnsignedWord codeSize) {
-        CommittedMemoryProvider.get().freeExecutableMemory(codeStart, codeSize, Word.unsigned(SubstrateOptions.codeAlignment()));
+        CommittedMemoryProvider.get().freeExecutableMemory(codeStart, codeSize, Word.unsigned(SubstrateOptions.runtimeCodeAlignment()));
     }
 
     public static void makeCodeMemoryExecutableReadOnly(CodePointer codeStart, UnsignedWord codeSize) {

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/code/SharedCompilationResult.java

@@ -29,6 +29,8 @@
 import jdk.graal.compiler.code.CompilationResult;
 import jdk.graal.compiler.core.common.CompilationIdentifier;
 import jdk.graal.compiler.core.common.NumUtil;
+import org.graalvm.nativeimage.Platform;
+import org.graalvm.nativeimage.Platforms;
 
 /** Base class common to both hosted and runtime compilations. */
 public abstract class SharedCompilationResult extends CompilationResult {
@@ -64,17 +66,19 @@ public void setFramePointerSaveAreaOffset(int value) {
         this.framePointerSaveAreaOffset = value;
     }
 
+    @Platforms(Platform.HOSTED_ONLY.class)
     public static int getCodeAlignment(CompilationResult compilation) {
         int result;
         if (compilation instanceof SharedCompilationResult s) {
             result = s.codeAlignment;
         } else {
-            result = SubstrateOptions.codeAlignment();
+            result = SubstrateOptions.buildTimeCodeAlignment();
         }
         VMError.guarantee(result > 0 && NumUtil.isUnsignedPowerOf2(result), "invalid alignment %d", result);
         return result;
     }
 
+    @Platforms(Platform.HOSTED_ONLY.class)
     public void setCodeAlignment(int codeAlignment) {
         VMError.guarantee(codeAlignment > 0 && NumUtil.isUnsignedPowerOf2(codeAlignment), "invalid alignment %d", codeAlignment);
         this.codeAlignment = codeAlignment;

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/graal/code/SubstrateDataBuilder.java

@@ -102,6 +102,6 @@ public static void emit(ByteBuffer buffer, Patches patches, int size, VMConstant
     public int getMaxSupportedAlignment() {
         // See RuntimeCodeInstaller.prepareCodeMemory
         // Code and data are allocated in one go
-        return SubstrateOptions.codeAlignment();
+        return SubstrateOptions.runtimeCodeAlignment();
     }
 }

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/image/LIRNativeImageCodeCache.java

@@ -194,7 +194,7 @@ public void layoutMethods(DebugContext debug, BigBang bb) {
             Pair<HostedMethod, CompilationResult> lastCompilation = getLastCompilation();
             HostedMethod lastMethod = lastCompilation.getLeft();
 
-            // the total code size is aligned up to SubstrateOptions.codeAlignment()
+            // the total code size is aligned up to SubstrateOptions.buildTimeCodeAlignment()
             int totalSize;
             if (orderedTrampolineMap.containsKey(lastMethod)) {
                 var trampolines = orderedTrampolineMap.get(lastMethod);
@@ -203,7 +203,7 @@ public void layoutMethods(DebugContext debug, BigBang bb) {
             } else {
                 totalSize = addOffset(lastCompilation.getLeft().getCodeAddressOffset(), lastCompilation.getRight().getTargetCodeSize());
             }
-            totalSize = align(totalSize, SubstrateOptions.codeAlignment());
+            totalSize = align(totalSize, SubstrateOptions.buildTimeCodeAlignment());
 
             setCodeAreaSize(totalSize);
 
@@ -476,7 +476,7 @@ public void writeCode(RelocatableBuffer buffer) {
                 }
             }
 
-            for (int i = curPos; i < NumUtil.roundUp(curPos, SubstrateOptions.codeAlignment()); i++) {
+            for (int i = curPos; i < NumUtil.roundUp(curPos, SubstrateOptions.buildTimeCodeAlignment()); i++) {
                 bufferBytes.put(CODE_FILLER_BYTE);
             }
         }