Adjust inline cache check size for forced 4-byte displacements

roberttoyonaga · Mar 7, 2024 · c7abc29 · c7abc29
1 parent 8433868
commit c7abc29
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Showing 2 changed files with 19 additions and 4 deletions.
diff --git a/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/asm/amd64/AMD64BaseAssembler.java b/compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/asm/amd64/AMD64BaseAssembler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2024, 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
@@ -50,6 +50,8 @@
 import static jdk.vm.ci.amd64.AMD64.rbp;
 import static jdk.vm.ci.amd64.AMD64.rsp;
 
+import java.util.EnumSet;
+
 import org.graalvm.collections.EconomicSet;
 
 import jdk.graal.compiler.asm.Assembler;
@@ -63,8 +65,6 @@
 import jdk.vm.ci.code.TargetDescription;
 import jdk.vm.ci.meta.PlatformKind;
 
-import java.util.EnumSet;
-
 /**
  * This class implements an assembler that can encode most X86 instructions.
  */
@@ -285,6 +285,14 @@ public void setForce4ByteNonZeroDisplacements(boolean force4ByteNonZeroDisplacem
         this.force4ByteNonZeroDisplacements = force4ByteNonZeroDisplacements;
     }
 
+    /**
+     * Returns {@code true}} if this assembler is configured to emit all non-zero displacements in
+     * addresses as 4 bytes even if they would fit into a byte.
+     */
+    public boolean force4ByteNonZeroDisplacements() {
+        return force4ByteNonZeroDisplacements;
+    }
+
     protected void annotatePatchingImmediate(int operandOffset, int operandSize) {
         if (codePatchingAnnotationConsumer != null) {
             int pos = position();

diff --git a/...iler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/amd64/AMD64HotSpotBackend.java b/...iler/src/jdk.graal.compiler/src/jdk/graal/compiler/hotspot/amd64/AMD64HotSpotBackend.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2012, 2024, 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
@@ -360,6 +360,13 @@ public void emitCodePrefix(ResolvedJavaMethod installedCodeOwner, CompilationRes
 
                 // Size of IC check sequence checked with a guarantee below.
                 int inlineCacheCheckSize = 14;
+                if (asm.force4ByteNonZeroDisplacements()) {
+                    /*
+                     * The mov and cmp below each contain a 1-byte displacement that is emitted as 4
+                     * bytes instead, thus we have 3 extra bytes for each of these instructions.
+                     */
+                    inlineCacheCheckSize += 3 + 3;
+                }
                 asm.align(config.codeEntryAlignment, asm.position() + inlineCacheCheckSize);
 
                 int startICCheck = asm.position();