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changeset 11825:463f51256c86

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AMD64HotSpot: emit jump to IC miss handler directly instead of emitting it inside verfied_entry for empty methods we emitted something like this if a inline cache is needed: prefix: 00: < IC check > ... 0b: jne <ic_miss_call> 11: nop ... verified_entry: 20: ret ic_miss_call: 21: jmp <entry of runtime function> when a method is deoptimized, HotSpot patches the verified_entry (0x20) with a jump to a stub that handles call-sites that has been made non-entrant. since this jump is 5 bytes long, it will overwrite ic_miss_call and blow up every caller that calls this method via the unverified entry (prefix). the fix is to emit the jump to the runtime function inside the unverfied entry: prefix: 00: < IC check > ... 0b: je <verified_entry> 11: jeq <entry of runtime function> 16: nop ... verified_entry: 20: ret
author Bernhard Urban <bernhard.urban@jku.at>
date Mon, 30 Sep 2013 09:32:18 +0200
parents e1a1264cb0a7
children 2d3d3d36ab3c
files graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotBackend.java
diffstat 1 files changed, 5 insertions(+), 9 deletions(-) [+]
line wrap: on
line diff
--- a/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotBackend.java	Mon Sep 30 09:47:41 2013 +0200
+++ b/graal/com.oracle.graal.hotspot.amd64/src/com/oracle/graal/hotspot/amd64/AMD64HotSpotBackend.java	Mon Sep 30 09:32:18 2013 +0200
@@ -236,11 +236,10 @@
         FrameMap frameMap = tasm.frameMap;
         RegisterConfig regConfig = frameMap.registerConfig;
         HotSpotVMConfig config = runtime().config;
-        Label unverifiedStub = installedCodeOwner == null || isStatic(installedCodeOwner.getModifiers()) ? null : new Label();
+        Label verifiedStub = new Label();
 
         // Emit the prefix
-
-        if (unverifiedStub != null) {
+        if (installedCodeOwner != null && !isStatic(installedCodeOwner.getModifiers())) {
             tasm.recordMark(Marks.MARK_UNVERIFIED_ENTRY);
             CallingConvention cc = regConfig.getCallingConvention(JavaCallee, null, new JavaType[]{runtime().lookupJavaType(Object.class)}, target, false);
             Register inlineCacheKlass = rax; // see definition of IC_Klass in
@@ -257,11 +256,13 @@
             } else {
                 asm.cmpq(inlineCacheKlass, src);
             }
-            asm.jcc(ConditionFlag.NotEqual, unverifiedStub);
+            asm.jcc(ConditionFlag.Equal, verifiedStub);
+            AMD64Call.directJmp(tasm, asm, runtime().lookupForeignCall(IC_MISS_HANDLER));
         }
 
         asm.align(config.codeEntryAlignment);
         tasm.recordMark(Marks.MARK_OSR_ENTRY);
+        asm.bind(verifiedStub);
         tasm.recordMark(Marks.MARK_VERIFIED_ENTRY);
 
         // Emit code for the LIR
@@ -278,10 +279,5 @@
             // it has no calls that can cause such "return" entries
             assert !frameMap.accessesCallerFrame() : lirGen.getGraph();
         }
-
-        if (unverifiedStub != null) {
-            asm.bind(unverifiedStub);
-            AMD64Call.directJmp(tasm, asm, runtime().lookupForeignCall(IC_MISS_HANDLER));
-        }
     }
 }