[PATCH] GPU Exploitation Infrastructure

Ben Walsh ben_walsh at uk.ibm.com
Thu Feb 1 14:01:23 UTC 2018


As per the responses to 
http://mail.openjdk.java.net/pipermail/core-libs-dev/2018-January/051181.html
, I am reposting this patch to this mailing list ...

This patch provides the infrastructure to enable the exploitation of a GPU 
by the compiler to accelerate certain suitable Java constructs.

When enabled, a suitable compiler can attempt to accelerate the following 
Java constructs by launching the corresponding lambda expression on the 
GPU:

   IntStream.range(<range>).parallel().forEach(<lambda>)
   IntStream.rangeClosed(<range>).parallel().forEach(<lambda>)

   where:

      <range> defines upper and lower bounds
      <lambda> is a correctly defined lambda expression

As it stands, with the HotSpot compiler, this patch performs a "no op" in 
the newly added in-built native library method.
This can be extended so that the HotSpot compiler attempts the 
acceleration detailed above instead.

I would like to pair with a sponsor to contribute this patch ...


--------------------------------------------------------------------------------------------------------------

diff -r fd237da7a113 make/hotspot/symbols/symbols-unix
--- a/make/hotspot/symbols/symbols-unix Mon Jan 22 23:06:29 2018 -0800
+++ b/make/hotspot/symbols/symbols-unix Tue Jan 30 10:07:18 2018 +0000
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2016, 2017, Oracle and/or its affiliates. All rights 
reserved.
+# Copyright (c) 2016, 2018, 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
@@ -187,3 +187,6 @@
 JVM_AddReadsModule
 JVM_DefineModule
 JVM_SetBootLoaderUnnamedModule
+
+# GPU exploitation support
+Java_java_util_stream_IntPipeline_promoteGPUCompile
diff -r fd237da7a113 src/hotspot/share/include/jvm.h
--- a/src/hotspot/share/include/jvm.h   Mon Jan 22 23:06:29 2018 -0800
+++ b/src/hotspot/share/include/jvm.h   Tue Jan 30 10:07:18 2018 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights 
reserved.
+ * Copyright (c) 1997, 2018, 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
@@ -1189,6 +1189,12 @@
 JNIEXPORT jstring JNICALL
 JVM_GetTemporaryDirectory(JNIEnv *env);
 
+/*
+ * GPU exploitation support
+ */
+JNIEXPORT void JNICALL
+Java_java_util_stream_IntPipeline_promoteGPUCompile(JNIEnv *env, jobject 
obj);
+
 /* Generics reflection support.
  *
  * Returns information about the given class's EnclosingMethod
diff -r fd237da7a113 src/hotspot/share/prims/jvm.cpp
--- a/src/hotspot/share/prims/jvm.cpp   Mon Jan 22 23:06:29 2018 -0800
+++ b/src/hotspot/share/prims/jvm.cpp   Tue Jan 30 10:07:18 2018 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights 
reserved.
+ * Copyright (c) 1997, 2018, 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
@@ -3661,3 +3661,11 @@
 JVM_ENTRY_NO_ENV(jint, JVM_FindSignal(const char *name))
   return os::get_signal_number(name);
 JVM_END
+
+
+// GPU exploitation support stub 
/////////////////////////////////////////////////////////////////////
+
+JVM_ENTRY(void, 
Java_java_util_stream_IntPipeline_promoteGPUCompile(JNIEnv *env, jobject 
thisObj))
+  JVMWrapper("Java_java_util_stream_IntPipeline_promoteGPUCompile");
+  return;
+JVM_END
diff -r fd237da7a113 
src/java.base/share/classes/java/util/stream/AbstractPipeline.java
--- a/src/java.base/share/classes/java/util/stream/AbstractPipeline.java 
Mon Jan 22 23:06:29 2018 -0800
+++ b/src/java.base/share/classes/java/util/stream/AbstractPipeline.java 
Tue Jan 30 10:07:18 2018 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2016, Oracle and/or its affiliates. All rights 
reserved.
+ * Copyright (c) 2012, 2018, 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
@@ -373,6 +373,14 @@
         return sourceStage.parallel;
     }
 
+    /**
+     * Returns the sourceSpliterator
+     *
+     * @return the sourceSpliterator
+     */
+    final Spliterator<?> getSourceSpliterator() {
+       return sourceSpliterator;
+    }
 
     /**
      * Returns the composition of stream flags of the stream source and 
all
diff -r fd237da7a113 
src/java.base/share/classes/java/util/stream/IntPipeline.java
--- a/src/java.base/share/classes/java/util/stream/IntPipeline.java Mon 
Jan 22 23:06:29 2018 -0800
+++ b/src/java.base/share/classes/java/util/stream/IntPipeline.java Tue 
Jan 30 10:07:18 2018 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2017, Oracle and/or its affiliates. All rights 
reserved.
+ * Copyright (c) 2012, 2018, 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
@@ -433,10 +433,33 @@
     }
 
     // Terminal ops from IntStream
+    private static boolean tryGPU = false;
+    protected static native void promoteGPUCompile();
 
     @Override
     public void forEach(IntConsumer action) {
-        evaluate(ForEachOps.makeInt(action, false));
+       boolean instanceOfRangeIntSpliterator = getSourceSpliterator() 
instanceof Streams.RangeIntSpliterator;
+       if (instanceOfRangeIntSpliterator) {
+               Streams.RangeIntSpliterator intRange = 
(Streams.RangeIntSpliterator)getSourceSpliterator();
+               int last = intRange.upTo;
+               if  (intRange.upTo != Integer.MAX_VALUE && intRange.last 
== 1){
+                       last = intRange.upTo + 1;
+               }
+               // tryGPU will be set at runtime using a suitable JVM 
specific method option
+               if (tryGPU) {
+                       for (int i = intRange.from; i < last; i++){
+                               action.accept(i);
+                       }
+                       if (intRange.upTo == Integer.MAX_VALUE && 
intRange.last == 1){
+                               action.accept(Integer.MAX_VALUE);
+                       }
+                       return;
+               }
+       } 
+       evaluate(ForEachOps.makeInt(action, false));
+       if (instanceOfRangeIntSpliterator){
+               promoteGPUCompile();
+       }
     }
 
     @Override
diff -r fd237da7a113 
src/java.base/share/classes/java/util/stream/Streams.java
--- a/src/java.base/share/classes/java/util/stream/Streams.java Mon Jan 22 
23:06:29 2018 -0800
+++ b/src/java.base/share/classes/java/util/stream/Streams.java Tue Jan 30 
10:07:18 2018 +0000
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights 
reserved.
+ * Copyright (c) 2012, 2018, 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
@@ -55,12 +55,12 @@
         // Can never be greater that upTo, this avoids overflow if upper 
bound
         // is Integer.MAX_VALUE
         // All elements are traversed if from == upTo & last == 0
-        private int from;
-        private final int upTo;
+        int from;
+        final int upTo;
         // 1 if the range is closed and the last element has not been 
traversed
         // Otherwise, 0 if the range is open, or is a closed range and 
all
         // elements have been traversed
-        private int last;
+        int last;
 
         RangeIntSpliterator(int from, int upTo, boolean closed) {
             this(from, upTo, closed ? 1 : 0);

--------------------------------------------------------------------------------------------------------------


Regards,
Ben Walsh


Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 
741598. 
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU



More information about the valhalla-dev mailing list