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8212726: Replace some use of drop- and foldArguments with filtering argument combinator in StringConcatFactory

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Reviewed-by: jlaskey, vlivanov
This commit is contained in:
Claes Redestad 2018-10-23 11:03:51 +02:00
parent a633b90085
commit 06a2bb5274
3 changed files with 121 additions and 82 deletions
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58
src/java.base/share/classes/java/lang/invoke/StringConcatFactory.java
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@ -1,5 +1,5 @@
/*
* Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2015, 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
@ -1533,21 +1533,20 @@ public final class StringConcatFactory {
// *ending* index.
for (RecipeElement el : recipe.getElements()) {
// Do the prepend, and put "new" index at index 1
mh = MethodHandles.dropArguments(mh, 2, int.class);
switch (el.getTag()) {
case TAG_CONST: {
MethodHandle prepender = MethodHandles.insertArguments(prepender(String.class), 3, el.getValue());
mh = MethodHandles.foldArguments(mh, 1, prepender,
2, 0, 3 // index, storage, coder
mh = MethodHandles.filterArgumentsWithCombiner(mh, 1, prepender,
1, 0, 2 // index, storage, coder
);
break;
}
case TAG_ARG: {
int pos = el.getArgPos();
MethodHandle prepender = prepender(ptypes[pos]);
mh = MethodHandles.foldArguments(mh, 1, prepender,
2, 0, 3, // index, storage, coder
4 + pos // selected argument
mh = MethodHandles.filterArgumentsWithCombiner(mh, 1, prepender,
1, 0, 2, // index, storage, coder
3 + pos // selected argument
);
break;
}
@ -1557,7 +1556,7 @@ public final class StringConcatFactory {
}
// Fold in byte[] instantiation at argument 0
mh = MethodHandles.foldArguments(mh, 0, NEW_ARRAY,
mh = MethodHandles.foldArgumentsWithCombiner(mh, 0, NEW_ARRAY,
1, 2 // index, coder
);
@ -1572,7 +1571,7 @@ public final class StringConcatFactory {
// and deduce the coder from there. Arguments would be either converted to Strings
// during the initial filtering, or handled by primitive specializations in CODER_MIXERS.
//
// The method handle shape after all length and coder mixers is:
// The method handle shape before and after all length and coder mixers is:
// (int, byte, <args>)String = ("index", "coder", <args>)
byte initialCoder = INITIAL_CODER;
int initialLen = 0; // initial length, in characters
@ -1589,44 +1588,27 @@ public final class StringConcatFactory {
Class<?> argClass = ptypes[ac];
MethodHandle lm = lengthMixer(argClass);
// Read these bottom up:
if (argClass.isPrimitive() && argClass != char.class) {
// 3. Drop old index, producing ("new-index", "coder", <args>)
mh = MethodHandles.dropArguments(mh, 1, int.class);
// 2. Compute "new-index", producing ("new-index", "old-index", "coder", <args>)
// Length mixer needs old index, plus the appropriate argument
mh = MethodHandles.foldArguments(mh, 0, lm,
1, // old-index
3 + ac // selected argument
// Compute new "index" in-place using old value plus the appropriate argument.
mh = MethodHandles.filterArgumentsWithCombiner(mh, 0, lm,
0, // old-index
2 + ac // selected argument
);
// 1. The mh shape here is ("old-index", "coder", <args>); we don't need to recalculate
// the coder for non-char primitive arguments
} else {
MethodHandle cm = coderMixer(argClass);
// 4. Drop old index and coder, producing ("new-index", "new-coder", <args>)
mh = MethodHandles.dropArguments(mh, 2, int.class, byte.class);
// 3. Compute "new-index", producing ("new-index", "new-coder", "old-index", "old-coder", <args>)
// Length mixer needs old index, plus the appropriate argument
mh = MethodHandles.foldArguments(mh, 0, lm,
2, // old-index
4 + ac // selected argument
// Compute new "index" in-place using old value plus the appropriate argument.
mh = MethodHandles.filterArgumentsWithCombiner(mh, 0, lm,
0, // old-index
2 + ac // selected argument
);
// 2. Compute "new-coder", producing ("new-coder", "old-index", "old-coder", <args>)
// Coder mixer needs old coder, plus the appropriate argument.
mh = MethodHandles.foldArguments(mh, 0, cm,
2, // old-coder
3 + ac // selected argument
// Compute new "coder" in-place using old value plus the appropriate argument.
mh = MethodHandles.filterArgumentsWithCombiner(mh, 1, cm,
1, // old-coder
2 + ac // selected argument
);
// 1. The mh shape here is ("old-index", "old-coder", <args>)
}
break;