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8212597: Optimize String concatenation setup when using primitive operands

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Reviewed-by: shade
This commit is contained in:
Claes Redestad 2018-10-17 17:35:26 +02:00
parent da989adeb7
commit b3b41df70f
3 changed files with 45 additions and 72 deletions
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53
src/java.base/share/classes/java/lang/invoke/StringConcatFactory.java
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@ -1588,28 +1588,47 @@ public final class StringConcatFactory {
Class<?> argClass = ptypes[ac];
MethodHandle lm = lengthMixer(argClass);
MethodHandle cm = coderMixer(argClass);
// Read this bottom up:
// Read these bottom up:
// 4. Drop old index and coder, producing ("new-index", "new-coder", <args>)
mh = MethodHandles.dropArguments(mh, 2, int.class, byte.class);
if (argClass.isPrimitive() && argClass != char.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
);
// 3. Drop old index, producing ("new-index", "coder", <args>)
mh = MethodHandles.dropArguments(mh, 1, int.class);
// 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
);
// 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
);
// 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
);
// 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
);
// 1. The mh shape here is ("old-index", "old-coder", <args>)
}
// 1. The mh shape here is ("old-index", "old-coder", <args>)
break;
default:
throw new StringConcatException("Unhandled tag: " + el.getTag());