Improvements #128
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Improvements #128
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Most implementations of the `Operation.getInputResultHandles()` method return a `LinkedHashSet`, even if the interface demands just `Set`. A few existing implementations returned just `HashSet`, and this commit makes them consistent with the rest.
The code that emits LADD had a typo: the correct descriptor for the `long` type is `J` and not `Z`.
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Note it is probably easiest to review individual commits separately. |
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Previously, all constants were loaded from the constant pool and pushed on the stack using the LDC instruction. This is less efficient than necessary, because for some very commonly used constants, the JVM ISA has dedicated instructions: ICONST_0, ICONST_1 etc. With this commit, all the common constats are loaded using these instructions.
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mkouba
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Oct 17, 2022
| @@ -1177,7 +1177,7 @@ void writeBytecode(MethodVisitor methodVisitor) { | |||
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| @Override | |||
| Set<ResultHandle> getInputResultHandles() { | |||
| return new HashSet<>(Arrays.asList(a1, a2)); | |||
| return new LinkedHashSet<>(Arrays.asList(a1, a2)); | |||
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Hmm, would it make sense to use HashSet everywhere instead? Or clarify the contract of BytecodeCreatorImpl.Operation.getInputResultHandles()?
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I'd like to do some experiments to improve the generated code, and as part of them, I'd probably make this a List, actually.
Previously, the only arithmetic operation available through Gizmo API was addition (IADD etc.). This commit adds multiplication (IMUL etc.), as well as internal helper methods that will help implement more arithmetic operations in the future.
As opposed to comparing `int` values, where the JVM ISA provides instructions that branch directly, comparing `long`, `float` and `double` values is more involved. The LCMP, FCMP* and DCMP* instructions push a comparison result on the stack as an `int` and an `int` branching instruction must be used afterwards.
The `ifReferencesEqual` method emits the IF_ACMPEQ instruction. This commit adds `ifReferencesNotEqual`, which emits IF_ACMPNE. This is useful to generate bytecode similar to what javac generates.
Notably, 4 methods are added to simplify common `returnValue` invocations. The `returnBoolean` and `returnInt` methods simplify returning a constant, `returnNull` simplifies returning the `null` reference, and `returnVoid` makes return from a `void` method or constructor more obvious.
Most notably, `JdkMap.instance(ResultHandle)` is deprecated and replaced by `JdkMap.on(ResultHandle)` to be consistent with other classes.
mkouba
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Oct 17, 2022
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Several improvements:
getInputResultHandles()implementations consistentlongvalues (typo in the type descriptor)returnBoolean,returnInt,returnNullandreturnVoidto simplify common method exitsStringBuilderchainsequals,hashCodeandtoString, similarly to what IDEs doGizmoclass to USAGE.adoc