On Tue, 29 Mar 2022 02:24:21 GMT, Jatin Bhateja <jbhat...@openjdk.org> wrote:
>> Implements x86 intrinsics for compare() method in java.lang.Integer and
>> java.lang.Long.
>
> src/hotspot/cpu/x86/x86_64.ad line 12107:
>
>> 12105: instruct compareSignedI_rReg(rRegI dst, rRegI op1, rRegI op2, rRegI
>> tmp, rFlagsReg cr)
>> 12106: %{
>> 12107: match(Set dst (CompareSignedI op1 op2));
>
> Please also include these patterns in x86_32.ad
Will update x86_32.ad as well.
> src/hotspot/cpu/x86/x86_64.ad line 12125:
>
>> 12123: __ movl(tmp, 0);
>> 12124: __ bind(done);
>> 12125: __ movl(dest, tmp);
>
> Please move this in macro-assembly routine.
Sure, will refactor it into a macro-assembly
> src/hotspot/cpu/x86/x86_64.ad line 12178:
>
>> 12176: __ movl(tmp, 0);
>> 12177: __ bind(done);
>> 12178: __ movl(dest, tmp);
>
> Please move this into a macro-assembly routine.
Sure, will do that and update it soon.
> src/hotspot/cpu/x86/x86_64.ad line 12204:
>
>> 12202: __ movl(tmp, 0);
>> 12203: __ bind(done);
>> 12204: __ movl(dest, tmp);
>
> Please move this into macro-assembly routine.
Sure, will do that and update it soon.
> src/hotspot/share/opto/comparenode.hpp line 67:
>
>> 65: CompareUnsignedLNode(Node* in1, Node* in2) : CompareNode(in1, in2) {}
>> 66: virtual int Opcode() const;
>> 67: };
>
> Intent here seems to be to enable further auto-vectorization of newly create
> IR nodes.
Yes, that is the intention.
> test/micro/org/openjdk/bench/java/lang/CompareInteger.java line 78:
>
>> 76: input2[i] = tmp;
>> 77: }
>> 78: }
>
> Logic re-organization suggestion:-
>
>
> for (int i = 0 ; i < BUFFER_SIZE; i++) {
> input1[i] = rng.nextLong();
> }
>
> if (mode.equals("equals") {
> GRADIANT = 0;
> } else if (mode.equals("greaterThanEquals")) {
> GRADIANT = 1;
> } else {
> assert mode.equals("lessThanEqual");
> GRADIANT = -1;
> }
>
> for(int i = 0 ; i < BUFFER_SIZE; i++) {
> input2[i] = input1[i] + i*GRADIANT;
> }
The suggested refactoring is definitely elegant but one rare possibility is
overflow due to the addition/subtraction. The swap logic doesn't have that
problem.
> test/micro/org/openjdk/bench/java/lang/CompareLong.java line 5:
>
>> 3: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
>> 4: *
>> 5: * This code is free software; you can redistribute it and/or modify it
>
> We can unify this benchmark along with integer compare micro.
Sure, will do the unification.
-------------
PR: https://git.openjdk.java.net/jdk/pull/7975
