Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v12]
On Fri, 8 Apr 2022 18:32:06 GMT, Sandhya Viswanathan wrote: > My suggestion is to keep the -ve path assembly optimization in this patch. > When the optimization in IR is introduced, the assembly could then be > simplified as suggested by @merykitty. Okay. Lets do that as part of JDK-8282365. - PR: https://git.openjdk.java.net/jdk/pull/7572
Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v12]
On Fri, 8 Apr 2022 01:05:33 GMT, Srinivas Vamsi Parasa wrote: >> Optimizes the divideUnsigned() and remainderUnsigned() methods in >> java.lang.Integer and java.lang.Long classes using x86 intrinsics. This >> change shows 3x improvement for Integer methods and upto 25% improvement for >> Long. This change also implements the DivMod optimization which fuses >> division and modulus operations if needed. The DivMod optimization shows 3x >> improvement for Integer and ~65% improvement for Long. > > Srinivas Vamsi Parasa has updated the pull request incrementally with one > additional commit since the last revision: > > uncomment zero in integer div, mod test My suggestion is to keep the -ve path assembly optimization in this patch. When the optimization in IR is introduced, the assembly could then be simplified as suggested by @merykitty. - PR: https://git.openjdk.java.net/jdk/pull/7572
Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v12]
On Fri, 8 Apr 2022 01:05:33 GMT, Srinivas Vamsi Parasa wrote: >> Optimizes the divideUnsigned() and remainderUnsigned() methods in >> java.lang.Integer and java.lang.Long classes using x86 intrinsics. This >> change shows 3x improvement for Integer methods and upto 25% improvement for >> Long. This change also implements the DivMod optimization which fuses >> division and modulus operations if needed. The DivMod optimization shows 3x >> improvement for Integer and ~65% improvement for Long. > > Srinivas Vamsi Parasa has updated the pull request incrementally with one > additional commit since the last revision: > > uncomment zero in integer div, mod test Agree, this is reasonable suggestion. It could be done in these changes. - PR: https://git.openjdk.java.net/jdk/pull/7572
Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v12]
On Fri, 8 Apr 2022 01:59:10 GMT, Quan Anh Mai wrote: > Personally, I think the optimisation for `div < 0` should be handled by the > mid-end optimiser, which will not only give us the advantages of dead code > elimination, but also global code motion. I would suggest the backend only > doing `xorl rdx, rdx; divl $div$$Register` and the optimisation for `div < 0` > will be implemented as a part of JDK-8282365. What do you think? I agree that we can do more optimizations with constants as JDK-8282365 suggested. But I think we should proceed with current changes as they are after fixing remaining issues. I assume that you are talking about case when `divisor` is constant (or both). Because if it is not, IR optimization will not help - we don't profile arithmetic values so we can't generate uncommon trap path without some profiling information. - PR: https://git.openjdk.java.net/jdk/pull/7572
Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v12]
On Fri, 8 Apr 2022 01:05:33 GMT, Srinivas Vamsi Parasa wrote: >> Optimizes the divideUnsigned() and remainderUnsigned() methods in >> java.lang.Integer and java.lang.Long classes using x86 intrinsics. This >> change shows 3x improvement for Integer methods and upto 25% improvement for >> Long. This change also implements the DivMod optimization which fuses >> division and modulus operations if needed. The DivMod optimization shows 3x >> improvement for Integer and ~65% improvement for Long. > > Srinivas Vamsi Parasa has updated the pull request incrementally with one > additional commit since the last revision: > > uncomment zero in integer div, mod test Personally, I think the optimisation for `div < 0` should be handled by the mid-end optimiser, which will not only give us the advantages of dead code elimination, but also global code motion. I would suggest the backend only doing `xorl rdx, rdx; divl $div$$Register` and the optimisation for `div < 0` will be implemented as a part of JDK-8282365. What do you think? Thanks. - PR: https://git.openjdk.java.net/jdk/pull/7572
Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v12]
On Fri, 8 Apr 2022 01:05:33 GMT, Srinivas Vamsi Parasa wrote: >> Optimizes the divideUnsigned() and remainderUnsigned() methods in >> java.lang.Integer and java.lang.Long classes using x86 intrinsics. This >> change shows 3x improvement for Integer methods and upto 25% improvement for >> Long. This change also implements the DivMod optimization which fuses >> division and modulus operations if needed. The DivMod optimization shows 3x >> improvement for Integer and ~65% improvement for Long. > > Srinivas Vamsi Parasa has updated the pull request incrementally with one > additional commit since the last revision: > > uncomment zero in integer div, mod test Good. I forgot before to ask about how you handle devision by 0 and now you added check for it. Let me run testing before approval. - PR: https://git.openjdk.java.net/jdk/pull/7572
Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v12]
> Optimizes the divideUnsigned() and remainderUnsigned() methods in > java.lang.Integer and java.lang.Long classes using x86 intrinsics. This > change shows 3x improvement for Integer methods and upto 25% improvement for > Long. This change also implements the DivMod optimization which fuses > division and modulus operations if needed. The DivMod optimization shows 3x > improvement for Integer and ~65% improvement for Long. Srinivas Vamsi Parasa has updated the pull request incrementally with one additional commit since the last revision: uncomment zero in integer div, mod test - Changes: - all: https://git.openjdk.java.net/jdk/pull/7572/files - new: https://git.openjdk.java.net/jdk/pull/7572/files/bfb6c02e..3e3fc977 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7572&range=11 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7572&range=10-11 Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod Patch: https://git.openjdk.java.net/jdk/pull/7572.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/7572/head:pull/7572 PR: https://git.openjdk.java.net/jdk/pull/7572
