Re: RFR: 8282221: x86 intrinsics for divideUnsigned and remainderUnsigned methods in java.lang.Integer and java.lang.Long [v4]
On Wed, 6 Apr 2022 06:23:47 GMT, Jatin Bhateja wrote: >>> Also need a jtreg test for this. >> >> Thanks Sandhya for the review. Made the suggested changes and added jtreg >> tests as well. > > Hi @vamsi-parasa , thanks for addressing my comments, looks good to me > otherwise apart from the outstanding comments. @jatin-bhateja Thank you Jatin! - 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 [v4]
On Wed, 6 Apr 2022 00:45:37 GMT, Vladimir Kozlov wrote: >> Thanks for suggesting the enhancement. This enhancement will be implemented >> as a part of https://bugs.openjdk.java.net/browse/JDK-8282365 > > You do need `Ideal()` methods at least to check for dead code. Added the Ideal() methods for checking dead code. Pls see the new commit. - 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 [v4]
On Mon, 4 Apr 2022 07:24:12 GMT, Vamsi Parasa wrote: >> Also need a jtreg test for this. > >> Also need a jtreg test for this. > > Thanks Sandhya for the review. Made the suggested changes and added jtreg > tests as well. Hi @vamsi-parasa , thanks for addressing my comments, looks good to me otherwise apart from the outstanding comments. - 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 [v4]
On Thu, 24 Feb 2022 19:04:37 GMT, Vamsi Parasa wrote: >> src/hotspot/share/opto/divnode.cpp line 881: >> >>> 879: return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : >>> this; >>> 880: } >>> 881: >>> //--Value-- >> >> Ideal transform to replace unsigned divide by cheaper logical right shift >> instruction if divisor is POW will be useful. > > Thanks for suggesting the enhancement. This enhancement will be implemented > as a part of https://bugs.openjdk.java.net/browse/JDK-8282365 You do need `Ideal()` methods at least to check for dead code. - 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 [v4]
On Thu, 24 Feb 2022 14:13:47 GMT, Jatin Bhateja wrote: >> Vamsi Parasa has updated the pull request incrementally with one additional >> commit since the last revision: >> >> fix 32bit build issues > > src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp line 4408: > >> 4406: jmp(done); >> 4407: bind(neg_divisor_fastpath); >> 4408: // Fastpath for divisor < 0: > > How about checking if divisor is +ve or -ve constant and non-constant > dividend in identity routine and setting a flag in IR node, which can be used > to either emit fast / slow path in a new instruction selection pattern. It > will save emitting redundant instructions. Thanks for suggesting the enhancement. This enhancement will be implemented as a part of https://bugs.openjdk.java.net/browse/JDK-8282365 > src/hotspot/share/opto/divnode.cpp line 881: > >> 879: return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : >> this; >> 880: } >> 881: >> //--Value-- > > Ideal transform to replace unsigned divide by cheaper logical right shift > instruction if divisor is POW will be useful. Thanks for suggesting the enhancement. This enhancement will be implemented as a part of https://bugs.openjdk.java.net/browse/JDK-8282365 > src/hotspot/share/opto/divnode.cpp line 897: > >> 895: >> 896: // Either input is BOTTOM ==> the result is the local BOTTOM >> 897: const Type *bot = bottom_type(); > > Can we add constant folding handling when both dividend and divisor are > constants. Thanks for suggesting the enhancement. This enhancement will be implemented as a part of https://bugs.openjdk.java.net/browse/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 [v4]
On Thu, 24 Feb 2022 02:43:46 GMT, 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. > > Vamsi Parasa has updated the pull request incrementally with one additional > commit since the last revision: > > fix 32bit build issues src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp line 4408: > 4406: jmp(done); > 4407: bind(neg_divisor_fastpath); > 4408: // Fastpath for divisor < 0: How about checking if divisor is +ve or -ve constant and non-constant dividend in identity routine and setting a flag in IR node, which can be used to either emit fast / slow path in a new instruction selection pattern. It will save emitting redundant instructions. src/hotspot/share/opto/divnode.cpp line 881: > 879: return (phase->type( in(2) )->higher_equal(TypeLong::ONE)) ? in(1) : > this; > 880: } > 881: > //--Value-- Ideal transform to replace unsigned divide by cheaper logical right shift instruction if divisor is POW will be useful. src/hotspot/share/opto/divnode.cpp line 897: > 895: > 896: // Either input is BOTTOM ==> the result is the local BOTTOM > 897: const Type *bot = bottom_type(); Can we add constant folding handling when both dividend and divisor are constants. - 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 [v4]
> 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. Vamsi Parasa has updated the pull request incrementally with one additional commit since the last revision: fix 32bit build issues - Changes: - all: https://git.openjdk.java.net/jdk/pull/7572/files - new: https://git.openjdk.java.net/jdk/pull/7572/files/13549290..2915b2e7 Webrevs: - full: https://webrevs.openjdk.java.net/?repo=jdk=7572=03 - incr: https://webrevs.openjdk.java.net/?repo=jdk=7572=02-03 Stats: 91 lines in 2 files changed: 49 ins; 42 del; 0 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
