Hi Lu, as you are probably aware, LiftoffRegister needs to be able to store any register that should be used inside of Liftoff. If you want to add another register class, you first need to decide how to encode it as a Liftoff register. For the existing register classes, there is this nice description and illustration in liftoff-register.h <https://source.chromium.org/chromium/chromium/src/+/master:v8/src/wasm/baseline/liftoff-register.h;l=82;drc=3dffdf037bab9e1cfa70d23d4d797517eda149ac> . If you change the encoding, you should make sure that all the existing accessors are still working correctly (is_gp(), is_gp(), gp(), fp(), ...). And you need to implement new accessors for the new register class. Next, you need to actually use your new register class wherever that's needed.
The second failure points to problems with registers used for passing parameters. See the comments in LiftoffRegister::from_external_code for details. Hope that helps. It's easy to mess up unfortunately, and hard to debug. -Clemens On Wed, Jan 13, 2021 at 1:53 PM [email protected] <[email protected]> wrote: > I am a developer on V8-RISCV(https://github.com/v8-riscv/v8). > I am working on porting RVV to V8. > On liftoff compiler, there are four Reg types : > > - kGpReg > - kFpReg > - kGpRegPair > - kFpRegPair > > On ARM64/X64 simd register be aliased Fp. > But on riscv-v , vector register has 32 independent VLEN bit registers. > I want to know how i add a Vector register type？ > > I try to add a new type on liftoff-register.h: > ``` > > 1. enum RegClass : uint8_t { > 2. kGpReg, > 3. kFpReg, > 4. > kGpRegPair = kFpReg + 1 + (kNeedS128RegPair && !kNeedI64RegPair) + > 5. (kNeedVpReg && !kNeedI64RegPair), > 6. > kFpRegPair = kFpReg + 1 + kNeedI64RegPair + (kNeedVpReg && > !kNeedS128RegPair), > 7. kVpReg = kFpReg + 1 + kNeedI64RegPair + kNeedS128RegPair, > 8. kNoReg = kVpReg + kNeedVpReg, > 9. } > > ``` > And set kSimpleFPAliasing false. > > Some test case errors appear, like: > > ``` > Warning: unknown flag --enable-slow-asserts. > Try --help for options > > /home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm/embenchen/box2d.js > :20212: Assertion failed: area > 1.19209290e-07F, at: > Box2D/Collision/Shapes/b2P > olygonShape.cpp,352,ComputeMass at Error > at stackTrace > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm > /embenchen/box2d.js:1053:15) > at ___assert_fail > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit > /asm/embenchen/box2d.js:1520:210) > at __ZNK14b2PolygonShape11ComputeMassEP10b2MassDataf > [b2PolygonShape::Comput > eMass(float*)] > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm/em > benchen/box2d.js:16785:3) > at __ZN6b2Body13ResetMassDataEv [b2Body::ResetMassData()] > (/home/yahan/v8/v8 > .snapshot-20200531/v8-cr/v8/test/mjsunit/asm/embenchen/box2d.js:15268:71) > at __ZN6b2Body13CreateFixtureEPK12b2FixtureDef > [b2Body::CreateFixture(b2Fixt > ureDef?*)] > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm/embenc > hen/box2d.js:17783:2) > at __ZN6b2Body13CreateFixtureEPK7b2Shapef [b2Body::CreateFixture(float*)] > (/ > > home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm/embenchen/box2d.js: > 19192:7) > at _main > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm/embe > nchen/box2d.js:14031:4) > at Object.callMain > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsuni > t/asm/embenchen/box2d.js:20193:30) > at doRun > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm/embe > nchen/box2d.js:20250:25) > at run > (/home/yahan/v8/v8.snapshot-20200531/v8-cr/v8/test/mjsunit/asm/embenc > hen/box2d.js:20265:5) > throw e; > ^ > Command: out/riscv64.no.sim/d8 --test test/mjsunit/mjsunit.js > test/mjsunit/asm/e > mbenchen/box2d.js --random-seed=-1764491966 --nohard-abort > --enable-slow-asserts > --verify-heap --testing-d8-test-runner > ```` > > ``` > yahan@2b971f1ad76e:~/v8-riscv64 $ ./out/riscv64.no.sim/d8 > ./test/mjsunit/mjsunit > .js ./test/mjsunit/regress/wasm/regress-1029642.js > > > # Fatal error in ../../src/wasm/baseline/liftoff-register.h, line 223 > # Debug check failed: 0 == code % 2 (0 vs. 1). > > > > #FailureMessage Object: 0x7f7cc2f9c560 > ==== C stack trace =============================== > > ./out/riscv64.no.sim/d8(v8::base::debug::StackTrace::StackTrace()+0x1e) > [0x5 > 5ab26e1ad0e] > ./out/riscv64.no.sim/d8(+0x48991bd) [0x55ab26e121bd] > ./out/riscv64.no.sim/d8(V8_Fatal(char const*, int, char const*, > ...)+0x231) > [0x55ab26dfcfa1] > ./out/riscv64.no.sim/d8(+0x488396c) [0x55ab26dfc96c] > ./out/riscv64.no.sim/d8(V8_Dcheck(char const*, int, char const*)+0x27) > [0x55 > ab26dfd047] > > ./out/riscv64.no.sim/d8(v8::internal::wasm::LiftoffRegister::from_external_c > ode(v8::internal::wasm::RegClass, v8::internal::wasm::ValueType, > int)+0x90) [0x5 > 5ab2584e150] > ./out/riscv64.no.sim/d8(+0x32e51c2) [0x55ab2585e1c2] > ./out/riscv64.no.sim/d8(+0x32e47a7) [0x55ab2585d7a7] > ./out/riscv64.no.sim/d8(+0x32e214d) [0x55ab2585b14d] > ./out/riscv64.no.sim/d8(+0x32e17ad) [0x55ab2585a7ad] > ./out/riscv64.no.sim/d8(+0x32dd23f) [0x55ab2585623f] > > ./out/riscv64.no.sim/d8(v8::internal::wasm::ExecuteLiftoffCompilation(v8::in > ternal::AccountingAllocator*, v8::internal::wasm::CompilationEnv*, > v8::internal: > :wasm::FunctionBody const&, int, v8::internal::wasm::ForDebugging, > v8::internal: > :Counters*, v8::internal::wasm::WasmFeatures*, v8::internal::Vector, std::_ > _1::unique_ptrinternal::wasm::DebugSideTable> >*, int)+0x49f) > [0x55ab2585534f] > > ./out/riscv64.no.sim/d8(v8::internal::wasm::WasmCompilationUnit::ExecuteFunc > tionCompilation(v8::internal::wasm::WasmEngine*, > v8::internal::wasm::Compilation > Env*, std::__1::shared_ptr const&, v8::int > ernal::Counters*, v8::internal::wasm::WasmFeatures*)+0x46b) > [0x55ab259140db] > > ./out/riscv64.no.sim/d8(v8::internal::wasm::WasmCompilationUnit::ExecuteComp > ilation(v8::internal::wasm::WasmEngine*, > v8::internal::wasm::CompilationEnv*, st > d::__1::shared_ptr const&, v8::internal::C > ounters*, v8::internal::wasm::WasmFeatures*)+0xe8) [0x55ab25913aa8] > ./out/riscv64.no.sim/d8(+0x33e1a8f) [0x55ab2595aa8f] > ./out/riscv64.no.sim/d8(+0x33ea6c2) [0x55ab259636c2] > ./out/riscv64.no.sim/d8(v8::platform::DefaultJobWorker::Run()+0xd5) > [0x55ab2 > 6e1db95] > > ./out/riscv64.no.sim/d8(v8::platform::DefaultWorkerThreadsTaskRunner::Worker > Thread::Run()+0x5f) [0x55ab26e2782f] > ./out/riscv64.no.sim/d8(v8::base::Thread::NotifyStartedAndRun()+0x36) > [0x55a > b26e0f7f6] > ./out/riscv64.no.sim/d8(+0x489602d) [0x55ab26e0f02d] > /lib/x86_64-linux-gnu/libpthread.so.0(+0x9609) [0x7f7cc3d00609] > /lib/x86_64-linux-gnu/libc.so.6(clone+0x43) [0x7f7cc3ab2103] > Received signal 4 ILL_ILLOPN 55ab26e0dcf1 > Illegal instruction (core dumped) > ``` > > > -- > -- > v8-dev mailing list > [email protected] > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/v8-dev/3f8ed1b9-c7a7-4af6-be4a-4753ccf5c35cn%40googlegroups.com > <https://groups.google.com/d/msgid/v8-dev/3f8ed1b9-c7a7-4af6-be4a-4753ccf5c35cn%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- Clemens Backes Software Engineer [email protected] Google Germany GmbH Erika-Mann-Straße 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Diese E-Mail ist vertraulich. Falls sie diese fälschlicherweise erhalten haben sollten, leiten Sie diese bitte nicht an jemand anderes weiter, löschen Sie alle Kopien und Anhänge davon und lassen Sie mich bitte wissen, dass die E-Mail an die falsche Person gesendet wurde. This e-mail is confidential. If you received this communication by mistake, please don't forward it to anyone else, please erase all copies and attachments, and please let me know that it has gone to the wrong person. -- -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-dev/CAGO%3DqhAMy5msm2T4B5BovBTNO4_Dzw1N3hu1dTBKYXg6HUV2CQ%40mail.gmail.com.
