Re: [webkit-dev] want to port JIT to MIPS - how to get of SSE2 now?
ALTERNATE_JSIMMEDIATE is only supported on 64-bit, and all 64-bit x86's have SSE2 – so the ALTERNATE_JSIMMEDIATE code is assuming that SSE2 is present. If we wanted to make ALTERNATE_JSIMMEDIATE being enabled on 32-bit x86 possible, then we would also need to check isSSE2Present() here. To address the problem at a slightly higher level, ENABLE_JIT_OPTIMIZE_ARITHMETIC is intended to guard JIT generation of double precision floating point math. In the long run we will potentially place double precision operations within the domain of the MacroAssembler interface, but this is unlikely to happen before the JIT is ported to another platform that feature a 64-bit register file based FPU (which will help drive ensuring that we get the interface right). I would suggest that ENABLE_JIT_OPTIMIZE_ARITHMETIC is not something interesting to worry about at this stage. It only affects a couple of functions, and shouldn't have any wider ramifications on design decisions – a sensible approach in porting the JIT is to switch the three optimizations switches off and then not thinking about them until after the ported JIT is up and running. (In fact, that is exactly why these three switches exist – to make it possible to port the JIT without worrying about some of the hairier bits of code generation. These compile switches were added when we ported the JIT to x86-64. Only once the JIT was up and running did we switch them on one by one). cheers, G. On Feb 26, 2009, at 5:39 PM, x yz wrote: yes but if isSSE2Present() returns false the code becomes very simple so I doubt it may be slow. what's the benefit to enable/disable ALTERNATE_JSIMMEDIATE? thanks joe --- On Fri, 2/27/09, Gavin Barraclough wrote: From: Gavin Barraclough Subject: Re: [webkit-dev] want to port JIT to MIPS - how to get of SSE2 now? To: "WebKit Development" Date: Friday, February 27, 2009, 6:03 AM SSE2 code generation is guarded by calls to a function 'isSSE2Present()'. On Feb 26, 2009, at 12:27 PM, x yz wrote: Hi, Old version seems use ENABLE_JIT_OPTIMIZE_ARITHMETIC to enable sse2 and only for X86_64, current version changes conf to: 1. you must ENABLE_JIT_OPTIMIZE_ARITHMETIC or else you use interpreter for arithmatic. 2. if ALTERNATE_JSIMMEDIATE not enabled you must have sse2 engine 3. if ALTERNATE_JSIMMEDIATE enabled, you use mmx arithematic, but ALTERNATE_JSIMMEDIATE is enabled in paltform.h only for X86_64 && MAC. That means on X86 you need sse2??? thanks for your time! joe --- On Sun, 2/22/09, x yz wrote: From: x yz Subject: Re: [webkit-dev] want to port JIT to MIPS To: "WebKit Development" , "Gavin Barraclough" Date: Sunday, February 22, 2009, 4:34 PM Thanks a lot otherwise I have misunderstanding. Yes I'll do wrec first. I just want to clean up possible blocking issues. I see wrec uses regparm(3) and jit always use fastcall for X86? In JIT.cpp ctiTrampoline put CallFrame in edi, but how about other arguments - where are they be fetched/poped from stack? when deal with caller/callee saved regs, gcc MIPS just preserves them when necesasary. The problem is after JIT used gcc may not have enough knowledge on "necessary", do we have a way to force gcc always preserve them? how to identify a patch (patchimm/patchptr/patchaddr) relates to a data field in an instruction or relates to an element in a data array? In Mips the former means the 32bit needs to be separated into two 16bits and patched into two instructions. But if a 32bit is a pointer in a pointer array, we can save it directly. rgds joe --- On Fri, 2/20/09, Gavin Barraclough wrote: From: Gavin Barraclough Subject: Re: [webkit-dev] want to port JIT to MIPS To: "WebKit Development" Date: Friday, February 20, 2009, 2:01 PM On Feb 19, 2009, at 8:27 PM, x yz wrote: I'd appreaciate your help to clarify the problem I faced: 1.In JIT.cpp I roughly understand ctiTrampoline() except for sp-0x1C, I guess the 1C includes 6 argument yet the 7th or 1st may be the hidden C++ pointer? And the reserved 1C stack space seems not used? why esi is forced to be 512 rather than use input argument? The JIT allocates a fixed frame on the stack which is used to pass arguments into stub functions. The 0x1C contains a spare word or two to maintain stack alignment. %esi is used in the timeout check mechanism. 2.How to understand the stack balance in ctiVMThrowTrampoline()? why after calling we still add 1C w/o sub 1C before calling? where comes _ZN3JSC11Interpreter12cti_vm_throwEPPv and how do I know which name for Mips? does this one relates to variable argument function call? ctiVMThrowTrampoline is never called as a function (it is declared as a function only to provide a symbol that can be manipulated from C code). ctiVMThrowTrampoline is used
Re: [webkit-dev] want to port JIT to MIPS - how to get of SSE2 now?
yes but if isSSE2Present() returns false the code becomes very simple so I doubt it may be slow. what's the benefit to enable/disable ALTERNATE_JSIMMEDIATE? thanks joe --- On Fri, 2/27/09, Gavin Barraclough wrote: > From: Gavin Barraclough > Subject: Re: [webkit-dev] want to port JIT to MIPS - how to get of SSE2 now? > To: "WebKit Development" > Date: Friday, February 27, 2009, 6:03 AM > SSE2 code generation is guarded by calls to a function > 'isSSE2Present()'. > > On Feb 26, 2009, at 12:27 PM, x yz wrote: > > > > > Hi, > > Old version seems use ENABLE_JIT_OPTIMIZE_ARITHMETIC > to enable sse2 > > and only for X86_64, current version changes conf to: > > 1. you must ENABLE_JIT_OPTIMIZE_ARITHMETIC or else you > use > > interpreter for arithmatic. > > 2. if ALTERNATE_JSIMMEDIATE not enabled you must have > sse2 engine > > 3. if ALTERNATE_JSIMMEDIATE enabled, you use mmx > arithematic, but > > ALTERNATE_JSIMMEDIATE is enabled in paltform.h only > for X86_64 && > > MAC. That means on X86 you need sse2??? > > thanks for your time! > > joe > > > > > > > > --- On Sun, 2/22/09, x yz > wrote: > > > >> From: x yz > >> Subject: Re: [webkit-dev] want to port JIT to MIPS > >> To: "WebKit Development" > , "Gavin > >> Barraclough" > >> Date: Sunday, February 22, 2009, 4:34 PM > >> Thanks a lot otherwise I have misunderstanding. > Yes I'll > >> do wrec first. I just want to clean up possible > blocking > >> issues. > >> > >> I see wrec uses regparm(3) and jit always use > fastcall for > >> X86? > >> In JIT.cpp ctiTrampoline put CallFrame in edi, but > how > >> about other arguments - where are they be > fetched/poped from > >> stack? > >> > >> when deal with caller/callee saved regs, gcc MIPS > just > >> preserves them when necesasary. The problem is > after JIT > >> used gcc may not have enough knowledge on > >> "necessary", do we have a way to force > gcc always > >> preserve > >> them? > >> > >> how to identify a patch > (patchimm/patchptr/patchaddr) > >> relates to a data field in an instruction or > relates to an > >> element in a data array? In Mips the former means > the 32bit > >> needs to be separated into two 16bits and patched > into two > >> instructions. But if a 32bit is a pointer in a > pointer > >> array, we can save it directly. > >> > >> rgds > >> joe > >> > >> > >> --- On Fri, 2/20/09, Gavin Barraclough > >> wrote: > >> > >>> From: Gavin Barraclough > > >>> Subject: Re: [webkit-dev] want to port JIT to > MIPS > >>> To: "WebKit Development" > >> > >>> Date: Friday, February 20, 2009, 2:01 PM > >>> On Feb 19, 2009, at 8:27 PM, x yz wrote: > >>> > >>>> I'd appreaciate your help to clarify > the > >> problem I > >>> faced: > >>>> > >>>> 1.In JIT.cpp I roughly understand > ctiTrampoline() > >>> except for sp-0x1C, I guess the 1C includes 6 > argument > >> yet > >>> the 7th or 1st may be the hidden C++ pointer? > And the > >>> reserved 1C stack space seems not used? why > esi is > >> forced to > >>> be 512 rather than use input argument? > >>> > >>> The JIT allocates a fixed frame on the stack > which is > >> used > >>> to pass arguments into stub functions. The > 0x1C > >> contains a > >>> spare word or two to maintain stack alignment. > %esi > >> is used > >>> in the timeout check mechanism. > >>> > >>>> 2.How to understand the stack balance in > >>> ctiVMThrowTrampoline()? why after calling we > still add > >> 1C > >>> w/o sub 1C before calling? where comes > >>> _ZN3JSC11Interpreter12cti_vm_throwEPPv and how > do I > >> know > >>> which name for Mips? does this one relates to > variable > >>> argument function call? > >>> > >>> ctiVMThrowTrampoline is never called as a > function (it > >> is > >>> declared as a function only to provide a > symbol that > >> can be > >>> manipulated from C code). > ctiVMThrowTrampoline is > >> used in > >>> returning back from
Re: [webkit-dev] want to port JIT to MIPS - how to get of SSE2 now?
SSE2 code generation is guarded by calls to a function 'isSSE2Present()'. On Feb 26, 2009, at 12:27 PM, x yz wrote: Hi, Old version seems use ENABLE_JIT_OPTIMIZE_ARITHMETIC to enable sse2 and only for X86_64, current version changes conf to: 1. you must ENABLE_JIT_OPTIMIZE_ARITHMETIC or else you use interpreter for arithmatic. 2. if ALTERNATE_JSIMMEDIATE not enabled you must have sse2 engine 3. if ALTERNATE_JSIMMEDIATE enabled, you use mmx arithematic, but ALTERNATE_JSIMMEDIATE is enabled in paltform.h only for X86_64 && MAC. That means on X86 you need sse2??? thanks for your time! joe --- On Sun, 2/22/09, x yz wrote: From: x yz Subject: Re: [webkit-dev] want to port JIT to MIPS To: "WebKit Development" , "Gavin Barraclough" Date: Sunday, February 22, 2009, 4:34 PM Thanks a lot otherwise I have misunderstanding. Yes I'll do wrec first. I just want to clean up possible blocking issues. I see wrec uses regparm(3) and jit always use fastcall for X86? In JIT.cpp ctiTrampoline put CallFrame in edi, but how about other arguments - where are they be fetched/poped from stack? when deal with caller/callee saved regs, gcc MIPS just preserves them when necesasary. The problem is after JIT used gcc may not have enough knowledge on "necessary", do we have a way to force gcc always preserve them? how to identify a patch (patchimm/patchptr/patchaddr) relates to a data field in an instruction or relates to an element in a data array? In Mips the former means the 32bit needs to be separated into two 16bits and patched into two instructions. But if a 32bit is a pointer in a pointer array, we can save it directly. rgds joe --- On Fri, 2/20/09, Gavin Barraclough wrote: From: Gavin Barraclough Subject: Re: [webkit-dev] want to port JIT to MIPS To: "WebKit Development" Date: Friday, February 20, 2009, 2:01 PM On Feb 19, 2009, at 8:27 PM, x yz wrote: I'd appreaciate your help to clarify the problem I faced: 1.In JIT.cpp I roughly understand ctiTrampoline() except for sp-0x1C, I guess the 1C includes 6 argument yet the 7th or 1st may be the hidden C++ pointer? And the reserved 1C stack space seems not used? why esi is forced to be 512 rather than use input argument? The JIT allocates a fixed frame on the stack which is used to pass arguments into stub functions. The 0x1C contains a spare word or two to maintain stack alignment. %esi is used in the timeout check mechanism. 2.How to understand the stack balance in ctiVMThrowTrampoline()? why after calling we still add 1C w/o sub 1C before calling? where comes _ZN3JSC11Interpreter12cti_vm_throwEPPv and how do I know which name for Mips? does this one relates to variable argument function call? ctiVMThrowTrampoline is never called as a function (it is declared as a function only to provide a symbol that can be manipulated from C code). ctiVMThrowTrampoline is used in returning back from JIT generated code, in the case of an exception. 3.I know how to handle jump in Mips, but not sure how/when to handle patchAddress/patchImm/patchPointer because I'm not sure the instructions related. I guess all patches are for last 32bit IMM field of instructions. Mips can't load 32bit in one instruction, thus I need to know the instruction before I can patch/add in the 32bit data. 4.I'm kind of want no asm code outside folder, any plan for that? No. The assembler is intended to be independent of JavaScript types - it's just an assembler. The asm trampolines are specific to the JIT. It is currently the intention that architecture specific parts of the JIT implementation will remain in the jit folder. I'd suggest that in attempting to port the jit, WREC would be a good place to start. cheers, G. rgds joe --- On Mon, 2/16/09, x yz wrote: From: x yz Subject: Re: [webkit-dev] want to port JIT to MIPS - when WREC/JIT enabled? To: "Gavin Barraclough" Cc: "WebKit Development" Date: Monday, February 16, 2009, 5:25 AM Hi, from paltform.h it is enabled only on X86 MAC/WIN; from javaScriptCore.pri it is also enabled for (QT_ARCH,i386). But, from config.log I see them are enabled! how can I run WREC/JIT test so I can trace in X86 asm coce generated? thanks a lot. joe --- On Sat, 2/7/09, Gavin Barraclough wrote: From: Gavin Barraclough Subject: Re: [webkit-dev] want to port JIT to MIPS - using X86::ecx as base To: last...@yahoo.com Cc: "WebKit Development" Date: Saturday, February 7, 2009, 7:08 AM On Feb 6, 2009, at 2:52 PM, x yz wrote: 1.what's the meaning of ALTERNATE_JSIMMEDIATE and slow case? On x86-64 we use a different implementation of the class JSImmediate. See JSImmediate.h. Re 'slow case', in the JIT code generation is performed as two passes over the bytecode – see JIT::privateCompileMainPass and JIT::privateCompileSlowCases. 2.how come the following code can use ECX as base register? load32(Address(X86::ecx, FIELD_OFFSET(Structure,
Re: [webkit-dev] want to port JIT to MIPS - how to get of SSE2 now?
Hi, Old version seems use ENABLE_JIT_OPTIMIZE_ARITHMETIC to enable sse2 and only for X86_64, current version changes conf to: 1. you must ENABLE_JIT_OPTIMIZE_ARITHMETIC or else you use interpreter for arithmatic. 2. if ALTERNATE_JSIMMEDIATE not enabled you must have sse2 engine 3. if ALTERNATE_JSIMMEDIATE enabled, you use mmx arithematic, but ALTERNATE_JSIMMEDIATE is enabled in paltform.h only for X86_64 && MAC. That means on X86 you need sse2??? thanks for your time! joe --- On Sun, 2/22/09, x yz wrote: > From: x yz > Subject: Re: [webkit-dev] want to port JIT to MIPS > To: "WebKit Development" , "Gavin Barraclough" > > Date: Sunday, February 22, 2009, 4:34 PM > Thanks a lot otherwise I have misunderstanding. Yes I'll > do wrec first. I just want to clean up possible blocking > issues. > > I see wrec uses regparm(3) and jit always use fastcall for > X86? > In JIT.cpp ctiTrampoline put CallFrame in edi, but how > about other arguments - where are they be fetched/poped from > stack? > > when deal with caller/callee saved regs, gcc MIPS just > preserves them when necesasary. The problem is after JIT > used gcc may not have enough knowledge on > "necessary", do we have a way to force gcc always > preserve > them? > > how to identify a patch (patchimm/patchptr/patchaddr) > relates to a data field in an instruction or relates to an > element in a data array? In Mips the former means the 32bit > needs to be separated into two 16bits and patched into two > instructions. But if a 32bit is a pointer in a pointer > array, we can save it directly. > > rgds > joe > > > --- On Fri, 2/20/09, Gavin Barraclough > wrote: > > > From: Gavin Barraclough > > Subject: Re: [webkit-dev] want to port JIT to MIPS > > To: "WebKit Development" > > > Date: Friday, February 20, 2009, 2:01 PM > > On Feb 19, 2009, at 8:27 PM, x yz wrote: > > > > > I'd appreaciate your help to clarify the > problem I > > faced: > > > > > > 1.In JIT.cpp I roughly understand ctiTrampoline() > > except for sp-0x1C, I guess the 1C includes 6 argument > yet > > the 7th or 1st may be the hidden C++ pointer? And the > > reserved 1C stack space seems not used? why esi is > forced to > > be 512 rather than use input argument? > > > > The JIT allocates a fixed frame on the stack which is > used > > to pass arguments into stub functions. The 0x1C > contains a > > spare word or two to maintain stack alignment. %esi > is used > > in the timeout check mechanism. > > > > > 2.How to understand the stack balance in > > ctiVMThrowTrampoline()? why after calling we still add > 1C > > w/o sub 1C before calling? where comes > > _ZN3JSC11Interpreter12cti_vm_throwEPPv and how do I > know > > which name for Mips? does this one relates to variable > > argument function call? > > > > ctiVMThrowTrampoline is never called as a function (it > is > > declared as a function only to provide a symbol that > can be > > manipulated from C code). ctiVMThrowTrampoline is > used in > > returning back from JIT generated code, in the case of > an > > exception. > > > > > 3.I know how to handle jump in Mips, but not sure > > how/when to handle patchAddress/patchImm/patchPointer > > because I'm not sure the instructions related. I > guess > > all patches are for last 32bit IMM field of > instructions. > > > Mips can't load 32bit in one instruction, > thus I > > need to know the instruction before I can patch/add in > the > > 32bit data. > > > > > > 4.I'm kind of want no asm code outside > > folder, any plan for that? > > > > No. The assembler is intended to be independent of > > JavaScript types - it's just an assembler. The > asm > > trampolines are specific to the JIT. It is currently > the > > intention that architecture specific parts of the JIT > > implementation will remain in the jit folder. > > > > I'd suggest that in attempting to port the jit, > WREC > > would be a good place to start. > > > > cheers, > > G. > > > > > > > > rgds > > > joe > > > > > > --- On Mon, 2/16/09, x yz > > > wrote: > > > > > >> From: x yz > > >> Subject: Re: [webkit-dev] want to port JIT to > MIPS > > - when WREC/JIT enabled? > > >> To: "Gavin Barraclough" > > > > >> Cc: "WebKit Development" > > > > >> Date: Monday, February 16, 2009, 5:25 AM > > >> Hi, > > >> from paltform.h it is enabled only on X86 > MAC/WIN; > > from > > >> javaScriptCore.pri it is also enabled for > > (QT_ARCH,i386). > > >> But, from config.log I see them are enabled! > > >> > > >> how can I run WREC/JIT test so I can trace in > X86 > > asm coce > > >> generated? > > >> thanks a lot. > > >> joe > > >> > > >> > > >> > > >> --- On Sat, 2/7/09, Gavin Barraclough > > >> wrote: > > >> > > >>> From: Gavin Barraclough > > > > >>> Subject: Re: [webkit-dev] want to port > JIT to > > MIPS - > > >> using X86::ecx as base > > >>> To: last...@yahoo.com > > >>> Cc: "WebKit Development" > > >> > > >>> Date: Saturday, February 7, 2009, 7:08 AM > > >>> On Feb 6, 2009, at 2:52 PM, x yz wrote: > > >>>
