similar to: [LLVMdev] Accounting for code size

On Sep 28, 2007, at 10:27 AM, Sandro Magi wrote: > In my quest to account for memory, I've now come to the in-memory IR, > and the generated code. I want to book the generated code memory > against the agent that is generating the code. > > I see that LLVM's Function class [1] has a size function; what does > this represent and can I use it to account for the space used

Hi everyone, vmkit requires to know the size of a jitted method before emitting the method. This allows to allocate the correct size for the method. The attached patch creates this functionality when the flag SizedMemoryCode is on. In order to implement this functionality, i had to virtualize some MachineCodeEmitter functions. Is it OK to commit the patch? Thanks, Nicolas --------------

Hi Evan, Evan Cheng wrote: > 1) How are you computing size of the method being > jitted? I add a new pass with addSimpleCodeEmitter, with the emitter being a SizeEmitter. Since the target calls the emitter with functions such as writeByte, writeWord, etc.... the SizeEmitter class implements these function by incrementing a counter. At the end of the pass, the code size of the

Evan Cheng wrote: > On Apr 1, 2008, at 12:50 AM, Nicolas Geoffray wrote: > > > That's a hack. :-) It is if you think that code emitter should only be used for actually writing somewhere the data. It is not if you find it another useful utility ;-) > Some targets already have ways to compute the exact > size of a function. See ARM::GetFunctionSize()

Evan Cheng wrote: > > Let's see. ARM has it already. PPC has getNumBytesForInstruction so > you only need to add one to compute function size. Also you only need > to implement it for targets that support JIT right now, which leaves > Alpha and X86. I'm guessing Alpha is using fixed encoding so it should > be pretty easy. Or you can just punt it and let the target

Hi, Two questions. 1) How are you computing size of the method being jitted? 2) Why not simply add the functionality of allocating emission buffer of specific size to MachineCodeEmitter instead? Thanks, Evan On Mar 30, 2008, at 12:05 PM, Nicolas Geoffray wrote: > Hi everyone, > > vmkit requires to know the size of a jitted method before emitting > the method. This allows to

On Apr 1, 2008, at 12:50 AM, Nicolas Geoffray wrote: > Hi Evan, > > Evan Cheng wrote: >> 1) How are you computing size of the method being >> jitted? > > I add a new pass with addSimpleCodeEmitter, with the emitter being a > SizeEmitter. Since the target calls the emitter with functions such as > writeByte, writeWord, etc.... the SizeEmitter class implements these

On Apr 4, 2008, at 11:16 PM, Nicolas Geoffray <nicolas.geoffray at lip6.fr> wrote: > Evan Cheng wrote: >> >> Let's see. ARM has it already. PPC has getNumBytesForInstruction so >> you only need to add one to compute function size. Also you only need >> to implement it for targets that support JIT right now, which leaves >> Alpha and X86. I'm

Hi Evan, Evan Cheng wrote: > > I don't think the duplication is going to be top much of a problem. If > it is, I'll bug you about refactoring. :) > > I don't mean to show how lazy I can be, but I also need to know the size of the exception table emitted in memory (JITDwarfEmitter.cpp). Reviewing it a little, I can not see how things won't be duplicated.

On Apr 4, 2008, at 5:50 AM, Nicolas Geoffray wrote: > Evan Cheng wrote: >> On Apr 1, 2008, at 12:50 AM, Nicolas Geoffray wrote: >> >> >> That's a hack. :-) > > It is if you think that code emitter should only be used for actually > writing somewhere the data. It is not if you find it another useful > utility ;-) Except it's pretty slow at it. :-)

Hi everyone, Here's a patch that enables exception handling when jitting. I've copy/pasted _many_code from lib/Codegen/DwarfWriter.cpp, so we may need to factorize it, but the functionality is there and I'm very happy with it :) lli should now be able to execute the output from llvm-gcc when using exceptions (the UnwindInst instruction is not involved in this patch). Just add the

On Dec 10, 2007, at 9:52 AM, Nicolas Geoffray wrote: > Hi everyone, > > Here's a patch that enables exception handling when jitting. I've > copy/pasted _many_code from lib/Codegen/DwarfWriter.cpp, so we may > need > to factorize it, but the functionality is there and I'm very happy > with > it :) Very nice! I don't know enough about EH, someone else

On Aug 21, 2012, at 2:12 PM, Michael Muller <mmuller at enduden.com> wrote: > > Hi, I found a bug in the code that generates exception tables, I've attached > what I think is the correct fix. > > When you run out of space writing to a buffer, the buffer management code > simply stops writing at the end of the buffer. It is the responsibility of > the caller to

Dear all, Here's a new patch with Evan's comments (thx Evan!) and some cleanups. Now the (duplicated) exception handling code is in a new file: lib/ExecutionEngine/JIT/JITDwarfEmitter. This patch should work on linux/x86 and linux/ppc (tested). Nicolas -------------- next part -------------- An embedded and charset-unspecified text was scrubbed... Name: jit-exceptions.patch URL:

Eric Christopher wrote: > > On Aug 21, 2012, at 2:12 PM, Michael Muller <mmuller at enduden.com> wrote: > > > > > Hi, I found a bug in the code that generates exception tables, I've attached > > what I think is the correct fix. > > > > When you run out of space writing to a buffer, the buffer management code > > simply stops writing at the

On 9/28/07, Chris Lattner <sabre at nondot.org> wrote: > > > MachineCodeEmitter [3] is obtainable from the JIT class, and it > > contains "BufferBegin", "BufferEnd", and "CurBufferPtr" as protected > > members; if they were available, determining the generated code size > > might be possible via some pointer arithmetic. Is there

Hello! Working with LLVM JIT-compiler I found a small bug and I'd like to correct it. Namely, on some tests LLVM fails with message "JIT: Ran out of space for generated machine code!" This error emerges because the test creates big static array. Global variables are placed into memory block for function, that is first seen using given variable. Besides, during memory allocation

Looks sane. Thanks. Evan On Feb 1, 2008, at 1:24 AM, Nicolas Geoffray wrote: > Dear all, > > Here's a new patch with Evan's comments (thx Evan!) and some cleanups. > Now the (duplicated) exception handling code is in a new file: > lib/ExecutionEngine/JIT/JITDwarfEmitter. > > This patch should work on linux/x86 and linux/ppc (tested). > > Nicolas > Index:

Here is the corrected version. Thomas Jablin wrote: > Actually, there is a problem with the patch. Please delay review. > > Thomas Jablin wrote: > >> Hi, >> The following code: >> >> #include<stdio.h> >> >> char bigArray[0x1000000]; >> >> int main(int argc, char **argv) { >> printf("mem: 0x%x\n", (unsigned)

Hi, The following code: #include<stdio.h> char bigArray[0x1000000]; int main(int argc, char **argv) { printf("mem: 0x%x\n", (unsigned) bigArray); return 0; } causes lli to silently fail, even though it compiles correctly with llc. The reason is that in JITEmitter.cpp only checks to see if CurBufferPtr == BufferEnd at the beginning of the function and not after all