search for: mcfragments

Moving to LLVM dev to discuss the possibility of extending the cast infrastructure to handle this. On Tue, Nov 20, 2012 at 5:51 PM, John McCall <rjmccall at apple.com> wrote: > On Nov 18, 2012, at 5:05 PM, David Blaikie <dblaikie at gmail.com> wrote: >> TypeLoc casting looks bogus. >> >> TypeLoc derived types return true from classof when the dynamic type >>

On Thu, Nov 29, 2012 at 3:49 PM, David Blaikie <dblaikie at gmail.com> wrote: > Moving to LLVM dev to discuss the possibility of extending the cast > infrastructure to handle this. > > On Tue, Nov 20, 2012 at 5:51 PM, John McCall <rjmccall at apple.com> wrote: >> On Nov 18, 2012, at 5:05 PM, David Blaikie <dblaikie at gmail.com> wrote: >>> TypeLoc

On May 5, 2010, at 1:22 PM, Nathan Jeffords wrote: > On Wed, May 5, 2010 at 11:15 AM, Chris Lattner <clattner at apple.com> wrote: > On May 4, 2010, at 11:03 AM, Nathan Jeffords wrote: > ... We basically want one MCStreamer callback to correspond to one statement in the .s file. This makes it easier to handle from the compiler standpoint, but is also very important for the llvm-mc

Hi all, These days I am working on a feature designed to insert nops for IA code generation that will provide performance improvements and performance stability. This feature will not affect other architectures. It will, however, set up an infrastructure for other architectures to do the same, if ever needed. Here are some examples for cases in which nops can improve performance: 1. DSB

On Mon, Feb 29, 2016 at 03:47:49PM -0800, David Blaikie wrote: > On Mon, Feb 29, 2016 at 3:36 PM, Peter Collingbourne <peter at pcc.me.uk> > wrote: > > > Hi David, > > > > The way I imagined that we might want to extend the MCStreamer API (this > > was motivated by DIEData) is by allowing clients to move bytes and fixups > > into the MC layer. >

...ed array, then these are emitted into MCDataFragments where again more heap allocated data, the float appears to be stored in SmallVectorImpl<char>. On top of this I see a lot of MCFillFragments added because of long double padding. All up the code I'm compiling ends up with 276 million MCFragments, which just take a super long time in each phase of compiling (loading from bitcode, emitting, layout and writing). With a peak working set of 30 gigabytes each float is taking around 108 bytes! Is there a more efficient way to do this? Or is there any plan in the works to handle global data more...

On Wed, May 5, 2010 at 11:15 AM, Chris Lattner <clattner at apple.com> wrote: > On May 4, 2010, at 11:03 AM, Nathan Jeffords wrote: > ... We basically want one MCStreamer callback to correspond to one > statement in the .s file. This makes it easier to handle from the compiler > standpoint, but is also very important for the llvm-mc assembly parser > itself. > > This

On Mon, Feb 29, 2016 at 3:36 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: > Hi David, > > The way I imagined that we might want to extend the MCStreamer API (this > was motivated by DIEData) is by allowing clients to move bytes and fixups > into the MC layer. > > This is the sort of API that I was imagining: > > void

> > > The logic to handle this has to go somewhere, putting it in the MCStreamer > *implementation* that needs it is the most logical place. We also aim to > implement an assembler, it doesn't make sense to duplicate this logic in the > compiler and the assembler parser. > > Assembly language has often been *the* intermediate form for between compilers and object

On May 4, 2010, at 11:03 AM, Nathan Jeffords wrote: > This is a brain-dump of my thoughts on the MCStreamer interface after several > days of digging around trying to get a COFF writer working. Great! Something that is worth pointing out is that the MCStreamer API is intended to directly reflect what is happening in .s files. We basically want one MCStreamer callback to correspond to one

...or the same reasons, the nops insertion process also cannot occur until after the encoding phase. Regarding splitting blocks of code, that is essentially what I’m proposing, but at MC level (since this is the level I’m operating in). When needed, a MCPerfNopFragment will be a separator between two MCFragments that contain code (e.g. MCDataFragments). However, a MCPerfNopFragment is not a MCAlignFragment and a block that follows a MCDataFragments will not (necessarily) be aligned as it could be wasteful in terms of code size. Consider the example I provided. Aligning the fragment after the nops to 16B wi...

Attached is a working patch set for llvm to be able to emit arm64 (currently as triple aarch64-apple-ios) mach-o object files, in case someone is interested. I'm not sure if the llvm maintainers want the patch given the previous message that there's going to be an official patch set from apple to support this, but here is mine. What works (tested on an iPhone 5S): * objc strings,

Hi Hal, A pre-emit pass will indeed be preferable. I originally thought of it, too, however I could not figure out how can such a pass have an access to information on instruction sizes and block alignments. I know that for X86, at least, the branch relaxation is happening during the layout phase in the Assembler, where I plan to integrate the nop insertion such that the new MCPerfNopFragment

Hi Michael, Overall patch looks good. I do have a few comments below. My main comment is please try to make the style match that used in the MCMachOStreamer more closely. I intend to refactor more functionality into the base MCObjectStreamer class, and having them use consistent idioms makes this easier; specific instances are included in the comments: -- > diff --git

On Sun, Jul 11, 2010 at 6:10 PM, Chris Lattner <clattner at apple.com> wrote: > This probably needs to be slightly tweaked to work with mainline.  I don't see anything objectionable, but I think Daniel needs to review this one. Updated patch to work with mainline. http://github.com/Bigcheese/llvm-mirror/commit/d19a4c82c18afc4830c09b70f02d162292231c94 - Michael Spencer

This is a brain-dump of my thoughts on the MCStreamer interface after several days of digging around trying to get a COFF writer working. All fragments should be associated with a symbol. For assembler components, a unnammed "virtual" symbol can be used when there is no explicit label defined. Section assignment should be the responsiblity of the object imlementing the MCStreamer

...emitted into > MCDataFragments where again more heap allocated data, the float appears to > be stored in SmallVectorImpl<char>. On top of this I see a lot of > MCFillFragments added because of long double padding. > > All up the code I'm compiling ends up with 276 million MCFragments, which > just take a super long time in each phase of compiling (loading from > bitcode, emitting, layout and writing). With a peak working set of 30 > gigabytes each float is taking around 108 bytes! > > Is there a more efficient way to do this? Or is there any plan in the > wor...

Right now MC is optimized for emitting assembly, but as Rafael pointed out to me over IRC the optimized path should be emitting object files. This WIP patch moves MCSymbolData into MCSymbol.h and makes it a field inside MCSymbol. This eliminates a pointer from MCSymbolData back to MCSymbol, the DenseMap<const MCSymbol *, MCSymbolData *> in MCAssembler, and converts the iplist in