similar to: [LLVMdev] Contants generation

Hi Elena, > I’d like to generate constants inside .text in order to use ip-relative > loads, when the code model is “large”. I don't think this is a sequence the x86 backend supports at the moment, but it is how ARM handles its constant-pools. The outline is that you have a pass which looks through a functions constpool uses and emits a pseudo-instruction for each, which is then

Hi again, Actually, I've just been looking at the existing code and the ARM solution may be over-complicated for this situation. You should be able to override EmitConstantPool directly, or possibly even just override getSectionForConstantKind in X86LinuxTargetObjectFile (and perhaps others) to return .text. Tim.

I am working towards a more complete solution for large constants in mips 16 (ala Arm constant islands and such). That is part of why I'm busy expanding all macros being emitted in the mips 16 compiler (almost done). I'm wondering if there is a poor mans approach for large constants that can be done very simply that I can add just for now. Gcc mips 16 places them after the function

Hi Reed, > I'm wondering if there is already some mechanism where I can assign literals > to the text section and get a label for where it has been stored. I think putting them in the text section is reasonably simple, though doesn't have a generic "pleasePutConstantsAfterFunctions()" call in LLVM. A good place to start would be the reverse of my recent patch to AArch64

That what I actually did now, locally in the code. But I still see the " movabsq" .text .align 8, 0x90 .LCPI0_0: .quad 4606281698874543309 # double 0.9 .LCPI0_1: .quad 4631147119616759172 # double 42.2794408 .LCPI0_2: .long 1065353216 # float 1 .zero 4 ... movabsq $.LCPI0_1, %rax # encoding: [0x48,0xb8,A,A,A,A,A,A,A,A]

Hi all, I analyzed more and ready (1) to describe the problem and (2) I have a proposal. (1) Problem description: In X86_64 target the Code Model is "Large". It means that address is 64-bit and IP-relative memory operand can't be used in this case. (Because in IP-relative memory operand the displacement is 32-bit). In order to load constant, we use 2 instructions. movabsq

>> I think that the improved behavior for consts should be acceptable in the large model. But that's just me. > By default, all constants should be in a special read-only section, and this section may be far from the text section. Why should they? The only reason I can think of is to support execute-only pages, but isn't that the less common use-case? From what I could tell from

Hi Elena, > (2) Proposal > Define one more Code Model, let's say "LargeNearConst", which will allow to put constants in .text. Isn't that a little heavy-handed? The large model only requires the less efficient access for symbols we can't control, and in fact x86 still uses pc-relative conditional branches within a function so it can't pretend to support a single

> I think that the improved behavior for consts should be acceptable in the large model. But that's just me. By default, all constants should be in a special read-only section, and this section may be far from the text section. I'm working with JIT model or with only one object file. The code model, when all constants are near, we can call "LargeJIT". (Is it sounds better

Why did you take out the constant island code for Arm 64? Just did not need it? On 02/21/2013 12:01 PM, Tim Northover wrote: > Hi Reed, > >> I'm wondering if there is already some mechanism where I can assign literals >> to the text section and get a label for where it has been stored. > > I think putting them in the text section is reasonably simple, though >

Currently llvm crashes on following code, run through llc: declare void @llvm.experimental.stackmap(i64, i32, ...) define void @foo() { tail call void (i64, i32, ...)* @llvm.experimental.stackmap(i64 0, i32 0, i64 9223372036854775807) ret void } The issue is that 9223372036854775807 (decimal for 0x7fffffffffffffff) is the "empty key" for an int64_t, and in

Hi, I'm building a new backend which can only load very limited range of imm. So I decided to use constant pool, and place constant pool entries close enough to instructions use the entries (we have very limited range PC-relative memory load). However, lld & llc output the object files that gather all constant pool entries into one section. How can I make them mix these entries into code

On 8/20/07, Anton Korobeynikov <asl at math.spbu.ru> wrote: > Hello, Tomas. > > > So far I have only been using LLVM at the user level. And I'm not sure > > how this problem should be solved. It would be really nice if there > > was a way to specify something like: > > ******************************************************************* > >

On Mon, 20 Aug 2007, Tomas Lindquist Olsen wrote: > I'm working on a LLVM based compiler for the D programming language by > Walter Bright. Nifty. > D allows static arrays up to 16MB in size. I'm initializing global > static arrays with a constant initializer. But D requires that (per > default) static arrays are initialized with the default initializer > for the

> > D allows static arrays up to 16MB in size. I'm initializing global > > static arrays with a constant initializer. But D requires that (per > > default) static arrays are initialized with the default initializer > > for the element type. For float this happens to be NaN, so I cannot > > use a 'zeroinitializer'. > > Wow, this *is* bad. I think

Chris Lattner wrote: >> D allows static arrays up to 16MB in size. I'm initializing global >> static arrays with a constant initializer. But D requires that (per >> default) static arrays are initialized with the default initializer >> for the element type. For float this happens to be NaN, so I cannot >> use a 'zeroinitializer'. > > Wow, this *is*

I need to load names, from the table ''domains'' into an array (frequently used in my app..) ALL_DOMAINS = Domain.find(:all).map { |d| d.name }.compact I tried to write it in an initialize or in my application.rb BUT problem : when I run a rake db:migrate initially (after creating the database) I get an error.. rake db:migrate --trace (in

Hello, Tomas. > So far I have only been using LLVM at the user level. And I'm not sure > how this problem should be solved. It would be really nice if there > was a way to specify something like: > ******************************************************************* > @_D9arrayinit5tableG32f = global [32 x float] [ 32 x float 0x7FF8000000000000 ] >

Hi there, I've created a bug on llvm: http://www.llvm.org/bugs/show_bug.cgi?id=9582 Basically, ARM, Thumb and data mapping symbols should have been exported in the ELF file, so the linker can work correctly. I can do the change and create some test cases, but I haven't been paying much attention to recent MC developments. Is ArmAsmPrinter the place to change for that, or is there an MC

Hi all. I'm working on a LLVM based compiler for the D programming language by Walter Bright. D allows static arrays up to 16MB in size. I'm initializing global static arrays with a constant initializer. But D requires that (per default) static arrays are initialized with the default initializer for the element type. For float this happens to be NaN, so I cannot use a