similar to: [LLVMdev] Is using lots of in-register values in IR bad?

Erkki Lindpere <villane at gmail.com> writes: > I want to experiment with avoiding mutable state as far as I can. At > the moment there are no mutable variables -- only immutable value > types (numerics, bool, vectors, tuples) and I've been doing everything > in LLVM registers. The compiler doesn't generate a single alloca, load > or store at the moment. Ok. Do you

Hi Erkki, > I want to experiment with avoiding mutable state as far as I can. At the moment > there are no mutable variables -- only immutable value types (numerics, bool, > vectors, tuples) and I've been doing everything in LLVM registers. The compiler > doesn't generate a single alloca, load or store at the moment. > > I wonder if it was maybe a bad idea to do it this

Thanks for the reply On Fri, Jul 29, 2011 at 2:06 AM, David A. Greene <greened at obbligato.org>wrote: > Erkki Lindpere <villane at gmail.com> writes: > Ok. Do you ever need to grab the address of something on the stack? If > so you're going to need an alloca. AFAIK, it's the only way to generate > an address for a local object. This is by design of the IR and

hi! I'm using LLVM 3.2. Does it optimize away llvm.pow(llvm.sqrt(x), 2) to `x` with any settings? I tried with llc -O3, but that didn't do it. Would be nice to write |v|² in my language ('v' being a 2D vector say and |...| and ...² being two separate infix "operators") -- when I could compare squares of lengths as well as lengths, and know that the sqrt is optimized

Thanks for the quick reply! I will keep the DIBuilder and Clang's CGDebugInfo as my reference for now. At the moment I want to stick with generating .ll -- it's somewhat easier for me to debug the output of my compiler that way, and I haven't programmed much in C/C++ for years -- mostly been a JVM guy. But at one point I may want to look into bindings or even creating a bootstrapped

Hi, I wanted to add debug info to my language (compiler written in Scala, outputs .ll files), but I found it really hard to do based on the documentation provided at http://llvm.org/docs/SourceLevelDebugging.html (I looked at the specific doc for LLVM 3.0 though) With LLVM 3.0, DI version 8 (which is documented there) seemed to work, except DW_TAG_auto_variable for which I used version tag 11

That's a pretty seriously unsafe floating point optimization. It could be done in fast-math mode, but I doubt we currently do it. --Owen On Apr 23, 2013, at 1:12 PM, Erkki Lindpere <villane at gmail.com> wrote: > hi! > > I'm using LLVM 3.2. Does it optimize away llvm.pow(llvm.sqrt(x), 2) to `x` with any settings? I tried with llc -O3, but that didn't do it. >

On Wed, Mar 20, 2013 at 2:21 PM, Erkki Lindpere <villane at gmail.com> wrote: > Hi, > > I wanted to add debug info to my language (compiler written in Scala, > outputs .ll files), but I found it really hard to do based on the > documentation provided at http://llvm.org/docs/SourceLevelDebugging.html(I looked at the specific doc for LLVM 3.0 though) > > With LLVM 3.0, DI

I've read that LiveValues has been removed from trunk. Did it bitrot or was simply removed because a replacement is available? If it's the former, what caused the bitrotting? If it's the latter, what's the replacement? (I've found LiveVariables but I'm not sure it can be used in a ModulePass). b.r. -- Carlo Alberto Ferraris <cafxx at strayorange.com <mailto:cafxx

LiveVariables is the optimized and tested way to get variable liveness information (it's used by register allocation). Unfortunately it requires a MachineFunction to work - so you'll either need to lower to one of the built-in targets or add your own target to acquire access to this pass. Andrew On 03/31/2011 12:28 PM, Carlo Alberto Ferraris wrote: > I've read that LiveValues

> That's a weird one. Does addr2line work? > $ addr2line -e CGF.so <address> cafxx at ubuntu:~/Projects/llvm2/Debug+Asserts/bin$ objdump -t ../lib/CGF.so | grep flatten 0000000000005622 l F .text 0000000000000aa6 _ZN12_GLOBAL__N_111CGFFunction7flattenEv 00000000000041d6 l F .text 000000000000049c _ZN12_GLOBAL__N_111CGFCallSite7flattenEv

Nella citazione martedì 2 agosto 2011 20:02:08, Michael Ilseman ha scritto: > I'm assuming that you're talking about a situation where this can't be > determined statically in the existing LLVM IR, but you know it's true > and want to put it in (e.g. you're the one generating LLVM IR). Correct. Or, more precisely, I'd like to investigate macro compression, i.e.

I'm trying to figure out how to feed a blockaddress to a switch condition AND destination (basically emulating an indirectbr via a switch; I know it's not a good approach, I'm just experimenting). Suppose I have the following: SwitchInst *s = SwitchInst::Create(...); BasicBlock *bb = ...; PtrToIntInst k = new PtrToIntInst(BlockAddress::get(bb), <TYPE>, "", s);

Consider this IR fragment produced after -O3: > %7: > %8 = phi i8* [ blockaddress(@0, %19), %19 ], [ %12, %11 ] > %9 = phi i32 [ %20, %19 ], [ 0, %11 ] > indirectbr i8* %8, [label %4, label %19] > > %19: > %20 = add nsw i32 %9, 1 > %21 = icmp eq i32 %9, 9999 > br i1 %21, label %16, label %7 the br in %19 should be optimized to branch directly to itself rather than going

> Looks like your shared library is not being compiled with symbols. > Did you verify that your sources are compiled with -g? I think so, this is the makefile (based on the one in the Hello pass): > LEVEL = ../../.. > LIBRARYNAME = CGF > LOADABLE_MODULE = 1 > USEDLIBS = > > ifneq ($(REQUIRES_RTTI), 1) > ifneq ($(REQUIRES_EH), 1) > EXPORTED_SYMBOL_FILE =

> Are you loading the shared library directly from the build directory, > or are you installing it first? I'm invoking it directly, I guess:./opt -load=CGF.so -cgf -debug test.S should I install it? (I have no idea about how to do it, though...) > If you run "file CGF.so" on the file you actually load, does it say it > is stripped or non-stripped? cafxx at

> Try building with "make VERBOSE=1", which will show you the > command-lines passed to the compiler/linker. Post the output here. there you go: > cafxx at ubuntu:~/Projects/llvm2/lib/Transforms/cgf$ make VERBOSE=1 > llvm[0]: Compiling CGFPass.cpp for Debug+Asserts build (PIC) > if g++ -I/home/cafxx/Projects/llvm2/include >

Suppose I have a bb with N predecessors and N successors. What is, in your opinion, the best way to express that the bb has (dynamically) only one successor (i.e. if coming from the i-th predecessor we will always jump to the i-th successor)? b.r., -- Carlo Alberto Ferraris <cafxx at strayorange.com <mailto:cafxx at strayorange.com>> website/blog

On Jun 24, 2011, at 10:34 AM, Carlo Alberto Ferraris wrote: > >> Looks like your shared library is not being compiled with symbols. Did you verify that your sources are compiled with -g? > I think so, this is the makefile (based on the one in the Hello pass): >> LEVEL = ../../.. >> LIBRARYNAME = CGF >> LOADABLE_MODULE = 1 >> USEDLIBS = >> >>

Nella citazione martedì 2 agosto 2011 22:01:13, Carlo Alberto Ferraris ha scritto: > My question is: > what is the best way to > express such relationships in LLVM IR ("best" in the sense of allowing > other optimizations to run effectively)? Bear in mind that in this > example N=2, but it may be way bigger than that. Just to clarify: I already figured out two ways to