similar to: [LLVMdev] static variables in the IR

Hi All, I have a question on ConstantExpressions and llvm intrinsic memcpy/memset/memmove. I am using llvm-2.8 release. In one of the C programs that I am compiling using clang frontend, the call to memcpy instrinsic looks like the following call void @llvm.memcpy.p0i8.p0i8.i64(i8* %tmp2, i8* bitcast (%struct.ta* @tret to i8*), i64 4, i32 4, i1 false), !dbg !19 The second argument to memcpy is

>> Agreed. If ld64 can drop support for .o produced by the old gcc that >> would be awesome. Failing that, what is really needed is > Because of static archives, the linker has to support old .o files for quite a while. I also don’t know when clang starting getting this right. r123585 (Jan 16 17:19:34 2011) I think. > Also, this seems like linker complexity for a very

On 4/14/11 6:34 PM, Kodakara, Sreekumar V wrote: > > Hi All, > > I have a question on ConstantExpressions and llvm intrinsic > memcpy/memset/memmove. I am using llvm-2.8 release. In one of the C > programs that I am compiling using clang frontend, the call to memcpy > instrinsic looks like the following > > call void @llvm.memcpy.p0i8.p0i8.i64(i8* %tmp2, i8* bitcast

On Tue, Apr 4, 2017 at 12:36 PM, Duncan P. N. Exon Smith < dexonsmith at apple.com> wrote: > > On 2017-Apr-04, at 12:12, Peter Collingbourne <peter at pcc.me.uk> wrote: > > On Mon, Apr 3, 2017 at 8:13 PM, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> >> On Apr 3, 2017, at 7:08 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: >>

On Mon, Oct 22, 2012 at 9:33 PM, Niko Zarzani <koni10 at hotmail.it> wrote: > Thank you, it was what I really was searching for :) > > However, I don't know if I well understood. I've find this link in the > second link which seemed what i was looking for: > http://nondot.org/sabre/LLVMNotes/BuiltinUnreachable.txt . > If I put around the code block (inside my

Thank you, it was what I really was searching for :) However, I don't know if I well understood. I've find this link in the second link which seemed what i was looking for: http://nondot.org/sabre/LLVMNotes/BuiltinUnreachable.txt .If I put around the code block (inside my function with precondition (x>0 && y>0)) a contruct like that that use __builtin_unreachable: int foo(int

Hi Niko, Do you mean branch prediction, i.e. __builtin_expect [1]? Many compilers support it, I think clang (LLVM's C/C++ frontend) is among them. - D. [1] http://gcc.gnu.org/onlinedocs/gcc/Other-Builtins.html 2012/10/23 Niko Zarzani <koni10 at hotmail.it>: > Hi all, > Is there any way to tell LLVM some additional information about the > variables in the code in order to

Hello. I'm posting this question here, because there seem to be no LLD-specific mailing list. Sorry in advance if this is wrong one. I compile two C source with following command: clang -flto -o %name.bc %name.c LLVM is augmented with my custom pass, which amongst other things create a global with appending linkage: @myvar = appending constant [1 x [1 x i8]*] ... I also have another pass

Hey Duncan, Thanks! I figured out this piece of code finally: Value *gep = call->getArgOperand(0); if ( ConstantExpr *pCE = dyn_cast<ConstantExpr>(gep) ) { Value *firstop = pCE->getOperand(0); if (GlobalVariable *GV = dyn_cast<GlobalVariable>(firstop)){ Constant *v = GV->getInitializer(); if

You may want to check this out: http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-October/053924.html and also http://llvm.org/PR810 - xi On 10/22/12 6:05 PM, Niko Zarzani wrote: > Hi all, > Is there any way to tell LLVM some additional information about the > variables in the code in order to make better optimization? > For example, if my function has a certain precondition (such

In the following IR module: – define i8 @foo() #0 { entry: %call0 = call i8 @bar() ret i8 %call0 } declare i8 @bar() #1 – @bar() gets marked as its own user in top-of-tree LLVM. I patched the Verifier to check it (but didn’t commit the patch): – Index: lib/IR/Verifier.cpp =================================================================== --- lib/IR/Verifier.cpp (revision 203468) +++

Hi all,Is there any way to tell LLVM some additional information about the variables in the code in order to make better optimization?For example, if my function has a certain precondition (such as x>0) then it will be possible to better optimize the code given that information (which the compiler does not know).I am new in this field and I don't know if there are ways to tell the compiler

I tried it on a simple file test.c (as you did) but actually clang does not show me any output. In addition I tried to set the CFLAGS specifying the -mllvm -time-passes options. However I still have anything about the time passes informations in the output and I also get this warning during the build with make:clang: warning: argument unused during compilation: '-mllvm -time-passes'Maybe

On 19 September 2014 15:54, Steven Wu <stevenwu at apple.com> wrote: > Yes, we don’t need to edit the assembly in the file, but we need to modified the CHECK line to reflect the output of current llvm-dis. I was talking about updating the CHECK in all the previous version. Does that make sense? Yes, the CHECK lines would have to be updated, but that seems like a pretty small annoyance.

Hi, When I’m compiling a code with –fvisibility=hidden –fPIC for ARM, I find that LLVM generates less optimized code than GCC. For example: test.cpp: void init(void *); int g0[100]; int g1[100]; int g2[100]; void foo() { init(&g0); init(&g1); init(&g2); } Clang will emit 1 GOT entry for each GV and 2 instructions to get the address: ldr

To use options like "-time-passes" and "-stats" you need to prefix them with "-mllvm": clang -mllvm -time-passes -O3 test.c -o /dev/null Note that I believe you need asserts enabled or some other build configuration for this to work, the timing code is disabled in fully release builds IIRC. Hope this helps! ~Will On Thu, Sep 12, 2013 at 11:50 AM, Niko Zarzani

This compiler does not have mem-SSA, as far as I know, only few pass can propagate value along memory. You need to promote those local variable into register first before sccp is invoked. e.g1. opt a.ll -basicaa -gvn -sccp -S eg.2. opt a.ll -sroa -sccp -S On 4/16/13 12:37 PM, Niko Zarzani wrote: > Hi all, > > I am trying to see how single llvm optimizations work by running them

Here is my code, (GV is a GlobalVariable*): GV = new GlobalVariable(AI->getType(), false, GlobalValue::InternalLinkage, 0, "temp_glob", &M); I tell it to make it with internal linkage, but when I run the pass it makes them external: %temp_glob = external global [10 x int]* ; <[10 x int]**> [#uses=2] %temp_glob = external global [10 x float]* ;

Hi all, I was interested in knowing which of the passes spends the most of the time compiling the dns server BIND.With the -CC option I selected clang as my compiler and, as I was expecting, the compilation gave me no problems.Now I have a question, is there any way to set an option similiar to "-time-passes" to clang in order to get those information I was interested in?Or do you think

I am trying to generate LLVM code that references a global array. Unfortunately, while I am generating the code I do not know the final length of the array, as I add elements to it as my compiler goes along. What is the best way to do this in LLVM? Ideally, I would be able to define the GlobalVariable array and change its length later on. I would love for it to have the correct length so I