similar to: How to call C function 'malloc' ?

Hi everyone, I am wondering what¹s stopping the LLVM optimizer (opt -O3) from eliminating the apparently useless « icmp sgt » instruction in the following piece of LLVM IR. > ; ModuleID = 'lambda-opt.bc' > target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" > target triple = "x86_64-apple-macosx10.10.0" > > ; Function

Here's a version that doesn't try to do block deletion on it's own. If you use -adce then -simplifycfg, you get what you want. It passes all tests except one, which is that we delete an invoke of a pure function, IE Transforms/ADCE/dce_pure_invoke.ll - I'm not sure why that's bad. The reason we delete it is because it returns false to I.mayHaveSideEffects(), and in particular,

> On 2015-May-15, at 13:15, Teresa Johnson <tejohnson at google.com> wrote: > > What isn't clear to me is what all uses the available > externally linkage type currently - do you happen to know? It's used for the `inline` keyword in the C language. If you do a `git grep available_externally -- test/` inside a clang checkout you might find some other uses. $ cat

Hello since my broad RFC request didn't catch any responses, let me get a bit more into the nitty-gritty: I tried to get llvm (3.7) to optimize superflous allocas away, but so far I haven't figured out how. Is there no optimizer for this ? Should I adorn something with some attributes ? As far as I can tell no, but I am no llvm expert... For what I want to do, i will probably have a

Caldarale, Charles R schrieb: > You have not provided us with the declaration for f(). Unless its argument is marked with the nocapture attribute, the compilation of g() cannot assume that f() has not retained a pointer to the x struct and is using it in the second call. > thanks a lot for the input. Yes, I forgot to that. The C function declaration would have been void f( struct a_b

Hi the appended IR code does not optimize to my liking :) this is the interesting part in x86_64, that got produced via clang -Os: --- movq -16(%r12), %rax movl -4(%rax), %ecx andl $2298949, %ecx ## imm = 0x231445 cmpq $2298949, (%rax,%rcx) ## imm = 0x231445 leaq 8(%rax,%rcx), %rax cmovneq %r15, %rax movl $2298949, %esi ## imm = 0x231445 movq %r12, %rdi movq %r14,

Hello Has there been any progress on this topic ? The 3.9 optimizer output is still the same as I just looked. https://llvm.org/bugs/show_bug.cgi?id=24448 Ciao Nat! Sanjay Patel schrieb: > [cc'ing Zia] > > We have this transform with -Os for some cases after: > http://reviews.llvm.org/rL244601 > http://reviews.llvm.org/D11363 > > but something in this example is

Since updating to LLVM 3.3, the system is generating attributes such as: attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false"

Hi, I've been working on a Blackfin backend (llvm-3.6.0) based on the previous one that was removed in llvm-3.1. llc generates codes like this: 29 p1 = r2; 30 r5 = [p1]; 31 p1 = r2; 32 r6 = [p1 + 4]; 33 r5 = r6 + r5; 34 r6 = [p0 + -4]; 35 r5 *= r6; 36 p1 = r2; 37 r6 = [p1 + 8]; 38 p1 = r2; p1 and r2 are in different register classes. A p*

On Fri, May 15, 2015 at 9:53 AM, Teresa Johnson <tejohnson at google.com> wrote: > On Fri, May 15, 2015 at 9:20 AM, David Blaikie <dblaikie at gmail.com> wrote: > > > > > > On Fri, May 15, 2015 at 9:18 AM, David Blaikie <dblaikie at gmail.com> > wrote: > >>> > >>> > >>> >> - Marking of imported functions (for use

Hi Jin, It's difficult to say just from looking at a pass, but one thing looked odd: > CallInst *call_print = CallInst::Create(call_print,paramArrayRef,"",ins_temp); This looks very dodgy. The "call_print" being used as an argument is the (uninitialised) one that's just been declared. This could be the source of the assertion failure (though a segfault is just as

Hi Mehdi, The ISO C specification does permit the math functions to modify ‘errno’, but I thought that the ‘-fno-math-errno’ option was to tell the optimiser to assume that ‘errno’ is not modified by the math functions. Explicitly providing ‘-fno-math-errno’ is not restoring the elision optimisation that was performed by LLVM v3.8, and this is really only a driver option, with ‘-fmath-errno’

Hi everyone, We are using the llvm2cpp feature of LLVM in the VMKit project and there are some issues that I would like to point out. I made a tiny reproducible example here, to be clear: echo "int main() { return 0; };" > test.c && clang test.c -emit-llvm -c -o - | llc -march=cpp -cppgen=function -cppfor=main -o - This command is supposed to generate the C++ code to

Hi LLVM developers, $ cat hello.c #include <stdio.h> void foo() { } int main(int argc, char *argv[]) {   for (int i = 0; i < 10; i++) {     printf("%d\n", i);   }   return 0; } $ /opt/llvm-svn/bin/clang --version Fedora clang version 6.0.0 (trunk 316308) (based on LLVM 6.0.0svn) Target: x86_64-redhat-linux Thread model: posix InstalledDir: /opt/llvm-svn/bin $

Hi, I wanted to know if it was possible to force ARM backend to compile a function in ARM while the rest is in Thumb mode. I tried the attributes which is used in GCC but it doesn't work. Here is what I tried: https://pastebin.com/jCr5LPUY Thanks in advance, Uvekilledkenny -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hello! clang defines some AttributeSet, for example: attributes #0 = { nounwind uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"="true" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "unsafe-fp-math"="false"

Can you send the IR you are using? Volkan On Thu, Oct 8, 2015 at 6:28 AM Erdem Derebaşoğlu < erdemderebasoglu at hotmail.com> wrote: > Thanks. I enabled my pass. I have one resolved issue though: > MachineMemOperand::getAddrSpace() always returns zero. How can I use it to > distinguish private memory accesses? > > Erdem > > ------------------------------ > From:

Hello, everyone! I want to write a pass which can insert a call "printf" instructions before every instruction in the LLVM IR. here is what I wrote: namespace { class call_print : public FunctionPass{ private: DenseMap<const Value*, int> inst_map; public: static char ID; call_print() : FunctionPass(ID){} //define a extern function "printf" static llvm::Function*

I'm trying to find a way to get/set the module attributes as printed in a module dump: attributes #0 = { noinline nounwind uwtable "correctly-rounded-divide-sqrt-fp-math"="false" "disable-tail-calls"="false" "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf"

Hi All, I need your guidance about a custom attribute. I have defined one for variables. It is accepted in the source code (without any warnings from clang), for example in following snippet. #define NEWATTR __attribute__((moviAttr(1))) int main() { NEWATTR volatile unsigned int a = 5; volatile unsigned int *p; p = &a; return (a+*p); } and actually when I Dump the declaration, after