similar to: [LLVMdev] constant propagation pass

Why in the webpage http://llvm.org/docs/Passes.html some of the passes such as "correlated value propagation" or "early cse" are not described? Am I missing some other webpage with these informations? Thank you in advance, Niko -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hi all, I wrote 2 passes and I want to make run llvm run the passes in this order: -mem2reg -load=…/mypass1.dylib -mypass1 -load=…/mypass2.dylib -mypass2 -O1 -O2 -O3 I know I can do this by manually passing them as an argument to opt. Is there any way to force this sequence directly from clang? I am asking this because I am trying to compile a program and I can specify in the ./configure

On Oct 5, 2013, at 9:17 PM, Niko Zarzani <koni10 at hotmail.it> wrote: > Hi all, > > I wrote 2 passes and I want to make run llvm run the passes in this order: > -mem2reg -load=…/mypass1.dylib -mypass1 -load=…/mypass2.dylib -mypass2 -O1 -O2 -O3 > > I know I can do this by manually passing them as an argument to opt. > > Is there any way to force this sequence

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

Hi all, I am trying to see how single llvm optimizations work by running them one by one with opt and looking how the IR changes.Since I was interested in seeing how constant propagation was working I tried to run opt on the Sparse Conditional Constant Propagation, however by passing as argument -S -sccp -die it does not change anything in the output IR code. I attached the file with the source

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 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

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

On Fri, Jul 15, 2011 at 12:21 AM, Martin Apel <martin.apel at simpack.de> wrote: > Hi all, > > I stumbled across a peculiarity regarding constant propagation that I don't understand. I'm not sure, if I oversee anything or if it's a missing feature. > > I have created the following simple test function in C: > > int times_zero(int a) > { >  return (a *

Hi Yunming, On 28/03/13 03:15, yunming zhang wrote: > Hi, > > I just started working with llvm, I am trying to test and improve the constant > propagation pass (-constprop), > > I have two main questions, > > 1. I wrote my own test file, which has something like > int a = 1 > int b = a + 2; > int c = b + 3; > print c > > However, non

Hi all, I stumbled across a peculiarity regarding constant propagation that I don't understand. I'm not sure, if I oversee anything or if it's a missing feature. I have created the following simple test function in C: int times_zero(int a) { return (a * 0); } Compiling this with GCC using dragonegg generates the following code: %int = type i32 define i32 @times_zero(i32 %a)

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

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

Hi, I just started working with llvm, I am trying to test and improve the constant propagation pass (-constprop), I have two main questions, 1. I wrote my own test file, which has something like int a = 1 int b = a + 2; int c = b + 3; print c However, non of the instruction was killed according to -stat. I think it might due to the fact the llvm instructions generated was a bit

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

Hi Seb, > I'm writting following LLVM assembly: > > ; ModuleID = 'structaccess.ll' > not having a data layout string in your module disables many optimizations. Ciao, Duncan. > %struct._anon0 = type <{ i32, i32, i32 }> > > @s = common global %struct._anon0 zeroinitializer > > define arm_aapcscc void @foo() nounwind { > L.entry: > store i32

Hi, I used the following commands on the program attached below: llvm-gcc --emit-llvm main.c -c -o main.bc opt -ipconstprop main.bc -o main1.bc diff main.bc main1.bc no difference was o/p :( The Program Segment is as shown below: #include <stdio.h> void f1(int a) { a=a+1; printf("%d",a); } void f2() { int b; b=1; f1(b); } int main() { int

Hi all, I'm writting following LLVM assembly: ; ModuleID = 'structaccess.ll' %struct._anon0 = type <{ i32, i32, i32 }> @s = common global %struct._anon0 zeroinitializer define arm_aapcscc void @foo() nounwind { L.entry: store i32 5, i32* getelementptr inbounds (%struct._anon0* @s, i32 0, i32 0) store i32 10, i32* getelementptr inbounds (%struct._anon0* @s, i32 0, i32 1)