similar to: flags to reproduce clang -O3 with opt -O3

Awesome, thanks! I'd like to have the last step (llc in your example) not perform additional optimization passes, such as O3, and simply use the O3 pass from opt in the previous line. Do you happen to know if I should use 'llc -O0 foo_o.bc -o foo.exe' instead to achieve this? On Thu, Jul 2, 2020 at 6:35 PM Mehdi AMINI <joker.eph at gmail.com> wrote: > > > On Thu,

Does LLVM have loop multiversioning ? it seems it does not with clang++ -O3 -mllvm -debug-pass=Arguments program.c -c bash-4.1$ clang++ -O3 -mllvm -debug-pass=Arguments fast_algorithms.c -c clang-3.6: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated Pass Arguments: -datalayout -notti -basictti -x86tti -targetlibinfo -no-aa -tbaa -scoped-noalias

Thanks again. I executed the following command line llc -O3 comb.ll.bc -debug-pass=Arguments and got Pass Arguments: -targetdata -targetpassconfig -no-aa -tbaa -targetlibinfo -basicaa -collector-metadata -machinemoduleinfo -machine-branch-prob -preverify -domtree -verify -loops -loop-simplify -scalar-evolution -loop-simplify -iv-users -loop-reduce -gc-lowering -unreachableblockelim

Hi, > I executed the following command line > > llc -O3 comb.ll.bc -debug-pass=Arguments > > and got > > Pass Arguments: -targetdata -targetpassconfig -no-aa -tbaa > -targetlibinfo -basicaa -collector-metadata -machinemoduleinfo > -machine-branch-prob -preverify -domtree -verify -loops -loop-simplify > -scalar-evolution -loop-simplify -iv-users -loop-reduce

Hi, On 12/06/12 13:09, Abdul Wahid Memon wrote: > Thanks alot. How can we view those optimization which are enabled when we do > > llc -O3 comb.ll llc -O3 comb.ll -debug-pass=Arguments > > Are these the same as the ones produced by the following command line no, as I mentioned before they are of a completely different nature to the optimizations that opt does. Ciao, Duncan.

Thanks alot. How can we view those optimization which are enabled when we do llc -O3 comb.ll Are these the same as the ones produced by the following command line llvm-as < /dev/null | opt -O3 -disable-output -debug-pass=Arguments Regards Shahzad On Tue, Jun 12, 2012 at 1:01 PM, Duncan Sands <baldrick at free.fr> wrote: >> Yes. But how exactly code generation (optimized one)

Thank you Hal and Stefan! Bug report is filed: https://bugs.llvm.org/show_bug.cgi?id=46717 And Stefan, I think 'attributor' is a really nice pass, and can infer more precise and useful attributes, which may give more opportunities for optimization. But we shouldn't depend on 'attributor' to correct wrong function attributes, because we cannot run 'attributor' after

On 7/14/20 4:34 PM, Hal Finkel via llvm-dev wrote: > > On 7/14/20 11:28 AM, Fangqing Du wrote: >> Thank you Hal and Stefan! >> >> Bug report is filed: https://bugs.llvm.org/show_bug.cgi?id=46717 >> <https://bugs.llvm.org/show_bug.cgi?id=46717> >> >> And Stefan, >> I think 'attributor' is a really nice pass, and can infer more >>

Hi all, Let's see an example (from Alexandre Isoard) first: **************************************************************************************** ; RUN: opt -ipsccp -deadargelim -licm -O2 -S < %s @g = internal global i32 0 ; Function Attrs: argmemonly define internal void @foo(i32* nonnull dereferenceable(4) %arg, i32 %val) #0 { entry: store i32 %val, i32* %arg ret void } define

Hello, I am trying to simplify the CFG of a given code and eliminate the conditionals, even though I will obtain codes that are not semantically equivalent. For example, given a simple loop: for(i=0; i<N; i++){    a[i] = i;     if (i%2==0)       a[i] += 12; } I would keep only the loop, without the if statement: for(i=0; i<N; i++){    a[i] = i; } I can eliminate such conditionals on

On Thursday 08 May 2008 18:33:48 Adrian Prantl wrote: > we noticed that llvmgcc4.2-2.2 sometimes generates non-natural loops > when compiling to bytecode without any optimizations. Apparently what > happens is that the loop header is duplicated, which results in two > entry points for the loop. this is actually a problem with the tailduplication pass of llvm. it does not consider

Hello everybody, we noticed that llvmgcc4.2-2.2 sometimes generates non-natural loops when compiling to bytecode without any optimizations. Apparently what happens is that the loop header is duplicated, which results in two entry points for the loop. Since this could obstruct subsequent loop optimizations, it might be interesting to further investigate this behavior. To show the problem, I have

We had some additional discussion on this. There is a lot of concern generally about post-RA passes which do not expect to have to handle virtual registers; specifically if they unexpectedly start seeing virtual registers, or if they work today but start making assumptions in the future. We discussed considering a mechanism that would require MachineFunctionPasses to "opt-in" and declare

I'm reading up on LLVM's implementation of tail duplication and the description is confusing: http://llvm.org/docs/Passes.html -tailduplicate: Tail Duplication This pass performs a limited form of tail duplication, intended to simplify CFGs by removing some unconditional branches. This pass is necessary to straighten out loops created by the C front-end, but also is capable of

Hi, while reading the TailDuplication pass, I found a check that looks rather pointless. TailDuplication looks at an unconditional branch instruction, BI. It performs a number of checks on the successor of this branch instruction, Dest. One of this checks is counting the number of predecessor. If this count is zero, Dest is regarded as dead and no tail duplication happens. However, as far as I

On Jun 11, 2008, at 6:27 AM, Florian Brandner wrote: > On Thursday 08 May 2008 18:33:48 Adrian Prantl wrote: >> we noticed that llvmgcc4.2-2.2 sometimes generates non-natural loops >> when compiling to bytecode without any optimizations. Apparently what >> happens is that the loop header is duplicated, which results in two >> entry points for the loop. > > this is

Here are 2 patches, which are independent of each other. The first splits PrologEpilogInserter into 2 parts : http://reviews.llvm.org/D16481 After looking at the code I thought it made more sense for the major split to include whether callee-saved register spills are supported. So for non-virtual targets, virtual registers are not supported and scavenging is optionally supported, and vice versa

Good morning! After updating and recompiling my copy of the LLVM trunk I noticed that the line "_passManager.add(llvm::createTailDuplicationPass());" in my code fails with the following assertion: Assertion failed: NormalCtor && "Cannot call createPass on PassInfo without default ctor!", file D:\Workspace\llvmtrunk\include\llvm/PassSupport.h, line 111 This behavior

We used to have an LLVM-IR pass did tail duplication (http://llvm.org/viewvc/llvm-project/llvm/tags/RELEASE_29/final/lib/Transforms/Scalar/TailDuplication.cpp) It was not used and went away with 3.0. The documentation is out of date. commit f940a1a869b4fe6f857e7fd8aeb97e7b7e9b390e Author: Rafael Espindola <rafael.espindola at gmail.com> Date: Tue Aug 30 23:03:45 2011 +0000 Remove the

Dear developers, I am trying to reproduce the results of applying opt -O3 to a source file in the form of LLVM IR. I want to get the same IR by manually ordering the passes used by O3 and passing them to opt. To illustrate what I am doing on an example, as an input I use linpack benchmark from the LLVM test suite[1]: 1. First I produce the intermediate representation using clang: clang -O3