search for: ipsccp

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 i32 @bar(i32 %n) { entry: store i32 1, i32* @g br label %loop loop...

...ehalf, please let us know. > > -Hal > On 7/10/20 9:04 PM, Fangqing Du via llvm-dev wrote: > > 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 i32 @bar(i32 %...

...r, i32 0, i32 0)) nounwind %c = icmp eq i8* %p, getelementptr ([1 x i8]* @str, i32 1, i32 0) br i1 %c, label %pass, label %fail fail: tail call void @abort() noreturn nounwind unreachable pass: ret i32 0 } declare void @abort() appears to be mis-optimised by "opt -ipsccp" into this: define internal i8* @f(i8* %p) nounwind readnone { ret i8* undef } define i32 @main() nounwind { %p = call i8* @f(i8* getelementptr ([1 x i8]* @str, i32 0, i32 0)) nounwind br label %fail fail: tail call void @abort() noreturn nounwind unreachable }...

...ive more opportunities for >> optimization. >> But we shouldn't depend on 'attributor' to correct wrong function >> attributes, because we cannot run 'attributor' after every pass, right? > > Correct. Each pass must be correct on its own. We need to fix ipsccp. > I don't think that was ever questioned ;) I think the comment about the Attributor was more to show that this behavior is not the same there which is yet another good indicator this is a bug. ~ Johannes >  -Hal > > >> >> Thanks, >> Fangqing >> >&g...

Sean Silva via llvm-dev <llvm-dev at lists.llvm.org> writes: > No tests fail with the patch below, so I would say it's pretty useless. It > seems that the C bindings are the only user but we can probably just have them > return IPSCCP instead. I don't necessarily think your conclusion is wrong, but the patch isn't proving what you think it's proving. In fact, the below passes all tests as well. When you call passes through `opt` they don't end up calling through the createXYZPass path. diff --git a/lib/Transfor...

The pass is pretty rudimental (as the comment at the top of the file hints), and it seems LLVM already has IPSCCP (which should do a better job at interprocedural constant propagation). I'm also not entirely sure it's used anywhere. Is there any reason to keep it around? Thanks, -- Davide "There are no solved problems; there are only problems that are more or less solved" -- Henri Poincar...

...tice values >> calculated by SCCP. Should I split the current SCCP optimization into an >> analysis piece and the optimization that depends on it, so that I can >> use its analysis results? > > SCCP is already split into an SCCPSolver class that is used by the SCCP > and IPSCCP classes. You should just be able to use SCCPSolver. Note > that it is not a pass, just a class you can use. Thanks. I thought SCCPSolver was just a helper. I suppose then I should just move its class declaration into a header so it can be seen from outside SCCP.cpp. Would creating a new inclu...

...pass or the generated code? I imagine all passes which either removes data or add attributes are included in this list, plus some simplification passes: -adce -argpromotion -constmerge -constprop -deadargelim -dse -functionattrs -globaldce -globalopt -gvn -instcombine -internalize -ipconstprop -ipsccp -licm -prune-eh -sccp Also, is there any redundant pass in this list (things line sccp/ipsccp)?

...; calculated by SCCP. Should I split the current SCCP optimization into an >>> analysis piece and the optimization that depends on it, so that I can >>> use its analysis results? >> >> SCCP is already split into an SCCPSolver class that is used by the SCCP >> and IPSCCP classes. You should just be able to use SCCPSolver. Note >> that it is not a pass, just a class you can use. > > Thanks. I thought SCCPSolver was just a helper. I suppose then I should > just move its class declaration into a header so it can be seen from > outside SCCP.cpp. Wou...

...e of padding when an aggregate value is stored into memory, and I'd like to suggest that storing an aggregate fills padding with undef. Here are a few clues that supports this change: - According to C17, the value of padding bytes when storing values in structures or unions is unspecified. - IPSCCP ignores padding and directly stores a constant aggregate if possible: https://godbolt.org/z/ddWq9z Memcpyopt ignores padding when copying an aggregate or storing a constant: https://godbolt.org/z/hY6ndd / https://godbolt.org/z/3WMP5a - Alive2 (with store operation updated) did not find any problem...

Hi, As far as I know, the ipconstprop pass has not been actively used in years and ipsccp has been used instead. This has the potential for confusion and sometimes leads people to spend time finding & reporting bugs as well as updating it to work with the latest API changes. If there are people actively using it, I would love to hear. If no-ones using it, I’d propose to remove the...

...CCP optimization >>>> into an >>>> analysis piece and the optimization that depends on it, so that I can >>>> use its analysis results? >>> >>> >>> SCCP is already split into an SCCPSolver class that is used by the SCCP >>> and IPSCCP classes. You should just be able to use SCCPSolver. Note >>> that it is not a pass, just a class you can use. >> >> >> Thanks. I thought SCCPSolver was just a helper. I suppose then I should >> just move its class declaration into a header so it can be seen from &...

Hi, On Sat, Sep 5, 2009 at 9:12 PM, Sanjiv Gupta<sanjiv.gupta at microchip.com> wrote: > Is the patch below ok? > > Index: LLVMCConfigurationEmitter.cpp > =================================================================== > --- LLVMCConfigurationEmitter.cpp    (revision 80668) > +++ LLVMCConfigurationEmitter.cpp    (working copy) > @@ -1141,6 +1141,7 @@ >          

Hello Alexander, > Interesting topic. Is any such optimization reachable from C? Yes, I think so - both PassBuilder and PassManagerBuilder add MemCpyOpt & IPSCCP in the default pass pipeline. Juneyoung On Wed, Aug 19, 2020 at 8:43 PM Alexander Cherepanov <ch3root at openwall.com> wrote: > On 19/08/2020 06.05, Juneyoung Lee via llvm-dev wrote: > > LangRef isn't clear about the value of padding when an aggregate value is > > stored...

...d better luck compiling all of pymol 1.1r2 with > -O4 on darwin9. Everythink links and there appears to be > no regressions in the resulting code. I take it that LTO > in llvm 2.5 is still limited to dead code elimination, > correct? No. libLTO does the equivalent to opt -internalize -ipsccp -globalopt -constmerge -deadargelim -instcombine -inline -prune-eh -globaldce -argpromotion -instcombine -jump-threading -scalarrepl -globalsmodref-aa -licm -gvn -memcpyopt -dse -instcombine -jump-threading -mem2reg -simplifycfg -globaldce Will LTO ever be extended to inlining across > fi...

I've had better luck compiling all of pymol 1.1r2 with -O4 on darwin9. Everythink links and there appears to be no regressions in the resulting code. I take it that LTO in llvm 2.5 is still limited to dead code elimination, correct? Will LTO ever be extended to inlining across files as well as constant-folding and global data allocation optimizations? Or does the reliance on gcc-4.2 as the

On 10/26/2017 10:56 PM, Chris Lattner via llvm-dev wrote: > >> On Oct 26, 2017, at 8:14 PM, Chandler Carruth via llvm-dev >> <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> >> >> One alternative that seems appealing but doesn't actually help would >> be to make `TargetLibraryInfo` ignore internal functions. That is

...f getting the opt -O3 multi-step to match the clang -O3 result. Any thoughts or insights are appreciated. Below is a sorted list of the flags missing from each for completeness. not contained in 1pass O3 (count=18) -aa-scalar-evolution -always-inline -callsite-splitting -inject-tli-mappings -ipsccp -jump-threading-correlated-propagation -livedebugvalues -loops-loop-simplify -memdep-lazy-branch-prob -openmpopt -opt-remark-emitter-instcombine -regallocfast -speculative-execution -stackmap-liveness -tbaa-scoped-noalias -vector-combine -verify -write-bitcode not contained in multi O...

...w is a sorted list of the >> flags missing from each for completeness. >> >> not contained in 1pass O3 (count=18) >> >> -aa-scalar-evolution >> >> -always-inline >> >> -callsite-splitting >> >> -inject-tli-mappings >> >> -ipsccp >> >> -jump-threading-correlated-propagation >> >> -livedebugvalues >> >> -loops-loop-simplify >> >> -memdep-lazy-branch-prob >> >> -openmpopt >> >> -opt-remark-emitter-instcombine >> >> -regallocfast >> >&...

...cally the original C source code built with `clang -O0 -S -emit-llvm`, followed by running `opt -mem2reg`). There’s a patch under review that adds support for conditional range propagation ( https://reviews.llvm.org/D76611) and with the patch it can be simplified to the code below by running `opt -ipsccp -simplifycfg -instcombine` > > define i32 @test(i32 %0) { > %.off = add i32 %0, -16 > %2 = icmp ult i32 %.off, 12 > %spec.select = select i1 %2, i32 66, i32 45 > ret i32 %spec.select > } > > > The reason it does not yet work in the default pipeline is that the...