search for: bolvanský

Use *last = nullptr; for (Use &U : Src->uses()) last = &U; last->getUser()->dump(); Or any better solution? 2018-04-20 19:19 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > Is: > > > 2018-04-20 18:07 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > >> Hello, >> >> Code: https://godbolt.org/g/EG4Wi6 >> >> unsigned fff3(void) { >> char buf[10] = ""...

Maybe nicer.. auto i = Src->uses().begin(); std::advance(i, Src->getNumUses() - 1); i->getUser()->dump(); 2018-04-20 19:19 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > Use *last = nullptr; > for (Use &U : Src->uses()) > last = &U; > last->getUser()->dump(); > > > Or any better solution? > > 2018-04-20 19:19 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com&g...

...argument is a pointer, and the second argument is the number of bytes pointed to by that pointer (or MemoryLocation::UnknownSize if the number of bytes accessed isn't known). More generally, copy-pasting code you don't understand isn't a good idea. -Eli On 5/22/2018 4:02 PM, Dávid Bolvanský wrote: > IR: > define i32 @calloc_strlen_write_between() { >   %call = tail call noalias i8* @calloc(i32 10, i32 1) >   store i8 97, i8* %call, align 1 >   %call1 = tail call i32 @strlen(i8* %call) >   ret i32 %call1 > } > > > static bool eliminateStrlen(CallInst *CI,...

...rgument > is the number of bytes pointed to by that pointer (or > MemoryLocation::UnknownSize if the number of bytes accessed isn't known). > > More generally, copy-pasting code you don't understand isn't a good idea. > > -Eli > > > On 5/22/2018 4:02 PM, Dávid Bolvanský wrote: > > IR: > define i32 @calloc_strlen_write_between() { > %call = tail call noalias i8* @calloc(i32 10, i32 1) > store i8 97, i8* %call, align 1 > %call1 = tail call i32 @strlen(i8* %call) > ret i32 %call1 > } > > > static bool eliminateStrlen(CallInst...

...with MemoryLocation MemoryLocation::get(const CallInst *CI) { AAMDNodes AATags; CI->getAAMetadata(AATags); const auto &DL = CI->getModule()->getDataLayout(); return MemoryLocation(CI, DL.getTypeStoreSize(CI->getType()), AATags); } Is it fine? :) 2018-05-22 23:56 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > Looks like there are many overloads for "get". http://llvm.org/ > doxygen/MemoryLocation_8cpp_source.html > > But nothing for CallInst. Any suggestions how to do a proper one? I will > look at it too. > > 2018-05-22 23:34 GMT+...

...placeAllUsesWith(Len); CI->eraseFromParent(); return true; } return false; } ------------------------------------------------------ That IR is still wrongly transformed with this code to ret i32 0 (but there is write between calloc and strlen). Any suggestions? 2018-05-23 0:49 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > It works with > > MemoryLocation MemoryLocation::get(const CallInst *CI) { > AAMDNodes AATags; > CI->getAAMetadata(AATags); > const auto &DL = CI->getModule()->getDataLayout(); > > return MemoryLocation(CI, DL.getTypeSto...

..., you'll have to compute the MemoryLocation > some other way. > > (Generally, if you're asking a question about an assertion, please include > the whole stack trace; it's hard to guess what's happening otherwise.) > > -Eli > > > On 5/22/2018 2:16 PM, Dávid Bolvanský wrote: > > * if (isStringFromCalloc(Dst, TLI)) should be if > (!isStringFromCalloc(Dst, TLI)) > but still asserting... > > 2018-05-22 23:06 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > >> Can you help a bit? >> >> I try to work with DSE b...

...dummy asm(“”): #define likely(x) __builtin_expect((x),1) // switch like char * b(int e) { if (likely(e == 0)) return "0"; asm(""); if (e == 1) return "1"; else return "f"; } Dave > On May 9, 2018, at 2:33 PM, Dávid Bolvanský via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > I did > https://bugs.llvm.org/show_bug.cgi?id=37368 <https://bugs.llvm.org/show_bug.cgi?id=37368> > > 2018-05-09 20:33 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com <mailto:david.bolvansky at gmail.c...

Looks like there are many overloads for "get". http://llvm.org/doxygen/MemoryLocation_8cpp_source.html But nothing for CallInst. Any suggestions how to do a proper one? I will look at it too. 2018-05-22 23:34 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > Full stack trace: > > opt: /home/xbolva00/LLVM/llvm/include/llvm/ADT/Optional.h:176: T* > llvm::Optional<T>::getPointer() [with T = llvm::MemoryLocation]: > Assertion `Storage.hasVal' failed. > Stack dump: > 0. Program argumen...

* if (isStringFromCalloc(Dst, TLI)) should be if (!isStringFromCalloc(Dst, TLI)) but still asserting... 2018-05-22 23:06 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > Can you help a bit? > > I try to work with DSE but I got the following assert: > opt: /home/xbolva00/LLVM/llvm/include/llvm/ADT/Optional.h:176: T* > llvm::Optional<T>::getPointer() [with T = llvm::MemoryLocation]: > Assertion `Storag...

...If you're passing in something else, you'll have to compute the MemoryLocation some other way. (Generally, if you're asking a question about an assertion, please include the whole stack trace; it's hard to guess what's happening otherwise.) -Eli On 5/22/2018 2:16 PM, Dávid Bolvanský wrote: > * if (isStringFromCalloc(Dst, TLI)) should be if > (!isStringFromCalloc(Dst, TLI)) > but still asserting... > > 2018-05-22 23:06 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com > <mailto:david.bolvansky at gmail.com>>: > > Can you help a b...

I did https://bugs.llvm.org/show_bug.cgi?id=37368 2018-05-09 20:33 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > I did > > https://bugs.llvm.org/show_bug.cgi?id=37368 > > 2018-05-09 20:29 GMT+02:00 David Zarzycki <dave at znu.io>: > >> I’d wager that the if-else chain is being converted to a "switch >> statement” during an opti...

Hello, #define likely(x) __builtin_expect((x),1) // switch like char * b(int e) { if (likely(e == 0)) return "0"; else if (e == 1) return "1"; else return "f"; } GCC correctly prefers the first case: b(int): mov eax, OFFSET FLAT:.LC0 test edi, edi jne .L7 ret But Clang seems to ignore _builtin_expect hints in this case.

...the memset: if the closest dependency is the malloc, there aren't any stores between the memset and the malloc.  (But we aren't using MemorySSA in DSE yet; see https://reviews.llvm.org/D40480.) But yes, memoryIsNotModifiedBetween has the right meaning. -Eli On 5/21/2018 7:48 AM, Dávid Bolvanský wrote: > "memory accesses between the malloc and the memset without an > expensive linear scan of the block/function" > > (1) do you mean just use "memoryIsNotModifiedBetween" function in DSE > to check it? > > x = maloc(..); > memset(x, ...) > >...

...n printf every time we call it. We would just replace string constant "%s: %s" with "ABC: %s" and possibly orphaned "ABC" constant could be removed completely. 2018-05-22 18:36 GMT+02:00 Hal Finkel <hfinkel at anl.gov>: > > On 05/22/2018 10:42 AM, Dávid Bolvanský wrote: > > Thanks. > > Yes, to substitute only some of the arguments. Formatting used by printf > depends on the locale but only for double, float types I think - yes, I > would not place double/float constants into the format string. > > > Okay. I think it's true th...

...) > > // switch like > char * b(int e) { > if (likely(e == 0)) > return "0"; > asm(""); > if (e == 1) > return "1"; > else return "f"; > } > > Dave > > On May 9, 2018, at 2:33 PM, Dávid Bolvanský via llvm-dev < > llvm-dev at lists.llvm.org> wrote: > > I did > https://bugs.llvm.org/show_bug.cgi?id=37368 > > 2018-05-09 20:33 GMT+02:00 Dávid Bolvanský <david.bolvansky at gmail.com>: > >> I did >> >> https://bugs.llvm.org/show_bug.cgi?id=37368...

...s the malloc, there > aren't any stores between the memset and the malloc. (But we aren't using > MemorySSA in DSE yet; see https://reviews.llvm.org/D40480.) > > But yes, memoryIsNotModifiedBetween has the right meaning. > > -Eli > > > On 5/21/2018 7:48 AM, Dávid Bolvanský wrote: > > "memory accesses between the malloc and the memset without an expensive > linear scan of the block/function" > > (1) do you mean just use "memoryIsNotModifiedBetween" function in DSE to > check it? > > x = maloc(..); > memset(x, ...) > &...

...2018 o 9:53 David Blaikie <dblaikie at gmail.com> napísal(a): > > > On Fri, Sep 14, 2018 at 12:48 AM Stephan Bergmann <sbergman at redhat.com> > wrote: > >> On 13/09/2018 18:22, David Blaikie via llvm-dev wrote: >> > On Thu, Sep 13, 2018 at 12:13 AM Dávid Bolvanský via llvm-dev >> > <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> > >> /home/davidbolvansky/trunk/llvm/unittests/ExecutionEngine/Orc/CompileOnDemandLayerTest.cpp:79:40: >> >> > required from here >> > &gt...

On 05/22/2018 11:59 AM, Dávid Bolvanský wrote: > It could save useless parsing in s/f/printf during runtime. Sure. But it is not clear that matters. printf is expensive anyway. Maybe this matters more for snprintf? Have you benchmarked this? > > E.g. for heavy "fprint"ing code like fprintf(f, "%s: %s", TAG...

Hello, I would like to find a way to do this removal properly. I found DSE and "eliminateNoopStore" can be useful for this thing. What I mean? int *test = malloc(15 * sizeof(int)); test[10] = 12; < ----- remove this store memset(test,0,sizeof(int) * 15); I already checked the function "eliminateNoopStore". Looks good, I think I would be to get the value ("A") we