similar to: [LLVMdev] Box removal

In the creation of dynamic languages we often have to box values together. For instance, take the following expression: IntObj c = sqrt((a*a)+(b*b)); Here, most likely, a bytecode interpreter would execute this as "mul_ints", "add_ints", "sqrt", etc. Inside these primitive functions we would have to unwrap our IntObj types, add the values, allocate a new object and

On Mon, Oct 17, 2011 at 7:58 AM, James Molloy <james.molloy at arm.com> wrote: > Hi, > > > > Looking at bugzilla PR11087, I’d like to conditionalise a transformation in > ARMIselLowering.cpp based on whether we’re compiling for codesize or > performance. > > > > -Os doesn’t actually exist for llc, and I can’t see an obvious place where > that condition

2009/8/2 Richard Pennington <rich at pennware.com>: > Eli Friedman wrote: >> 2009/8/2 Richard Pennington <rich at pennware.com>: >>> The following fails on x86_64 because of the output constraint '0'. >>> My question is, is this legal. LLVM complains about the size difference >>> (32 vs 64), but it is the same register (ax). >>>

Eli Friedman wrote: > 2009/8/2 Richard Pennington <rich at pennware.com>: >> The following fails on x86_64 because of the output constraint '0'. >> My question is, is this legal. LLVM complains about the size difference >> (32 vs 64), but it is the same register (ax). >> Works on x86. >> >> %42 = call i64 asm sideeffect

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 `Storage.hasVal' failed. static bool eliminateStrlen(CallInst *CI, BasicBlock::iterator &BBI, AliasAnalysis *AA, MemoryDependenceResults

It looks like the memoryIsNotModifiedBetween assumes the second argument is a store, or some other instruction supported by MemoryLocation::get.  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

"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, ...) (2) GetUnderlyingObject would give me Value * (from malloc) ? Also another case: memset(s, 0, len); // len > 1 return strlen(s); // optimize to 0 (3)

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* >

memoryIsNotModifiedBetween is precisely the sort of expensive walk we shouldn't be doing... I'm surprised it hasn't caused any serious issues yet.  Ideally, what we should be doing is using MemorySSA to find a dependency from 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

Yeah, sorry for that. Better "It compiles ok (but maybe incorrect code)", not "It works" as I wrote. 2018-05-23 1:08 GMT+02:00 Friedman, Eli <efriedma at codeaurora.org>: > You might want to look more carefully at how you're constructing the > MemoryLocation. The first argument is a pointer, and the second argument > is the number of bytes pointed to by

* 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

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 arguments: opt aaa.ll -dse -S 1. Running pass 'Function Pass Manager' on module 'aaa.ll'. 2. Running pass 'Dead Store Elimination' on function

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, BasicBlock::iterator &BBI, AliasAnalysis *AA, MemoryDependenceResults *MD, const DataLayout &DL, const TargetLibraryInfo *TLI,

It works 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

You might want to look more carefully at how you're constructing the MemoryLocation.   The first 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

On Fri, Jun 6, 2008 at 9:29 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Fri, Jun 6, 2008 at 6:32 AM, Tomas Lindquist Olsen > <tomas.l.olsen at gmail.com> wrote: >> Hi all, >> >> I'm having some trouble with inline asm expressions, more specifically >> how to create the right FunctionType for a given constraint set. >> So far it has

2009/8/2 Richard Pennington <rich at pennware.com>: > The following fails on x86_64 because of the output constraint '0'. > My question is, is this legal. LLVM complains about the size difference > (32 vs 64), but it is the same register (ax). > Works on x86. > > %42 = call i64 asm sideeffect "syscall\0A\09", >

On Fri, Jun 6, 2008 at 6:32 AM, Tomas Lindquist Olsen <tomas.l.olsen at gmail.com> wrote: > Hi all, > > I'm having some trouble with inline asm expressions, more specifically > how to create the right FunctionType for a given constraint set. > So far it has worked well for inputs, but not for outputs. The inline > asm support in this language (which is D, LLVMDC[1]) is

Hi James, So does this mean if the instruction could set the overflow flag, the instruction should not have [(set ... )] in it's pattern, i see this is the difference in instruction description for the mips case. I'm wondering how llvm knows when to use certain compare instructions such as SETNE or SETUNE? And for sign or zero extending loads? I can see the PatFrags described and the

Hi Sam, I am not a MIPS expert by any means, so YMMV, but: MIPS addu only differs to "add" in its (non)setting of the overflow flag. Because LLVM doesn't provide a way via the IR to access the overflow flag, a special notation isn't required in the IR to distinguish the two operations. Do you have another example? Cheers, James -----Original Message----- From: