similar to: In LLVM IR, how can I determine if a switch statement had an explicit default case?

On Wed, Mar 30, 2011 at 03:19, Julien Henry <Julien.Henry at imag.fr> wrote: > > Actually, I'm working on a static analyzer that computes invariants at > each basicBlock: "In basicBlock B, what is the set of possible > assignments for each live values ?" > and I obtains results such as "In B, we have 0 <= x <= 42" > Well, you have to find that

Hi, Are there some built-in LLVM transformation pass, or written library code that transforms LLVM::SwitchInst into if-condition statements (LLVM:: BranchInst)? The purpose of the transformation is that we have a legacy program analyzer that includes an LLVM pass manipulating if-condition statements. Statements of LLVM::SwithchInst should have been handled in the same manner but was not done.

I'm trying to figure out how to feed a blockaddress to a switch condition AND destination (basically emulating an indirectbr via a switch; I know it's not a good approach, I'm just experimenting). Suppose I have the following: SwitchInst *s = SwitchInst::Create(...); BasicBlock *bb = ...; PtrToIntInst k = new PtrToIntInst(BlockAddress::get(bb), <TYPE>, "", s);

>> The compiler remembers for debugging purpose that x is defined as >> unsigned, and y as signed, no ? I'm not familiar with LLVM debug info, >> but maybe I can find this info there ? > > probably it can be extracted from debug info, but what if there is no debug > info? Can you please explain what you intend to do with this information - > then maybe we can

On Sun, Jul 31, 2011 at 7:36 AM, Carlo Alberto Ferraris <cafxx at strayorange.com> wrote: > I'm trying to figure out how to feed a blockaddress to a switch condition > AND destination (basically emulating an indirectbr via a switch; I know it's > not a good approach, I'm just experimenting). > Suppose I have the following: > > SwitchInst *s =

Hi I write a LLVM function pass. The pass will loop the basicblock in the function, check the instruction's type with dyn_cast<switchinst>, print the instruction and the basicblock's successors. I think it is not very complex. My bitcode file is about 30M. My CPU is i7-7700(3.6GHz). It has been running for 60 hours but it is still running. I am not sure whether this is a normal

Hi all! I collected some statistics for SwitchInst, based on our test-suite. I found that efficiency is meaningful for parser-like applications only, about 15-20% of cases may be reduced (see top 10 items in Raw sheet of attached .xls file). Below some numbers. Total number of cases in all test-suite -- 11835. Clusters possible to make -- 503 Clusters with size (H - L) + 1

Hi, if I want to know how switch instructions are handled in the backend, where do I have to look first? I'm not familiar with the backend framework and I couldn't figure out the interface between the LLVM instruction 'SwitchInst' and whatever there is in the backend. I would be very happy about every hint where I have to look to find the entry point of switch instructions in the

Hi all, I am slowly working on a SwitchInst optimizer (http://llvm.org/PR8125) and now I am running into a deficiency of the x86 peephole optimizer (or jump-threader?). Here is what I get: andl $3, %edi je .LBB0_4 # BB#2: # %nz # in Loop: Header=BB0_1 Depth=1 cmpl $2, %edi

Hi, guys I am interesting about how to get the switch case value form the Machine Instruction. I know the switch will be converted to jump-table in the Machine Instruction. And in the phase CodeGen , the case-value of SwitchInst can get esasly. but it seems no case -value in Machine Instruction. The MI as follows: Frame Objects: fi#0: size=1, align=0, at location [SP] fi#1: size=4,

Some glitch in the emailer? I have received this message 3 times in a row!? I think that by the time it gets as far as MI-level there is no reversible method of determining the 'case' label at all. The reason I say this, is that I have often seen optimisations that coalesce groups of values into interesting logical tests and jump-tables are completely avoided. For example, a simple

Thanks for your help. Is there possible I can get the realily case value form the MI? For the case in https://bugs.llvm.org/show_bug.cgi?id=34902. as follows. ############################# * GCC v7.1 generated assembly ############################# ** Options: -Os -marm -march=armv7-a foo: @ args = 0, pretend = 0, frame = 0 @ frame_needed = 0, uses_anonymous_args = 0 sub

Hi I just had some code which filtered via isa<UnaryInstruction>. Strangely enough not only the instructions which inherited UnaryInstructions but also: GetElemPtrInst, SwitchInst , xor, shl where true on isa<UnaryInstruction>. While the first two seem to be at least semantically ok the latter seem somehow wrong? I didn't find the place where the isa_impl templates where

On Oct 6, 2010, at 6:16 PM, Gabor Greif wrote: > Hi all, > > I am slowly working on a SwitchInst optimizer (http://llvm.org/PR8125) > and now I am running into a deficiency of the x86 > peephole optimizer (or jump-threader?). Here is what I get: > > > andl $3, %edi > je .LBB0_4 > # BB#2: # %nz >

Hi all, I was trying to implement an obfuscation tool for C-code on the basis of LLVM. I got a prototype of the simple obfuscation transformation which converting control flow graph to something like a state machine. I am not sure I will have time to work on extending further this tool with new transformations like opaque predicates and decided to put here source code I have by now with hope

Hi, I am trying to prune some uninteresting llvm ir branches, corresponding to the *if-else* condition in the source code. And here is the procedures: 1. Get the BasicBlock containing the BranchInst which has 2 successors(in order to keep consistent with the source code I am using the llvm ir without any optimizations, so SelectInst/SwitchInst/PHINode is absent), one of which should be

Hi, I just thought of trying vmkit and checked out the source from the svn repo a few minutes back. The build is failing with the following error. llvm[4]: Compiling CGCleanup.cpp for Release+Asserts build CGCleanup.cpp:507:36: error: no member named 'getCaseSuccessor' in 'llvm::SwitchInst'; did you mean 'getSuccessor'?

Duncan Sands wrote: > Hi Nick, > >> I'm looking for input into the syntax for future metadata work. The plan >> is to make MDNodes hold a list of WeakVHs which will allow us to track >> metadata associated with values even through calls to >> ReplaceAllUsesWith. It also means that you can refer to other Values in >> the program, including instructions

Moving to LLVM dev to discuss the possibility of extending the cast infrastructure to handle this. On Tue, Nov 20, 2012 at 5:51 PM, John McCall <rjmccall at apple.com> wrote: > On Nov 18, 2012, at 5:05 PM, David Blaikie <dblaikie at gmail.com> wrote: >> TypeLoc casting looks bogus. >> >> TypeLoc derived types return true from classof when the dynamic type >>

This addition converts strlen() calls to strnlen() when the result is compared to a constant. For example, the following: strlen(s) < 5 Becomes: strnlen(s, 5) < 5 That way, we don't have to walk through the entire string. There is the added overhead of maintaining a counter when using strnlen(), but I thought I'd start with the general case. It may make sense to only use this