similar to: Various Intermediate Representations. IR

On Tue, 14 Apr 2020 at 21:24, Michael Kruse <llvmdev at meinersbur.de> wrote: > > Currently, LLVM often uses the *i8 type (pointer to char) to represent > a pointer to some not-specified type. We are also working on replacing > the pointer-to-type pointer types by a single pointer type without a > specific pointee-type. Look for "opaque pointer" on llvm-dev and the

On Wed, 15 Apr 2020 at 17:28, David Blaikie <dblaikie at gmail.com> wrote: > > opaque pointers don't exist in the IR yet - the goal is to reduce the places that use non-opacity of pointer types already/today and then opacify the existing pointer type, rather than introducing an opaque pointer type & having it concurrently with non-opaque pointer types. (though in retrospect

On Sun, Apr 16, 2017 at 2:34 AM James Courtier-Dutton via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Hi, > > Did this work ever get done? There was a long thread about it back in 2015. > > I wish to use IRBuilder. > Is there any documentation? > How do I use the singular pointer type in GEP, LOAD, STORE instructions? > Sorry, no, the work is not complete - for

The attached patch includes no test-case and isn't consistent with the rest of the file: - constants should be on the right hand side of comparisons - the braces around your single line 'if' aren't needed. On Sun, Sep 15, 2013 at 2:39 PM, James Courtier-Dutton < james.dutton at gmail.com> wrote: > I attach a patch that fixes this bug. Applies to llvm 3.4svn > >

Hi, I am looking at the "LLVMOpInfoCallback GetOpInfo" callback. Example 1 GOOD: 41 c6 84 24 16 04 00 00 0c : movb $12, 1046(%r12) Makes calls to the callback with: Offset = 0x4, Size = 0x4 <- Octets: 16 04 00 00 Offset = 0x8, Size = 0x1 <- Octets: 0c That was correct. Example 2 BAD: c7 45 98 a1 ff ff ff : movl $4294967201, -104(%rbp) Makes calls to the callback

Test case attached. It is not a test case that works within the llvm test-suite yet, but it does demonstrate the problem. I would like some advice on how to modify this test_case so that it can be added to the automated llvm test cases. On 15 September 2013 23:02, David Majnemer <david.majnemer at gmail.com> wrote: > The attached patch includes no test-case and isn't consistent

I attach a patch that fixes this bug. Applies to llvm 3.4svn Please commit it please. Kind Regards James On 13 September 2013 17:46, James Courtier-Dutton <james.dutton at gmail.com>wrote: > Hi, > > I am looking at the "LLVMOpInfoCallback GetOpInfo" callback. > > Example 1 GOOD: > 41 c6 84 24 16 04 00 00 0c : movb $12, 1046(%r12) > > Makes

On Mon, 6 May 2019 at 10:13, James Courtier-Dutton via llvm-dev <llvm-dev at lists.llvm.org> wrote: > Although the above is mentioning bytes, looking at the "/ 8" and "& 0x7" makes it look like the author meant octets and not bytes. > Bytes can be any size of bits. I don't think you'll have much luck trying to make that stick for a general audience,

On 12 March 2013 16:39, Óscar Fuentes <ofv at wanadoo.es> wrote: > > This is not possible, except for specific cases. > > Consider this code: > > long foo(long *p) { > ++p; > return *p; > } > > The X86 machine code would do something like > > add %eax, 4 > > for `++p', but for x86_64 it would be > > add %rax, 8 > > But you

Hi, I am looking to decompile x86 ASM to LLVM IR. The original C is this: int test61 ( unsigned value ) { int ret; if (value < 1) ret = 0x40; else ret = 0x61; return ret; } It compiles with GCC -O2 to (rather cleverly removing any branches): 0000000000000000 <test61>: 0: 83 ff 01 cmp $0x1,%edi 3:

Hi, I know their are various tools that can take LLVM IR Bitcode and JIT it and execute it. Is there anything that can do the equivalent but at the LL\VM IR Bitcode level? So, that for example, I could set some initial conditions, and then single step through the IR Bitcode function, and pause it and print out any of the SSA values that I wish? Kind Regards James

Hi, I think this is a very simple question, and it must just be missing something. I am looking for find out how to assign a constant integer value to the variable in llvm ir. The following returns 12, and %var2 = 12. ; ModuleID = 't.c' target datalayout =

On Mar 15, 2013 10:53 PM, "Óscar Fuentes" <ofv at wanadoo.es> wrote: > > James Courtier-Dutton <james.dutton at gmail.com> writes: > > > I think this is a very simple question, and it must just be missing something. > > > > I am looking for find out how to assign a constant integer value to > > the variable in llvm ir. > > > > The

On Thu, Jun 19, 2014 at 5:56 PM, Duncan P. N. Exon Smith < dexonsmith at apple.com> wrote: > > > On 2014-Jun-18, at 21:14, Andrew Trick <atrick at apple.com> wrote: > > > > Is there any way we have this utility and just not claim that it is for > use with a numerics package? The only claim we’re making is that it is a > useful utility for writing compiler

On 7 May 2012 16:31, John Criswell <criswell at illinois.edu> wrote: > On 5/7/12 5:47 AM, James Courtier-Dutton wrote: >> >> Hi, >> >> I am writing a decompiler. I was wondering if some of LLVM could be >> used for a decompiler. >> There are several stages in the decompiler process. >> 1) Take binary and create a higher level representation of it.

Hi, I know most compilers go from AST to CFG. I am writing a decompiler, so I was wondering if anyone knew of any documents describing how best to get from CFG to AST. The decompiler project is open source. https://github.com/jcdutton/libbeauty The decompiler already contains a disassembler and a virtual machine resulting in an annotated CFG. It uses information gained from using a virtual

On Mon, 2019-05-06 at 15:56 -0700, Philip Reames via llvm-dev wrote: > > > On 5/6/19 2:43 AM, Tim Northover via llvm-dev wrote: > > On Mon, 6 May 2019 at 10:13, James Courtier-Dutton via llvm-dev > > <llvm-dev at lists.llvm.org> wrote: > > > Although the above is mentioning bytes, looking at the "/ > > > 8" and "& 0x7" makes

James Courtier-Dutton <james.dutton at gmail.com> writes: > I am looking to decompile x86 ASM to LLVM IR. > The original C is this: > int test61 ( unsigned value ) { > int ret; > if (value < 1) > ret = 0x40; > else > ret = 0x61; > return ret; > } > > It compiles with GCC -O2 to (rather

Hi, I have the x86 SBB instruction. how should I represent this in LLVM IR. (as part of a decompiler from binary to LLVM IR) Pre-conditions: %eax = 0xffffffff %edx = 0xffffffff %carry = 1 SBB %eax, %edx // %edx is the destination doing %edx = %edx - (%eax + carry) JC jump_destination1 // If the Carry flag is set, jump to jump_destination1 How do I represent this correctly in LLVM

On Mon, Oct 28, 2013 at 10:09 AM, James Courtier-Dutton <james.dutton at gmail.com> wrote: > My guess is that this is a missed optimization, but in real life, all > projects i have worked fix this in the C or C++ code using macros that > change what instructions are used based on target platform and its > endedness. One reason for writing code like this, i.e. explicitly spelling