similar to: _ExtInt, LLVM integers and constant time

Displaying 20 results from an estimated 800 matches similar to: "_ExtInt, LLVM integers and constant time"

2020 Apr 22
3
_ExtInt, LLVM integers and constant time
> On Apr 22, 2020, at 12:24 AM, Roman Lebedev via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > On Wed, Apr 22, 2020 at 9:35 AM Adrien Guinet via llvm-dev > <llvm-dev at lists.llvm.org <mailto:llvm-dev at lists.llvm.org>> wrote: >> >> Hello everyone, >> >> After reading the nice blog post about _ExtInt, I was wondering whether >>
2018 Jan 08
1
LLVM Social - Paris: January 30th, 2018
The next LLVM social in Paris will happen on January 30th, 2018. Everyone interested in LLVM, Clang, lldb, Polly, lld, ... is invited to join. Event details, including registration (free but mandatory) at http://www.meetup.com/LLVM-Clang-social For this meetup, Adrien Guinet, Serge Guelton and Juan Manuel Martinez will talk about the "Challenges when building an LLVM bitcode
2017 Jun 20
3
LoopVectorize fails to vectorize loops with induction variables with PtrToInt/IntToPtr conversions
On 06/20/2017 03:26 AM, Hal Finkel wrote: > Hi, Adrien, Hello Hal! Thanks for your answer! > Thanks for reporting this. I recommend that you file a bug report at > https://bugs.llvm.org/ Will do! > Whenever I see reports of missed optimization opportunities in the face > of ptrtoint/inttoptr, my first question is: why are these instructions > present in the first place? At
2018 Dec 16
2
LLC Version 3.8 : Unsupported library call operation for a mul instruction
Hello List, I am on the hook to instrument a piece of legacy LLVM IR code, and then we are planning to feed to the SeaHorn framework for some model checking tasks. After the instrumentation, I tried to use llc (version 3.9) to compile the IR code, and it works fine. However, when I try to use llc (version 3.8.1, the default llvm version of SeaHorn) to compile the IR code, it shows the following
2017 Jun 17
5
LoopVectorize fails to vectorize loops with induction variables with PtrToInt/IntToPtr conversions
Hello all, There is a missing vectorization opportunity issue with clang 4.0 with the file attached. Indeed, when compiled with -O2, the "op_distance" function get vectorized, but not the "op" one. For information, this test case has been reduced from a file generated by the Pythran compiler (https://github.com/serge-sans-paille/pythran). If we take a look at the generated
2013 Nov 18
1
[LLVMdev] Modular arithmetic processors
Thanks for your insightful suggestions. Yes, I am programming for a real device that does modular arithmetic (and only modular arithmetic). The modulus N is fixed during a single launch of a program. One way I could also come up with is to simply use add i256 %a, %b to represent a + b mod n, and let LLVM passes to reason about possible optimizations. However these are not semantically identical
2016 Apr 14
2
ABI for i256 in MCJIT
Hi, I have a small JIT project based on MCJIT. The generated LLVM IR code uses the i256 type. Also, the jitted code has to call back the host application from time to time. E.g. it calls a function i256 @callback(i256). 1. Can the callback function be implemented on the host application side (C/C++) to match the ABI used for the call by MCJIT? Or maybe the i256 has be to be casted to
2013 Nov 15
2
[LLVMdev] Modular arithmetic processors
I've been playing around with LLVM to write a backend for a rather "simple" (co-)processor. Assume that only three arithmetic instructions exist: ADD mod N, SUB mod N and MUL mod N. The modulus N is programmable and stored in a register. No ordinary arithmetic instructions are available. The word size is 256-bit. In other words, the following function, b + c mod N, corresponds to
2013 Nov 15
0
[LLVMdev] Modular arithmetic processors
Hi, My personal opinion: Just to be sure I understand what you're considering: you want to write a backend that will produce optimized machine code for a device with modular arithmetic instructions (not simulate such a device on a standard CPU)? In which case, won't the same assumptions that are embodied in the transformations for the case of unsigned 2's complement arithmetic (in
2012 Nov 14
2
[LLVMdev] Question about llvm.ctpop.*
Hi, Following is excerpted from http://llvm.org/releases/3.1/docs/LangRef.html#int_ctpop. How come the return type needs to be consistent with parameter type? i64/i128 seems to be overkill, and i8, i16 are inconvenient. ----------------------------------- declare i8 @llvm.ctpop.i8(i8 <src>) declare i16 @llvm.ctpop.i16(i16 <src>) declare i32 @llvm.ctpop.i32(i32
2010 May 26
2
[LLVMdev] i256 for x86_64
Hello all I have a very simple handwritten .ll file that can be translated to native assembly on x86_64 when I use i128. But if I use i256 I get an error. see the file and the first line of the error below. Any help is appreciated! I played a little bit with target datalayout but it didn't help. Best Ehsan Input File: target datalayout =
2010 May 26
0
[LLVMdev] i256 for x86_64
On May 25, 2010, at 5:16 PM, Ehsan Amiri wrote: > Hello all > > I have a very simple handwritten .ll file that can be translated to native assembly on x86_64 when I use i128. But if I use i256 I get an error. see the file and the first line of the error below. Any help is appreciated! I played a little bit with target datalayout but it didn't help. This works for me on mainline.
2020 May 18
2
Use Galois field New Instructions (GFNI) to combine affine instructions
On 5/18/20 8:24 PM, Craig Topper wrote: > I can tell you that your avx512 issue is that v64i8 gfni instructions also > require avx512bw to be enabled to make v64i8 a supported type. The C > intrinsics handling in the front end know this rule. But since you > generated your own intrinsics you bypassed that. Indeed that's the issue... I was stick with what Intel announces here
2008 Sep 08
2
[LLVMdev] Integer questions
On Sep 5, 2008, at 3:07 PM, Duncan Sands wrote: > The current maximum the code generators support is i256. If you try > to > use bigger integers it will work fine in the bitcode, but if you try > to do code generation the compiler will crash. FYI, there is one other issue here, PR2660. While codegen in general can handle types like i256, individual targets don't always have
2019 Nov 28
2
SLP example not being vectorized
Hi, I am new to llvm with a particular interested in the optimization area, specially on SLP. While working through the tutorial, I ran this example [1] with the hope to see SLP vectorization in action but for some reason, I do not see it on the LLVM assembly as seen below. Is there anything I am missing? I am using Clearlinux as build machine and this has clang version 9.0.0.
2020 Oct 08
4
__attribute__((apple_abi)): targeting Apple/ARM64 ABI from Linux (and others)
Hello everyone, I made a quick patch to clang/llvm to introduce an "apple_abi" function attribute (https://github.com/aguinet/llvm-project/commit/c4905ded3afb3182435df30e527955031cb0d098), to be able to compile functions for the Apple ARM64 ABI when targeting other ARM64 OSes (e.g. Linux). This can be seen as the Apple version of the already existing "ms_abi" attribute. In
2015 Oct 05
3
RFC: Pass for lowering "non-linear" arithmetics of illegal types
Hi LLVM, This is my idea I had some time ago, when I realized that LLVM did not support legalization of some arithmetic instructions like mul i256. I have implemented very simple and limited version of that in my project. Is it something LLVM users would appreciate? 1. The pass transforms IR and is meant to be run before CodeGen (after IR optimizations). 2. The pass replaces
2009 Nov 11
1
[LLVMdev] Proposal: intp type
On 10 Nov., 15:10, me22 <me22... at gmail.com> wrote: > 2009/11/9 Kenneth Uildriks <kenneth... at gmail.com>: > > > > > 1. Conversions to/from other integer types: right now, integer type > > conversions are always explicity specified as either a trunc, a sext, > > or a zext.  Since the size of intp is not known at IR generation time, > > you
2008 Sep 05
0
[LLVMdev] Integer questions
Hi, > First, I guess that smaller integer sizes, say, i1 (boolean) are > stuffed into a full word size for the cpu it is compiled on (so 8bits, > or 32 bits or whatever). on x86-32, an i1 gets placed in an 8 bit register. > What if someone made an i4 and compiled it on 32/64 bit > windows/nix/bsd on a standard x86 or x64 system, and they set the > value to 15 (the max size of
2008 Sep 08
0
[LLVMdev] Integer questions
On Mon, Sep 8, 2008 at 12:08 PM, Dan Gohman <gohman at apple.com> wrote: > FYI, there is one other issue here, PR2660. While codegen in > general can handle types like i256, individual targets don't always > have calling convention rules to cover them. For example, returning > an i128 on x86-32 or an i256 on x86-64 doesn't doesn't fit in the > registers designated