search for: intrinsics

Hello. I come back to this thread. But I want to ask a slightly different question. Is there a way to have LLVM IR language intrinsics that are given at construction time a string that is written at assembly generation time as it is? (so, basically having placeholders of strings in LLVM that remain untouched until the end, including code generation time.) More exactly, I would like to give something LIKE this in a middle-...

> > Do you have plans to add other intrinsics? I'm curious as to why there > > is an llvm.sin intrinsic and an llvm.cos intrinsic, but no llvm.atan > > intrinsic. Why is there an llvm.pow intrinsic but no llvm.log > > intrinsic? > > Intrinsics get added on demand. Generally there has to be a good reason &gt...

...t; >> Hi all, >> >> I'm interested in the impact of representing code via intrinsic functions, in contrast to via an instruction, when it comes to performing dead instruction/code elimination. As a concrete example, lets consider the simple case of the llvm.*.with.overflow.* intrinsics. >> >> If I have some sequence (> 1) of llvm.*.with.overflow.* intrinsics, as in the form of: >> >> @global = global i32 0 >> >> define void @fun() { >> entry: >> %res1 = call {i32, i1} @llvm.*.with.overflow.i32(i32 %a, i32 %b) >> %sum1 =...

Hi, When I define an intrinsic function with memory write permission, my assumption is that we can either attach [IntrReadWriteArgMem] or [] to the intrinsic function. Based on the comment of the source code , "IntrReadWriteArgMem - This intrinsic reads and writes only from memory that one of its arguments points to, but may access an unspecified amount." "If no property is set,

Adam Nemet via llvm-dev <llvm-dev at lists.llvm.org> writes: > I spent some time chatting with Adam about this and have a better > understanding of his concerns here. It seems to me that if having > masking intrinsics is the long-term solution we want, we should do > that now (for add and sub) rather than building arbitrary matrix > layout info into intrinsics, since a mask has all the information > that we actually need. > > I think that sounds like a reasonable compromise. We already...

Hi, My pass scans call instructions for standard C library calls. For some libc functions, however, LLVM uses intrinsics instead. For example, I see that my memcpy calls are replaced by the llvm.memcpy.* intrinsics. This is not a problem because I can simply look for llvm.memcpy calls when scanning for memcpy calls. The problem arises when LLVM implicitly inserts llvm.memcpy intrinsics into my bitcode files when it...

On Tue, Nov 27, 2007 at 10:50:03AM -0700, Jon Sargeant wrote: > > > Do you have plans to add other intrinsics? I'm curious as to why there > > > is an llvm.sin intrinsic and an llvm.cos intrinsic, but no llvm.atan > > > intrinsic. Why is there an llvm.pow intrinsic but no llvm.log > > > intrinsic? > > > > Intrinsics get added on demand. Generally there has...

Hi, I tried creating variable argument intrinsics which are to be placeholders for some instructions which should not be executed by the backend. Kindly help me with the errors in my "migrate_begin" intrinsic creation //Additions made to Intrinsics.td file: def llvm_migrate_begin : LLVMType<iAny>; def int_migrate_begin : Intrins...

Hi all, We somewhat recently created/updated element-wise unordered-atomic versions of the memcpy, memmove, and memset memory intrinsics: Memcpy: https://reviews.llvm.org/rL305558 Memmove: https://reviews.llvm.org/rL307796 Memset: https://reviews.llvm.org/rL307854 These intrinsics are semantically similar to the regular versions. The main difference is that the underlying operation is performed entirely with unordered atomic loads...

From: Villmow, Micah Sent: Tuesday, November 06, 2012 1:37 PM To: 'llvm-dev at cs.uiuc.edu' Cc: Guo, Xiaoyi Subject: Bug in SelectionDAG visitTargetIntrinsic We ran into a problem where specifying IntrNoMem was causing our instruction selection to fail with target specific intrinsics. After looking into the code and ISel debug it looks like tablegen and SelectionDAG are using different criteria to generate code for intrinsic_w_chain vs intrinsic_wo_chain. In CodeGenDAGPatterns.cpp, tablegen decides based on whether IntrNoMem is set or not. However with SelectionDAG, whether to...

On Dec 23, 2014, at 10:28 AM, Chris Bieneman <beanz at apple.com> wrote: >>> It should be straight-forward to have something like LLVMInitializeX86Target/RegisterTargetMachine install the intrinsics into a registry. >> >> I tried doing that a few years ago. It’s not nearly as easy as it sounds because we’ve got hardcoded references to various target intrinsics scattered throughout the code. > > I was just writing to say exactly this. There are a number of ways we could work...

...ic functions are; I thought, > why are users (including llvm-gcc...) required to duplicate all this > information in order to use them? I mean in order to call > getOrInsertFunction to get declarations for them. That is an excellent question! :) In the bad old days, we used to allow intrinsics with slightly different types (e.g. http://llvm.org/PR1093). Because of this, we didn't know what type to create them as. Fortunately however, this misguided past is all behind us now, and there is no longer a reason to not have this facility. > So I wrote this patch, which allows all th...

<table cellspacing='0' cellpadding='0' border='0' ><tr><td style='font: inherit;'>Hi,<br>I tried creating intrinsics which are to be<br>placeholders for a set of instructions (actually a section of a basic block) to be executed elsewhere(for e.g. in HW).<br>These intrinsics are to take care of the data dependencies of the set of instructions being replaced by them.<br>In the process I created a...

Hi, I was looking at the x86 vector intrinsics for converting half precision floating point numbers and I'm a bit confused as to why certain types were chosen. I've gone ahead and used their current definition with success but I'd like to understand why the types used with these intrinsics are done this way. For reference see ``inc...

Do you have plans to add other intrinsics? I'm curious as to why there is an llvm.sin intrinsic and an llvm.cos intrinsic, but no llvm.atan intrinsic. Why is there an llvm.pow intrinsic but no llvm.log intrinsic? Also, have you thought about integer intrinsics like multiprecision multiply (u32xu32->u64) and multiprecision div...

...> > why are users (including llvm-gcc...) required to duplicate all this > > information in order to use them? I mean in order to call > > getOrInsertFunction to get declarations for them. > > That is an excellent question! :) In the bad old days, we used to allow > intrinsics with slightly different types (e.g. http://llvm.org/PR1093). > Because of this, we didn't know what type to create them as. > > Fortunately however, this misguided past is all behind us now, and there > is no longer a reason to not have this facility. It appears there is at leas...

Hi all, I'm interested in the impact of representing code via intrinsic functions, in contrast to via an instruction, when it comes to performing dead instruction/code elimination. As a concrete example, lets consider the simple case of the llvm.*.with.overflow.* intrinsics. If I have some sequence (> 1) of llvm.*.with.overflow.* intrinsics, as in the form of: @global = global i32 0 define void @fun() { entry: %res1 = call {i32, i1} @llvm.*.with.overflow.i32(i32 %a, i32 %b) %sum1 = extractvalue {i32, i1} %res, 0 %obit1 = extractvalue {i32, i1} %res, 1...

LLVM knows what all the types of the intrinsic functions are; I thought, why are users (including llvm-gcc...) required to duplicate all this information in order to use them? I mean in order to call getOrInsertFunction to get declarations for them. So I wrote this patch, which allows all this code to be generated automatically. Is this a good approach? Dan -- Dan Gohman, Cray Inc. <djg at

Hi everyone, According to the current design an intrinsic call that depends on current floating point environment (for example, rounding mode) or change it (for example by raising FP exceptions) is represented by constrained intrinsics. The latter have attached metadata that provide info about current FP environment and have attribute `IntrInaccessibleMemOnly` that helps keeping order of operations that access FP environment. Non-constrained intrinsics are considered as working solely in default FP environment. This approach has...

Hi, Thank You for the advice and we were able to solve that problem by the following modifications to the Instrinsics.td file. But I now have an "Invalid Intrinsic name" error This error occurs presumably because the created intrinsic is named: llvm.migrate_begin.i32 Intrinsics.gen checks for a string length of 18 (i.e. the length without the .i32). Kindly help me through it. //Additions made to Intrinsics.td file: def int_migrate_begin : Intrinsic<[llvm_i32_ty,llvm_vararg_ty], [IntrWriteMem],"llvm.migrate_begin">; //A section of the code which deal...