similar to: [LLVMdev] Why can't comparisons with negative zero be simplified?

Hi all, I seem to be unable to cast a vector of integers to a vector of floats (uitofp [4 x i8] to [4 x float], to be exact). It hits an assert in LegalizeDAG.cpp line 5433: "Unknown int value type". The Assembly Language Reference Manual's definition of uitofp doesn't indicate that this is unsupported, so it looks like a bug to me. I'm on an x86 system by the way. My

Since Clang does not seem to allow type casts, such as uchar4 to float4, between vector types, it seems it is necessary to write them as element by element conversions, such as typedef float float4 __attribute__((ext_vector_type(4))); typedef unsigned char uchar4 __attribute__((ext_vector_type(4))); float4 to_float4(uchar4 in) { float4 out = {in.x, in.y, in.z, in.w}; return out; } Running

Hello, As I understand, in LLVM IR it cannot be determined whether a register of type int is signed or unsigned. If one wants to convert an integer to a double, which instruction should be used:  "uitofp" or "sitofp" ? We track the values taken by all load instructions and we process them using a function. If the value is a pointer, we use int64 as the type of the function

Hi everyone, I'm learning how to use LLVM API and JIT engine and I've come across with an issue I haven't been able to figure out. The problem I'm having is that the wrong float is being stored in a float global variable. The code snippet I use to generate the float value is as follow: llvm::Type* type = // initialize with the global variable type; std::string

[+CC Andy] Hi Elena, I don't have any fundamental issues with teaching SCEV about floating point types, but given this will be a major change, I think a high level roadmap should be discussed on llvm-dev before we start reviewing and committing changes. Here are some issues that I think are worth discussing: - Core motivation: why do we even care about optimizing floating point

Hi all, Does PTX backend support llvm sitofp instruction? I failed to compile my llvm source when use llc -march=ptx32. The reason is that the source has a sitofp instruction. After i changed the instruction into uitofp manually, it passed. Thanks in advance, best, Yabin -------------- next part -------------- An HTML attachment was scrubbed... URL:

When the uitofp and sitofp instructions convert e.g. from i64 to float, what rounding mode do they use? Answers in the form a patch to LangRef.html would be great! Thanks, Jay.

On Thu, Nov 8, 2018 at 11:35 PM Fabian Giesen via llvm-dev < llvm-dev at lists.llvm.org> wrote: > What is so complicated about these? Shouldn't they just correspond to > two compares + selects? > > To give a concrete example, x86 MIN[SP][SD] and MAX[SP][SD], > respectively, correspond exactly to > > MIN*: select(a < b, a, b) (i.e. "a < b ? a : b")

Hi, I'm not sure what the expected behavior of calling a bitcasted function is. Suppose you have a case like this (which you get on the source level from attribute alias): @alias_f32 = alias bitcast (i32 (i32)* @func_i32 to float (float)*) define internal i32 @func_i32(i32 %v) noinline nounwind { entry: ret i32 %v } define void @bitcast_alias_scalar(float* noalias %source, float* noalias

On Sat, Jun 21, 2008 at 4:24 PM, Nicolas Capens <nicolas at capens.net> wrote: > I seem to be unable to cast a vector of integers to a vector of floats > (uitofp [4 x i8] to [4 x float], to be exact). It hits an assert in > LegalizeDAG.cpp line 5433: "Unknown int value type". The Assembly Language > Reference Manual's definition of uitofp doesn't indicate that

The fptrunc instruction states "If the value cannot fit within the destination type, ty2, then the results are undefined." This is fine, but what about other floating-point operations that can overflow? For example, does 'mul double 1.0e300, 1.0e300' produce +infinity or is it undefined? I think LLVM should treat floating-point overflows consistently. On a similar note,

On 02/13/2014 11:35 AM, Tim Northover wrote: > Hi Reed, > >> but then many tests fail when i do a "make check" > > That's not normal (all tests pass for me on Linux and OS X). Is this > on your build machine, or a MIPS board with some odd > cross-compilation? The latter is more likely to have weird CMake > issues (I know AArch64 does if you're not

On Wed, Jul 24, 2013 at 4:03 AM, Jay Foad <jay.foad at gmail.com> wrote: > When the uitofp and sitofp instructions convert e.g. from i64 to > float, what rounding mode do they use? Answers in the form a patch to > LangRef.html would be great! The default rounding mode, just like every other floating-point operation. -Eli

> Does PTX backend support llvm sitofp instruction? Seems it doesn't support sitofp, search "Conversion to f32" in PTXInstrInfo.td. Regards, chenwj -- Wei-Ren Chen (陳韋任) Computer Systems Lab, Institute of Information Science, Academia Sinica, Taiwan (R.O.C.) Tel:886-2-2788-3799 #1667

Hi LLVMdev, In the specification of llvm ir, the select operation can takes a condition of vector type, 'select' Instruction Syntax: <result> = select *selty* <cond>, <ty> <val1>, <ty> <val2> *; yields ty* *selty* is either i1 or {<N x i1>} Overview: The 'select' instruction is used to choose one value based on a condition,

Hi, The following arbitrary example makes the code generators to get stuck (llvmc won't return from command line, Jit won't return from function call) Basically it is a CFG with circles, (the function will return by comparing a branch counter to a threshold on runtime - see the "Brancher" blocks below) Any idea what goes wrong? Is it a bug in llvm ? ; ModuleID =

Here is a patch containing all but one of the changes. I realized that the remainder/modulo discussion does indeed belongs to the srem instruction. The semantics of urem are obvious and need no further clarification. Best Regards, Jon 1572,1573c1572,1575 < notation (see below). Floating point constants must have a <a < href="#t_floating">floating point</a>

Hi, Lately we have come to realize how undef makes our life complicated.. Therefore in this email we propose to change the behavior of a few instruction to yield poison instead of undef in error cases. This follows the suggestion of Eli in https://reviews.llvm.org/D33654. Why is undef so bad? - I believe it's not possible to make newgvn correct with undef. See for example the discussion

Ulrich offered to do it instead since I expect he can get it done much faster than me. Instead I'm doing SIToFP and UIToFP. Ulrich said he wasn't going to be able to get to it for a couple of weeks, but that was a week or two ago. Ulrich? -----Original Message----- From: Cameron McInally <cameron.mcinally at nyu.edu> Sent: Tuesday, October 01, 2019 10:21 AM To: Kristof Beyls

On Mon, 31 Mar 2008, Jon Sargeant wrote: > The fptrunc instruction states "If the value cannot fit within the > destination type, ty2, then the results are undefined." This is fine, but > what about other floating-point operations that can overflow? For example, > does 'mul double 1.0e300, 1.0e300' produce +infinity or is it undefined? It is defined by IEEE to