similar to: __builtin_thread_pointer for RISC-V

Hi, Sam. I think that it's a fair comparison. Keep in mind that the GP is only used to reach global variables of local scope and the GOT, where the address of global variables of global scope reside. This model assumes that the distance between the GP and the global data area, GOT and local scope variables is defined at link time. __ Evandro Menezes ◊ SiFive ◊ Austin, TX > On Mar

For background on these calls, see <http://lists.llvm.org/pipermail/llvm-dev/2019-September/135087.html>. Reminder: the purpose is to co-ordinate between active contributors. If you have support questions etc then it's best to post to llvm-dev. We have a call each Thursday at 4pm GMT, via <https://meet.google.com/ske-zcog-spp>. I've created a shared calendar which may help

For background on these calls, see <http://lists.llvm.org/pipermail/llvm-dev/2019-September/135087.html>. Reminder: the purpose is to co-ordinate between active contributors. If you have support questions etc then it's best to post to llvm-dev. We have a call every alternate Thursday at 4pm GMT, via <https://meet.google.com/ske-zcog-spp>. We have a shared calendar which may help

Oh, I wasn’t really thinking about devices without an MMU where the addresses are physically separated. Makes sense. This reminds me of rwpi on ARM; it has a sort of similar scheme of referring to data indirectly through a pointer, but it also changes the ABI to keep the pointer in a reserved register. -Eli From: Evandro Menezes <evandro.menezes at sifive.com> Sent: Friday, March 20, 2020

For background on these calls, see <http://lists.llvm.org/pipermail/llvm-dev/2019-September/135087.html>. Reminder: the purpose is to co-ordinate between active contributors. If you have support questions etc then it's best to post to llvm-dev. We have a call every alternate Thursday at 4pm BST, via <https://meet.google.com/ske-zcog-spp>. We have created a shared calendar which

Hi Everyone, I am wondering how to use RISC-V V (Vector) extension instructions in LLVM IR. In 2019 Kruppe and Espasa gave a talk [1] overviewing the Vector extension and on slide 16 [2] they show LLVM IR samples which use the vector instructions through intrinsic functions, such as: %vl = call i32 @llvm.riscv.vsetvl(i32 %n) At the time of the talk (April 2019) LLVM support for the V

Hi all developers, I'm changing compiler from gcc to llvm on a RISCV target now. but I found in some case the assembly code generated by llvm is much more than gcc. It cause my program's performance about 40% decrease. The flowing is a simple test code. It shows the problem. We can see than gcc prefer to use pointer to iterate the array, but llvm perfere to use index to iterate

If I’m following correctly, there are two size-limited areas. One area, limited to 2GB, is the “text” area. This contains all the code. Then there’s a “global” area, limited to 4GB, which is pointed to by the global pointer. This contains the GOT, plus a flexible area that the object file can stick small bits of data into. And then outside of both of those, additional data is unlimited. It

As you will have seen from previous postings, I've been working on upstream LLVM support for the RISC-V instruction set architecture. The initial RFC <http://lists.llvm.org/pipermail/llvm-dev/2016-August/103748.html> provides a good overview of my approach. Thanks to funding from a third party, I've recently been able to return to this effort as my main focus. Now feels like a good

Thanks. I have checked the hook DAGCombiner::isMulAddWithConstProfitable And I think the above condition is too aggressive. // If the add only has one use, this would be OK to do. if (AddNode.getNode()->hasOneUse()) return true; Shall we make it to if (AddNode.getNode()->hasOneUse() && TargetLowering.isCheaperCommuteAddMul(......)) return true; The virtual hook

On 18 August 2016 at 00:08, Renato Golin <renato.golin at linaro.org> wrote: > On 17 August 2016 at 10:14, Alex Bradbury via llvm-dev >> * Codegen >> * Compressed instruction set support (RVC) >> * Benchmarking and comparison to GCC RISC-V (and potentially other archs) > > What about buildbots? > > I'm assuming "check-all" would be enough for

On Wed, 22 Jan 2020 at 19:55, Chris Lattner via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > On Jan 21, 2020, at 5:00 AM, Alex Bradbury <asb at lowrisc.org> wrote: > >> This all makes sense to me. > > > > That's correct, thanks for the feedback. > > > > I do like the idea from James of having the compiler always spit out a > > note

On Tue, 21 Jan 2020 at 01:14, Chris Lattner <clattner at nondot.org> wrote: > > On Jan 16, 2020, at 10:01 AM, Alex Bradbury via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > I believe code should be committed to LLVM when it is of sufficient > > quality, when it can be shown to benefit the LLVM user or developer > > communities, and when there is someone

Hi all, I am proposing the integration of a backend targeting the RISC-V ISA. RISC-V is a free and open instruction set architecture that was originally developed at UC Berkeley. Future development of the ISA specification will be handled by the 501(c)(6) non-profit RISC-V Foundation and its members <https://riscv.org/membership/?action=viewlistings>. You can find much more information at

Yes - this has been in InstCombine for a long time: https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp#L268 We could say that the canonicalization should be reversed, but that probably uncovers more missing optimizations. The code size concern is legitimate. For example on x86, gcc asm is 2 bytes smaller on this example:

# Overview and background RISC-V is a free and open instruction set architecture. It is a modular specification, with a range of standard extensions (e.g. floating point, atomics, etc). New standard extensions are developed through RISC-V Foundation working groups. The specifications for such extensions (e.g. vector and bit manipulation) are publicly available, but are still in flux and won't

I built llvm + clang from source, a github clone from today: clang version 11.0.0 (https://github.com/llvm/llvm-project.git 91aa67bf290bc7f877b1b90128284863bc31aa43) I compiled a small program: #include <stdint.h> int main() { uint8_t a = 2; uint8_t b = 5; uint8_t c = a * b; } $ clang -c -target riscv32 -march=rv32imc -g main.c Works fine. The dumped assembly seems to not know

This approximately follows my understanding and expectation. I think that, if you have commit access, commits to improve release notes fall under the contribution guidelines for documentation and therefore do not require a full Phabricator review. I know Alex Bradbury tries to coordinate the RISC-V backend-related release notes based on the backend changes since the last release, and this seems

I'd like to convert the following call A at GDPLT //R_HEX_GD_PLT_B22_PCREL to call __tls_get_addr //R_HEX_B22_PCREL "A" is a TLS variable and preceding code has prepared for the call. When the R_HEX_GD_PLT_B22_PCREL is found it will initially point to the TLS variable so at that point I'd like to define a __tls_get_addr symbol and update the relocation's type and symbol

Something that would be good to get clarity on: The RISC-V backend recently had a bugfix patch that got backported to the 10.0.1 branch. The original patch introduced a new virtual method in TargetLowering.h, and the backported patch [1] was rewritten to avoid changing the ABI of libLLVM.so. This feels like some kind of policy decision about the C++ ABI beyond "it's entirely