similar to: How to handle UMULO?

I think your users will be very upset if you don't set the boolean return value correctly :-) Whatever work it takes to determine the correct value for it, if the user code doesn't need/use that value then the dead code will be eliminated later. But if they need that return flag then they will want it to be correct! You may need to use a multiply instruction that returns a

If your target has a cheap count-leading-zeros instruction, you'd be able to determine whether an unsigned multiply will overflow or not, in most cases, without doing the long version of the multiplication. This is because an N-bit number times an M-bit number will produce a result that is either N+M bits wide or N+M-1 bits wide. If an N+M bit result will fit in your result type, you are

Also you might need to check use PostRASchedulerList or PostMachineScheduler, PostRASchedulerList is considered deprecated as mentioned in [1]. [1] http://lists.llvm.org/pipermail/llvm-dev/2017-April/112348.html HTH, chenwj 2017-06-10 4:03 GMT+08:00 陳韋任 <chenwj.cs97g at g2.nctu.edu.tw>: > Not saying I am totally understand how thing works, but I think you're > misleading >

Hi Justin, I believe the PTX section in the link below need some love, updating "lib/Target/PTX" to "lib/Target/NVPTX" for example. Would you like to take a look? http://llvm.org/docs/CodeGenerator.html#the-ptx-backend 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 all, I think it's Gentoo's bug, but I want to know if anyone has the same issue here. I am compiling LLVM trunk on Gentoo (gcc 4.5.2), and I get error message below, --- make[4]: Entering directory `/nfs_home/chenwj/llvm-3.1/svn/build/tools/clang/lib/Frontend' llvm[4]: Compiling InitHeaderSearch.cpp for Release+Asserts build

Hi 陳韋任, Sorry for the late response. On Apr 21, 2012, at 8:03 PM, 陳韋任 wrote: > I have a native compile and the result seems better... You can compare > the result of cross compile [1] and the native compile [2]. > > Any though? > I'm not particularly happy about the failures here. We need to get to the bottom of them. In the previous email, you tried setting CFLAGS and

Hi All, I have two trivial patches waiting for review. - https://reviews.llvm.org/D33281 - https://reviews.llvm.org/D32929 Anyone? :-) Regards, chenwj -- Wei-Ren Chen (陳韋任) Homepage: https://people.cs.nctu.edu.tw/~chenwj -------------- next part -------------- An HTML attachment was scrubbed... URL:

Hi, folks I am trying to build LLVM-GCC 4.2 on a Linux/PowerPC machine. Actually, the PowerPC is a PS3. The source was downloaded from http://llvm.org/releases/2.8/llvm-gcc-4.2-2.8.source.tgz Here is my system information and configuration options: ---------------------------------------------------------------------- $ uname -a Linux ps3 2.6.32-rc2-00995-g96ebbe6-dirty #2 SMP Fri Oct 2

Thanks for the info, Philip. I will update the LLVM Programmer’s Manual first. Regards, chenwj Wei-Ren Chen (陳韋任) Homepage: https://people.cs.nctu.edu.tw/~chenwj 2017-04-02 18:11 GMT+08:00 Philip Pfaffe <philip.pfaffe at gmail.com>: > Hi chenwj, > > http://llvm.org/doxygen/Statistic_8h_source.html is the correct one. The > other two are remnants from older doxygen deployments.

Hi weiren, Thanks for your suggestion! Yes, I am trying to do this "nested flattening". It seems that I need a post-dominator tree-based algorithm to flatten the nested loops from the innermost to the outermost, level by level. Is there any feature already existed in LLVM tools? Or similar? On Sun, Oct 22, 2017 at 2:31 AM, 陳韋任 <chenwj.cs97g at g2.nctu.edu.tw> wrote: > If

Hi Pawel, PTX already be replaced with NVPTX. However, PTX subdirectory still sit in lib/Target in 3.2 release. Do you think update the release tarball is a good idea? Also could you remove it from the trunk? Thanks. 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 Homepage:

Hi Mats, It's private backend. I will try describing what I am dealing with. struct S { unsigned int a : 8; unsigned int b : 8; unsigned int c : 8; unsigned int d : 8; unsigned int e; } We want to read S->b for example. The size of struct S is 64 bits, and seems LLVM treats it as i64. Below is the IR corresponding to S->b, IIRC. %0 = load

Hi All, The description of ScheduleDAGMILive [1] says: ScheduleDAGMILive is an implementation of ScheduleDAGInstrs that schedules machine instructions while updating LiveIntervals and tracking regpressure. Does the live interval and register pressure part of ScheduleDAGMILive mean the subclass of ScheduleDAGMILive is a pre-RA scheduler? I assume the post-RA scheduler no need to take

Hi all, While building/testing LLVM/Clang on ARM, I often have problems that are undocumented on the website. I would like to contribute my experience if possible so that others can benefit from it. If this is a good idea, I am wondering on what page I should write it down, [1] or [2]? Regards, chenwj [1] http://llvm.org/docs/GettingStarted.html [2] http://llvm.org/docs/FAQ.html -- Wei-Ren

On Mon, Nov 07, 2011 at 04:10:29PM +0100, Wim Vander Schelden wrote: > I'm having the same problem. Does anyone know what's causing this? > > Kind regards, > > Wim What's your profiling procedure? I can only guess llvm-prof does not recognize the profiling data. Regards, chenwj -- Wei-Ren Chen (陳韋任) Computer Systems Lab, Institute of Information Science, Academia

Hi All, If the target supports quad-register R0:R1:R2:R3 (Rn is 32-bit register), is it possible mapping quad-register to v4i32 so that the following example work? typedef int v4si __attribute__ ((vector_size (16))); void foo(v4si i) { v4si j = i; } I don't know how to write CallingConv.td to represent the concept of occupying quad-register R0:R1:R2:R3 once seeing

Hello, I have followed steps given in - https://stackoverflow.com/questions/29910051/integrating-llvm-passes/48142693#48142693 <https://stackoverflow.com/questions/29910051/integrating-llvm-passes/48142693#48142693>, to integrate my pass with pass manager and run it with clang. I am able to run my pass with opt - opt -mypass but when I try to run it with clang, I always get an error -

Hi All, I am going to clean up those doxygen links on LLVM Programmer’s Manual [1], some are lost and some are too old. However, I am confused on which doxygen link I should pick up. I see there are mutiple links exist on LLVM web site for LLVM classes. Take class Statistic as example, there are: - http://llvm.org/doxygen/Statistic_8h-source.html (the oldest one, I believe it's

Hi all, I have some troubles in writing XXInstFormat.td for my little backend. I don't know how should I start writing up this file. Is there any general rule? Thanks. 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 Homepage: http://people.cs.nctu.edu.tw/~chenwj

Hi All, When seeing the title "Prolog/Epilog Code Insertion", I'd expect something about XXXFrameLowering.cpp (particular about emitPrologue/emitEpilogue). But the document [1] is about unwind. Is it placed at the right place/section? Thanks. [1] http://llvm.org/docs/CodeGenerator.html#prolog-epilog-code-insertion Regards, chenwj -- Wei-Ren Chen (陳韋任) Homepage: