similar to: Expected constant simplification not happening

Hello Has there been any progress on this topic ? The 3.9 optimizer output is still the same as I just looked. https://llvm.org/bugs/show_bug.cgi?id=24448 Ciao Nat! Sanjay Patel schrieb: > [cc'ing Zia] > > We have this transform with -Os for some cases after: > http://reviews.llvm.org/rL244601 > http://reviews.llvm.org/D11363 > > but something in this example is

Hi I have some inline function C code, that llvm could be optimizing better. Since I am new to this, I wonder if someone could give me a few pointers, how to approach this in LLVM. Should I try to change the IR code -somehow- to get the code generator to generate better code, or should I rather go to the code generator and try to add an optimization pass ? Thanks for any feedback. Ciao

Hello. Mikhail, with the more recent version of the LoopVectorize.cpp code (retrieved at the beginning of July 2016) I ran the following piece of C code: void foo(long *A, long *B, long *C, long N) { for (long i = 0; i < N; ++i) { C[i] = A[i] + B[i]; } } The vectorized LLVM program I obtain contains 2 vector.body blocks - one named

From: Nikolay Ivanets <stenavin@gmail.com> Inspection code checks /etc/mdadm.conf to map MD device paths listed in mdadm.conf to MD device paths in the guestfs appliance. However on some operating systems (e.g. Ubuntu) mdadm.conf has alternative location: /etc/mdadm/mdadm.conf. This patch consider an alternative location of mdadm.conf as well. --- daemon/inspect_fs_unix_fstab.ml | 13

Hello all, I've been working for the last month or so on a comprehensive mitigation approach to variant #1 of Spectre. There are a bunch of reasons why this is desirable: - Critical software that is unlikely to be easily hand-mitigated (or where the performance tradeoff isn't worth it) will have a compelling option. - It gives us a baseline on performance for hand-mitigation. - Combined

Attached are my draft patches to add edge + mouse button to the actions It is useful because the edge bindings are too easily triggered, an edge + mouse button is good because it confirms the action. An additional side benefit is that the mouse wheel can be used for rotating the cube and for the switcher (it is an excellent alternative to alt-tab). I wanted to share the patches before cleaning

Am 03.03.2015 um 19:49 schrieb Philip Reames <listmail at philipreames.com>: Hi Philip first thanks for your response, > You'll need to prove a bit more information to get any useful response. Questions: > 1) What's you're use case? Are you using clang to compile C code? Are you manually generating LLVM IR? yes the "inline function C code" will be compiled

I was trying to build the Linux kernel with clang and observed a crash due to incorrect loop optimization: drivers/base/firmware_class.c extern struct builtin_fw __start_builtin_fw[]; extern struct builtin_fw __end_builtin_fw[]; static bool fw_get_builtin_firmware(struct firmware *fw, const char *name) { struct builtin_fw *b_fw; for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw;

Hi All, I’m currently working on a simple task which needs to transform loops into tail-recursive functions. I found the CodeExtractor class a handy helper to use, but later encountered a problem. Consider the following CU struct S { int a, b; }; int foo(struct S *s, unsigned n) {   struct S *next = s;   unsigned i;   for (i = 0; i < n; ++i) {     if (!s[i].a)      

----- Original Message ----- > From: "Chandler Carruth" <chandlerc at google.com> > To: "Hal Finkel" <hfinkel at anl.gov> > Cc: "Hyojin Sung" <hsung at us.ibm.com>, llvmdev at cs.uiuc.edu > Sent: Thursday, July 16, 2015 1:06:03 AM > Subject: Re: [LLVMdev] Improving loop vectorizer support for loops > with a volatile iteration

----- Original Message ----- > From: "Chandler Carruth" <chandlerc at google.com> > To: "Hyojin Sung" <hsung at us.ibm.com>, llvmdev at cs.uiuc.edu > Sent: Wednesday, July 15, 2015 7:34:54 PM > Subject: Re: [LLVMdev] Improving loop vectorizer support for loops > with a volatile iteration variable > On Wed, Jul 15, 2015 at 12:55 PM Hyojin Sung

Here are my patches to add edge + button functionality. I still feel that there is a problem with gconf, but I have just made it so that the edge button functionality works. I have included a patch for gconf to display AnyButton if it is set to 0. There is also a patch to make the edge size configurable because 1 pixel was too small and the mouse keeps slipping off when using it for the

Using LLVM ToT and Hal's helpful slide deck [1], I've been trying to use `llvm.assume` to communicate pointer alignment guarantees to vector load and store instructions. For example, in [2] %5 and %9 are guaranteed to be 32-byte aligned. However, if I run this IR through `opt -O3 -datalayout -S`, the vectorized loads and stores are still 1-byte aligned [3]. What's going wrong? Do I

Here is original C code: void topup(int a[], unsigned long i) { for (; i < 16; i++) { a[i] = 1; } } Here is the IR before the pass where I expect SCEV to return trip-count value ; Function Attrs: nofree norecurse nounwind uwtable writeonly define dso_local void @topup(i32* nocapture %a, i64 %i) local_unnamed_addr #0 { entry: %cmp3 = icmp ult i64 %i, 16 br i1

On Jul 15, 2012, at 9:20 AM, Borja Ferrer <borja.ferav at gmail.com> wrote: > Jakob, one more hint, I've placed some asserts around the code you added and noticed that the InlineSpiller::insertReload() function is not being called. > > 2012/7/14 Borja Ferrer <borja.ferav at gmail.com> > Hello Jakob, > > I'm still getting the error, I can give you any other

I noticed that fourinarow is one of the programs in which LLVM is much slower than GCC, so I decided to take a look and see why that is so. The program has many loops that look like this: #define ROWS 6 #define COLS 7 void init_board(char b[COLS][ROWS+1]) { int i,j; for (i=0;i<COLS;i++) for (j=0;j<ROWS;j++) b[i][j]='.';

The following C code : #include <stdio.h> #include <stdlib.h> int TESTE2( int parami , int paraml ,double paramd ) { int varx=0,vary; int nI =0; //varx= parami; if( parami > 0 ) { varx = parami; vary = varx + 1; } else { varx = vary + 1; vary = paraml; } varx = varx + parami + paraml; for( nI = 1 ; nI <= paraml; nI++) { varx =

Hi I have this program in which fooBuf can only take on NULL or the address of local_fooBuf, and fooBuf and local_fooBuf have scope of the foo function. Therefore there is no way for the fooPtr argument to alias with fooBuf. However, LLVM basicaa and globalsmodref-aa say the 2 pointers may alias. I am thinking whether i should implement a limited form of point-to alias on the fooBuf pointer in

On Wed, Sep 2, 2015 at 5:36 AM, James Molloy <james at jamesmolloy.co.uk> wrote: > Hi, > > Coremark really isn't a good enough test - have you run the LLVM test suite > with this patch, and what were the performance differences? For the test suite single source benches, the 235 tests improved performance, 2 regressed and 705 were unchanged. That seems very optimistic.

When I increased COLS to the point where the loop could no longer be unrolled, the selection dag code generator generated effectively the same code as the default X86 code generator. Lots of redundant imul/movl/addl sequences. It can't clean it up either. Only unrolling all nested loops permits it to be optimized away, regardless of code generator. Jeff Cohen wrote: > I noticed