similar to: [LLVMdev] experimenting with partial evaluation

Good evening, Pierre. Here is an example to you. attached. run with -disable-lazy-comilation. It is *as-is* for Win32 but might be applicable to *-linux-elf more smartly. It does get llvm::Function* by function ptr(not name!), and clone a specialized function, and execute specialized one in the same context as parent lli. > - In a running program, can I get pointers to the llvm Module that

Hi, I have a program as: int main(int argc, char **argv) { int a,b,k,l; scanf("%d%d",&a,&b); if (argc > 1) { k=a+b; } else { k=5; } l=a+b; printf("%d,%d",k,l); return 0; } Now i run the following on it: llvm-gcc -O1 -emit-llvm -c -o 1.bc 1.c llvm-dis 1.bc -o 1.ll opt

I am testing vectorization on the following test case: float x[1024], y[1024]; void myloop1() { for (long int k = 0; k < 512; k++) { x[2*k] = x[2*k]+y[k]; } } Vectorization failed due to "unsafe dependent memory operation". I traced the LoopAccessAnalysis.cpp and found the reason is the NoWrapFlag for SCEVAddRecExpr is not set and consequently the

[+Arnold] > On Jun 10, 2015, at 1:29 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: > > [+CC Andy] > >> Can anyone familiar with ScalarRevolution tell me whether this is an >> expected behavior or a bug? > > Assuming you're talking about 2*k, this is a bug. ScalarEvolution > should be able to prove that {0,+,4} is <nsw> and

Ok, so I think I've mis-represented what's really happening. Ignore my previous statements concerning %add :) Again, given: 05: for.body: ; preds = %entry, %for.body 06: %j.04 = phi i32 [ 0, %entry ], [ %inc, %for.body ] 07: %result.03 = phi i32 [ 0, %entry ], [ %add, %for.body ] 08: %conv2 = and i32 %result.03, 255 09: %add = add nsw

On Thu, Dec 20, 2012 at 8:36 AM, Matthew Curtis <mcurtis at codeaurora.org> wrote: > Ok, so I think I've mis-represented what's really happening. > Ignore my previous statements concerning %add :) > > Again, given: > > 05: for.body: ; preds = %entry, > %for.body > 06: %j.04 = phi i32 [ 0, %entry ], [ %inc, %for.body

Hi Sanjoy, >> I'm a bit apprehensive of adding more caching to solve problems created by caching; but if there is no way out of adding another cache, how about adding a cache that maps SCEV expressions to their simplified versions? Then we could do something like: I may be wrong but I think caching is not an issue in itself, but caching in the presence of self-recursion is. >>

Perfect, thank you very much :) 2011/10/26 Tobias Grosser <tobias at grosser.es>: > On 10/24/2011 11:32 PM, Marcello Maggioni wrote: >> >> Strange , with --enable-shared (I use auto tool by the way ...) it gives: >> >> MacBook-Pro-di-Marcello:examples Kariddi$ ./compile_ex.sh >> not_so_simple_loop >> clang (LLVM option parsing): Unknown command line

Hi Sanjoy, Thanks for investigating the issue! I am more interested in getting the underlying problem fixed rather than making this particular test case work. I think I have more test cases where this problem crops up. I would any day prefer consistent results over compile time savings which can lead to inconsistencies. These inconsistencies require significant developer time to analyze and fix

This sounds fine to me (and sorry for the delay!). -- Sanjoy On Mon, Mar 12, 2018 at 1:09 PM, Chawla, Pankaj <pankaj.chawla at intel.com> wrote: > Hi Sanjoy, > > So what is the verdict on this issue? > > Thanks, > Pankaj > > > -----Original Message----- > From: Chawla, Pankaj > Sent: Monday, February 26, 2018 11:12 AM > To: Sanjoy Das <sanjoy at

Mmm, this code seems to kill polly: #include <stdio.h> #include <stdlib.h> int main() { char *B; int i,j,k,h; const int x = 0, y=0; B = (char *)malloc(sizeof(char)*1024*1024); for (i = 1; i < 1024; i++) for (j = 1; j < 1024; j++) { if (i+j > 1000) B[j] = i; } printf("Random Value: %d", B[rand() % 1024*1024]); return 0; } running: opt

Hi Pankaj, On Sun, Feb 11, 2018 at 2:32 PM, Chawla, Pankaj <pankaj.chawla at intel.com> wrote: > Thanks for investigating the issue! > > I am more interested in getting the underlying problem fixed rather than making this particular test case work. I think I have more test cases where this problem crops up. I would any day prefer consistent results over compile time savings which

Hi Sanjoy, So what is the verdict on this issue? Thanks, Pankaj -----Original Message----- From: Chawla, Pankaj Sent: Monday, February 26, 2018 11:12 AM To: Sanjoy Das <sanjoy at playingwithpointers.com> Cc: Maxim Kazantsev <max.kazantsev at azul.com>; Serguei Katkov <serguei.katkov at azul.com>; llvm-dev at lists.llvm.org Subject: RE: [SCEV] Inconsistent SCEV formation for

Note that there is a slight difficulty due to the fact that we "sink" the trunc: (zext i16 {0,+,1}<%bb> to i32) + (65536 * ({0,+,1}<nuw><%bb> /u 65536) Here the recurrence lost it's <nuw> and got reduced to a i16 (on the left), but not on the right. But we can prove: - that (zext i16 {0,+,1}<%bb> to i32) has the same 16 LSB than (i32

Hi, +CC Max, Serguei This looks like a textbook case of why caching is hard. We first call getZeroExtendExpr on %dec, and this call does end up returning an add rec. However, in the process of simplifying the zext, it also calls into isLoopBackedgeGuardedByCond which in turn calls getZeroExtendExpr(%dec) again. However, this second (recursive) time, we don't simplify the zext and cache a

Hi Sanjoy, SCEV is behaving inconsistently when forming SCEV for this zext instruction in the attached test case- %conv5 = zext i32 %dec to i64 If we request a SCEV for the instruction, it returns- (zext i32 {{-1,+,1}<nw><%for.body>,+,-1}<nw><%for.body7> to i64) This can be seen by invoking- $ opt -analyze -scalar-evolution inconsistent-scev-zext.ll But when computing

Hi, I have problems to estimate the loop exit count of a simple loop with the ScalarEvolution class. simple loop: ...... int a = 0; for(int i; i < 10; ++i){ a = a + 1; }; ...... For the loop analyzation I use the ScalarEvolution class with the following initialization: ...... void analysis(Function* func) DominatorTree DT = DominatorTree(); DT.recalculate(*func);

On Jul 29, 2013, at 4:08 PM, Guo, Xiaoyi <Xiaoyi.Guo at amd.com> wrote: > Hi, > > We have a benchmark where there are 128 MAD computations in a loop. (See the attached IR.) Creating SCEVs for these expressions takes a long time, making the compile time too long. E.g., running opt with the “indvars” pass only takes 45 seconds. > > It seems that the majority of the time is

Hi Sanjoy, Thanks for the reply! Would it be possible for you to implement this? You know the codebase better than I do. Thanks, Pankaj -----Original Message----- From: Sanjoy Das [mailto:sanjoy at playingwithpointers.com] Sent: Tuesday, March 13, 2018 1:34 PM To: Chawla, Pankaj <pankaj.chawla at intel.com> Cc: Maxim Kazantsev <max.kazantsev at azul.com>; Serguei Katkov

Hi Andy, Thanks very much for looking into the problem. In this particular test case, it seems most of the time is spent in the sorting, not the grouping. Later, I realized that it seems in this test case most of the expressions to be compared have different length. I tried the following change in compare() when the LHS and RHS's types are the same: