similar to: [LLVMdev] Getting the trip count of a loop

Prakash Prabhu wrote: > I am trying to add a new loop pass in which I making a call to get the > trip count of the loop using > > Value *TripCountValue = L->getTripCount() That should work. Could you file a bug and attach the bytecode after 'opt -indvars -loop-rotate'? I would need that to determine why LoopInfo::getTripCount isn't returning any value. Nick

Thanks a lot for your guys' help!!! I guess once I am able to get *V* (which probably is a pointer to a Value object), then, I can instrument some code at the IR level to dump V. As long as I maintain V at this pass stage, I should be able to dump the loop trip count. This is true, isn't it? Basically, what I am going to do is to add a function call before the loop body, such as:

Hello, I'm writing a new function pass, and I'm having trouble with getTripCount() in Loop. If I generate the bitcode for the test code with no optimization then getTripCount() returns NULL, but if I pass - O3 to the front-end then getTripCount() returns fine. My phase calls addRequiredID(LoopSimplifyID) from getAnalysisUsage() and I also tried putting -mem2reg at the front

Sorry, I could not the the loop trip count with getTripCount(). I used a simple program as a test case: ------------------------------------------------------ #include <stdio.h> int getV(int i) { return i * 2; } int main() { int num = 10; int sum=0; int i; for (i=0; i<num; i++) { sum += getV(i); } return 0;

Hi, For me, getTripCount always returns null, even for trivial loops such as: void simple(int j) { for (int i = 0; i < 10; i++) { j++; } } Looking through the mailing list archive, it appears that getTripCount requires certain optimization passes to run first, but it's not clear which ones. There doesn't seem to be any documentation on this. Does anybody

Hi, Seems pass scalar-evolution+indvars fail to get the loop trip count of the following case: int foo(int x, int y, int lam[256], int alp[256]) { int i; int z = y; for (i = 255; i >= 0; i--) { z += x; lam[i] = alp[i]; } return z; } The final optimized ll code is : define i32 @foo(i32 %x, i32 %y, i32* %lam, i32* %alp) nounwind { entry: br label %bb bb:

Hi, I am trying to modify a loop by reducing the loop trip count from N to N-1 where N may be constant. I looked into using getTripCount[1] but discovered that this method returns a Value* which is N itself. This prevents me from using this method for changing the loop. I suggest creating another method for returning the 'cmp' instruction. The new getTripCount implementation will use the

hi, On Fri, May 7, 2010 at 8:59 AM, Trevor Harmon <Trevor.W.Harmon at nasa.gov>wrote: > Hi, > > For me, getTripCount always returns null, even for trivial loops such > as: > > void simple(int j) { > for (int i = 0; i < 10; i++) { > j++; > } > } > > Looking through the mailing list archive, it appears that getTripCount > requires

Hi Dan, Thanks for the reply. I got the labels for each outgoing edge (at the source node's 'structure' field) working. Is there a way to find out the outgoing edge number from EdgeIter. (Basically the Node in my graph has a a bunch of outgoing edges, so that I can just index into that collection within the node to get the appropriate edges' attributes). regards, Prakash On Tue,

Hi Evan, Thanks for the pointers. We found a simple test case that causes the problem (thanks to Tom in my group): #include<stdio.h> #include<stdlib.h> void test(); void (*funcPtr)(); int main(int argc, char **argv) { funcPtr = test; test(); } void test() { if(funcPtr == test) { printf("OK!\n"); } else { fprintf(stderr, "Bad!\n"); exit(1);

I found out that Loop::getTripCount method is obsolete in LLVM 3.1 Is there an alternative? -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20120702/ea6ca4e6/attachment.html>

Hi Eli, Thanks for the reply. I tried with -Xlinker="-ldl ". However it does not seem to make a difference. It seems that when bugpoint is run with --run-jit, the linker args are not passed to gcc (from tools/bugpoint/ExecutionDriver.cpp) : if (InterpreterSel == RunLLC || InterpreterSel == RunCBE || InterpreterSel == CBE_bug || InterpreterSel == LLC_Safe) RetVal =

Hi, Is there a way, from within an opt pass, to find the correspondence between an LLVM IR object and C source code (basically line number info similar to the one used with gcc + gdb to help debugging ), assuming either a llvm-gcc front end ? Sorry if this question was asked before. Thanks for your time. - Prakash

Hi all, I have two questions related to .dot graph output. Basically, I have a graph representing a program dependence graph like structure with (a) multiple edges between the same pair of nodes (b) each edge having a special (different) text/label I implemented a template-specialized version of DotGraphTraits for the my graph structure which given a node, uses a map_iterator (similar to the one

Hi Prakash, I don't know of an easy way to do this, other than to use random-access iterators so you can compute the distance between the edge and the beginning of the list of edges. Dan On Sep 16, 2008, at 2:58 PM, Prakash Prabhu wrote: > Hi Dan, > > Thanks for the reply. I got the labels for each outgoing edge (at the > source node's 'structure' field) working. Is

Hi all, I too am getting this error for x86_64 when I am trying to use the Data Structure Analysis ...I svn upped both the llvm main branch and the poolalloc today in the morning and recompiled everything from scratch : $ opt -load /home/pprabhu/llvm/llvm-install-x86-64/lib/libpoolalloc.so -ds-aa < o.bc opt: /home/pprabhu/llvm/llvm/lib/VMCore/PassManager.cpp:1418: virtual void

Hi all, Would it be correct to say that the only instructions in LLVM IR that modify/access memory potentially are the following: (1) LoadInst : Ref (2) StoreInst : Mod (3) VAArgInst : Ref (?) (4) AllocaInst : Mod (5) MallocInst : Mod (6) FreeInst : Mod (7) CallInst : Mod/Ref ? Also, my earlier impression was that the GEP instruction only computes the effective address and does not

Hi, I have a program that runs when statically compiled using llc and gcc but crashes with a segmentation fault when run with lli. I am trying to debug it with bugpoint and the initial part of bugpoint seems to be suggesting that I am somehow missing the linking with the libraries having dlsym/dlopen although I am passing it to lli : *$ bugpoint -run-jit

Hello, I'm having some trouble with getTripCount() ... again. In particular it fails in the first of the following two examples, although it works for the second. By fails, I mean it returns NULL. ---------- example 1 ---------- test1(int *a, const int *ip) { int k; for (k = 0; k < ip[2]; ++k) { a[k] = (k+11)/(k+2); } } ---------- example 2 ---------- test2(int

On May 6, 2010, at 6:32 PM, ether zhhb wrote: > As the comment said: > /// The IndVarSimplify pass transforms loops to have a form that > this > /// function easily understands. > > you could try -indvars. After adding -indvars to the opt command, getTripCount still returns null. I suppose it's possible, depending on the scheduling of the pass manager, that