similar to: [LLVMdev] alias analysis on llvm internal globals

I have the following function for which I need to find the root of a: f <- function(R,a,c,q) sum((1 - (1-R)^a)^(1/a)) - c * q To give context for the problem, this is a psychometric issue where R is a vector denoting the percentage of students scoring correct on test item i in class j, c is the proportion correct on the test by student k, and q is the number of items on the test in total. I

Hello, I have a question regarding PGO instrumented BBs (I use IR-level instrumentation). It seems that instrumented BBs do not match between the two compilations for profile-gen and profile-use for some cases. Here is an example from SPECcpu 2006 lbm (a simple case consisting of just two modules). In the first compilation, we have 5 instrumentation points for the main function as follows: $

Hi, Seems that on RWin 1.7.0 and 1.6.2 isSeekable returns F on binary files, while seek() works as expected on the same connection - see example below: > con = file(nm, "rb") > isSeekable(con) [1] FALSE > readBin(con, double(), 10) [1] 7.263824e-317 5.968155e-317 2.340685e-317 2.734062e-312 4.088386e-312 4.670335e-317 [7] 6.097545e-317 3.396341e-312 6.615484e-317

While building a package, I see the following: * checking R code for possible problems ... NOTE cheat.fit: no visible binding for global variable 'Zobs' plot.jml: no visible binding for global variable 'Var1' I see the issue has come up before, but I'm having a hard time discerning how solutions applied elsewhere would apply here. The entire code for both functions is below,

Hi! During my backend development I get the error message for some tests: *** Bad machine code: Virtual register def doesn't dominate all uses. *** (C source-code, byte-code disassembly and printed machine code at the end of the email) The first USE of vreg4 in BB#1 has no previous DEF in BB#0 or #1. But why? I can't see how the LLVM byte-code is transformed to the lower machine code.

Hi Quentin, yes, this happens quite late. With the Option --debug-pass=Structure it's in or after "Assembly Printer". I do have a very simple DAGToDAGISel::Select() method: SDNode *MyTargetDAGToDAGISel::Select(SDNode *N) { SDLoc dl(N); // default implementation if (N -> isMachineOpcode()) { N -> setNodeId(-1); return NULL; // Already selected. } SDNode

Hi Quentin, I added some debug output (N->dump()) in ::Select(SDNode*N) and compared it to the dot/Graphviz output (-view-legalize-types-dags; the last one with correct code). I found out, that some SDNodes are not passed to the ::Select(SDNode*N), approximately 11 nodes are missing. The first add-node (v1+v2) is missing. Is it normal that not all nodes are passes to ::Select()? Thanks,

Dear Daniel Berlin, I just tried MemorySSA analysis and get the next IR. However, I feel confused by the result. Specifically, why instruction *%3* relates to a *MemoryDef*. According to my understanding, I think *%3* should be related to a *MemoryUse*, right? ; Function Attrs: uwtable define void @_Z2f1v() #3 personality i32 (...)* @__gxx_personality_v0 { entry: ; 1 = MemoryDef(liveOnEntry)

Hi Quentin, Am 01.11.2014 um 00:39 schrieb Quentin Colombet <qcolombet at apple.com>: > > On Oct 31, 2014, at 11:00 AM, Boris Boesler <baembel at gmx.de> wrote: > >> Hi Quentin, >> >> I added some debug output (N->dump()) in ::Select(SDNode*N) and compared it to the dot/Graphviz output (-view-legalize-types-dags; the last one with correct code). I

Let me try to help. On Thu, Feb 8, 2018 at 12:13 PM, Qiuping Yi via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Thanks for your explanation. > > Do you mean that LLVM will not maintain the def-use chain for atomic > variables? > It is not a variable at the LLVM level. At the source level, it is a variable. At the LLVM IR level, it is lowered into memory operations. All

Thanks for your explanation. Do you mean that LLVM will not maintain the def-use chain for atomic variables? So it is impossible to directly catch the fact that the load of x at the statement 'data1 = x; ' dependents on data4 (because of the statement x=data4 )? If I want to get such information, may be the only solution is to traverse all the predecessors of the statement 'data1 =

Hi, I'm trying to get the following loop to vectorize (simple reduction): unsigned int sum2(unsigned int *a, int len){ unsigned int s = 0; for (int i = 0; i < len; i += 4) s += *a++; return s; } The loop fails to vectorize because SCEV could not compute the loop exit count. It appears SCEV cannot handle the non-unit increment of the loop counter. Is this a known limitation of

It seems there is no -enable-iv-rewrite now in llvm3.2, and it suggest -enable-load-pre, but it still does not work. So, how to active the transform? -- View this message in context: http://llvm.1065342.n5.nabble.com/indvars-issues-tp4646p58587.html Sent from the LLVM - Dev mailing list archive at Nabble.com.

Hi Fellows, I am writing a pass that requires the DominatorTree pass. In the runOnFunction of my own pass, I call llvm::SplitBlock to split a block (%for.end) at it's first insert point. Then, when I dump my dominator tree immediately after, I can see the newly split %for.end.split, but its DFSNumIn and DFSNumOut are not properly updated in llvm::SplitBlock (i.e., still the initialized

Hi, The LangRef warns that "blockaddress(@function, %block)" has a limited and target-dependent applicability: https://llvm.org/docs/LangRef.html#addresses-of-basic-blocks But I wanted very much to save addresses of blocks in a global variable and so I did: % cat cond.c void foo(long *a) { if (a) *a = 0; } % clang -O1 -c cond.c -fsanitize-coverage=inline-8bit-counters,pc-table -S

Hi, Recently 10% performance regression on an important benchmark showed up after we integrated https://reviews.llvm.org/rL318299. The analysis showed that rL318299 triggered loop rotation on an multi exits loop, and the loop rotation introduced code layout issue. The performance regression is a side-effect of rL318299. I got two testcases a.ll and b.ll attached to illustrate the problem. a.ll

On Mon, Dec 18, 2017 at 5:46 PM Xinliang David Li <davidxl at google.com> wrote: > The introduction of cleanup.cond block in b.ll without loop-rotation > already makes the layout worse than a.ll. > > > Without introducing cleanup.cond block, the layout out is > > entry->while.cond -> while.body->ret > > All the arrows are hot fall through edges which is

I have a simple C++ class that looks like this: struct Foo { Thing *first; Blob *second; unsigned long third; }; Then I have a derived C++ class that look like this: struct Bar : Foo { long long fourth; } I generate JIT code to access 'fourth' from a Foo * as follows: BarPtr = CreateBitCast(FooPtr, BarPtrTy); FourthPtr = CreateConstGEP2_32(BarPtr, 0, 3); FourthValue =

Hi all, There might be a bug in DeadStoreElimination.cpp. This pass eliminates stores backwards aggressively in an end BB. It does not check dependencies on stores in an end BB though. For example, in this code snippet: ... 1. %sum.safe_r47.pre-phi = phi i64* [ %sum.safe_r47.pre, %entry.for.end_crit_edge ], [ %sum.safe_r42, %for.body ] 2. %call9 = call i32 @gettimeofday(%struct.timeval* %end,

Hi Andrew, Thanks a lot. But the function "DT->dominate(A,B)" decides the dominance relationship through comparing the DFS numbers, right? At least, in my example, when I check whether the newly split node (i.e., % *for.end.split*) DOMINATES the original node (I.e., %for.end), the answer is true, which is obviously wrong. Paul On Fri, Feb 14, 2014 at 1:59 AM, Andrew Trick