similar to: [LLVMdev] constructing 'for' statement from LLVM bitcode

Wow... Thank you so much for this. I'll try this one. Thanks again, Wojciech. SJL ---- Original message ---- >Date: Sat, 15 Sep 2007 15:07:34 +0200 >From: Wojciech Matyjewicz <wmatyjewicz at fastmail.fm> >Subject: Re: [LLVMdev] constructing 'for' statement from LLVM bitcode >To: LLVM Developers Mailing List <llvmdev at cs.uiuc.edu> > >Hi, >

Hello, guys. I am trying to construct higher-level 'for' from the low-level LLVM bitcode(ver 1.9). It's partly successful thanks to David A. Greene's advice suggested to use Control Dependence Graph(CDG). I could find which BB contributes to form which loop with CDG. For example, for this simple function: ----------------------------------------------------------- void bsloop(int

Hello, guys. I just tested -reg2mem pass to see how it changes my bitcode. E.g., for the following simple C code: ------------------------------------------------------------- int foo() { int i,j; int sum = 0; for (i=0; i<10; i++) { sum += i; for (j=0; j<3; j++) sum += 2; } return sum; } ------------------------------------------------------------- I could get the

---------- Forwarded message ---------- From: Ryan Taylor <ryta1203 at gmail.com> Date: Mon, Nov 21, 2011 at 10:30 AM Subject: Re: [LLVMdev] Order of Basic Blocks To: Benjamin Kramer <benny.kra at googlemail.com> This worked, though the RPO_iterator apparently wasn't what I was looking for anyways, it seems it doesn't rreally go top->down. I have a simple example code,

Thank you for this comment, Mike. So... your suggestion is to make a valid transform for each loop like: >for (;C;) { > S >} > >is to transform: > >top: >if (!C) goto end; > S >goto top; >end: For now, my code is incomplete so not ready to present for audit yet but I hope it asap. In fact, I couldn't understand what you said: >The cost of the .pdf

Hi, It looks like PDT.getRootNode() returns NULL for: define fastcc void @c974001__lengthy_calculation. 1736(%struct.FRAME.c974001* nocapture %CHAIN.185) noreturn { entry: br label %bb bb: br label %bb } Isn't it a bug in PostDominatorTree? Please note that this crashes: opt -postdomtree -debug dom_crash.bc I think this should be reported as a bug, -Jakub On Sep 3, 2009, at

Jakub Staszak wrote: > Hi, > > It looks like PDT.getRootNode() returns NULL for: > > define fastcc void @c974001__lengthy_calculation. > 1736(%struct.FRAME.c974001* nocapture %CHAIN.185) noreturn { > entry: > br label %bb > > bb: > br label %bb > } > > > Isn't it a bug in PostDominatorTree? > > Please note that this crashes: >

Hello, Bug is already fixed by Chris (see: http://llvm.org/bugs/show_bug.cgi?id=4915) . I added getRootNode() == NULL condition to my patch. It's not a great solution, but it is enough for now I think. New patch attached. -Jakub -------------- next part -------------- A non-text attachment was scrubbed... Name: dse_ssu-2.patch Type: application/octet-stream Size: 17762 bytes Desc: not

Hi, I've stumbled upon a case where I think gvn does a bad (wrong) optimization. It's a bit messy to debug though so I'm not sure if I should just write a PR about it a let someone who knows the code look at it instead. Anyway, for the bug to trigger I need to run the following passes in the same opt invocation: -sroa -instcombine -simplifycfg -instcombine -gvn The problem

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:

On 08/05/2010 06:46 AM, Wenbin Zhang wrote: > Hi all, > I'm using postDominatorTree to do some program analysis. My code works > well for small tests, but when I run it on real applications, the > following error occurs: > /Inorder PostDominator Tree: DFSNumbers invalid: 0 slow queries. > [1] <<exit node>> {0,21} > [2] %bb1 {1,2} > [2] %bb {3,4} > [2]

I'll try the trunk, as well as check my code again. If indeed it's not fixed, I'll try to post a triggering case here. Thanks for the advice~ Best, --Wenbin ----- Original Message ----- From: "Tobias Grosser" <grosser at fim.uni-passau.de> To: "Wenbin Zhang" <zhangwen at cse.ohio-state.edu> Cc: <llvmdev at cs.uiuc.edu> Sent: Thursday, August

Wenbin Zhang wrote: > I'll try the trunk, as well as check my code again. If indeed it's not > fixed, I'll try to post a triggering case here. > Thanks for the advice~ > Did you run the -mergereturn pass (it might also be called UnifyExitNodes in the source code)? This is the pass that ensures that each function has exactly one basic block that returns control to the

I have what appears to be a bug in LLVM... I'm deeply hesitant to label it a bug, given my lack of experience with LLVM, but the behaviour of this fragment strongly suggests a bug. In particular, compiling and running this fragment using a fresh SVN build yields this stderr: uccello:/tmp clements$ lli a.out.bc 0 lli 0x005e72b6 char const* std::find<char const*,

[+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

False Alarm!! Still don't know how to do it! I am trying to write a transformation pass to extract a loop body into a function. For example: The Loop in question is: for (i2 = 0; i2 < LOOP_SIZE; i2++) { A[B[i2]] = 2 * B[i2]; } The IR for which is: bb13: ; preds = %bb13, %bb %i2.0.reg2mem.0 = phi i32 [ 0, %bb ], [ %indvar.next62, %bb13 ] ; <i32>

Hi all, I have problem with ExtractCodeRegion (CodeExtractor.cpp). My original program is as follows. bb: ... %tmp.15 = load %struct.MYSQL_ROWS** %3, align 4 ... bb1: ... %tmp.1 = load %struct.MYSQL_ROWS** %6, align 4 ... bb4: ; preds = %bb1, %bb, %entry %tmp.0 = phi %struct.MYSQL_ROWS* [ null, %entry ], [ %tmp.15, %bb ], [ %tmp.1, %bb1 ]

Hello, I have two for loops (one inside the other), that after indvars, looprotate, etc. (the important here is the loop rotate), is similar to this (I've stripped the real operations): define i32 @f() nounwind { entry: br label %bb1 bb1: ; preds = %bb3, %bb1, %entry %i.0.reg2mem.0.ph = phi i32 [ 0, %entry ], [ %i.0.reg2mem.0.ph, %bb1 ], [ %indvar.next9, %bb3 ] ;

Hi, I would like some help regarding the LSR pass. It seems that it likes to duplicate address calculations as in the case above, which is highly undesirable on my target. I wonder if there is any way to tell LSR to not duplicate the code in cases like this? Or could I perhaps run CSE after LSR again? What is the logic behind this transformation? It seems that a LSR pass should not insert a

Try breaking the critical edges (-break-crit-edges). This way, a new block will be created between BB13 and BB11 (call this BB11.break) and BB15 and BB12 (call this BB12.break). The predecessors of the dominance frontier will, thus, be BB11.break, BB12.break, and BB14. When we enter through a block with a call to malloc(), we will end up in one of the blocks in the dominance frontier (kind of).