similar to: Help for DeadStoreElimination cross-block dependence

On Nov 4, 2009, at 7:21 AM, Hans Wennborg wrote: > Re-posting with better-looking code. Thanks, do you have a testcase showing what this does? -Chris > > Hans Wennborg wrote: >> The attached patch makes DeadStoreElimination able to remove stores >> in store-store dependencies when the operand types are equal, even >> if there is no TargetData available. >>

The attached patch makes DeadStoreElimination able to remove stores in store-store dependencies when the operand types are equal, even if there is no TargetData available. / Hans -------------- next part -------------- A non-text attachment was scrubbed... Name: DeadStoreElimination.patch Type: text/x-patch Size: 812 bytes Desc: not available URL:

Re-posting with better-looking code. Hans Wennborg wrote: > The attached patch makes DeadStoreElimination able to remove stores in > store-store dependencies when the operand types are equal, even if there > is no TargetData available. > > / Hans > > > ------------------------------------------------------------------------ > >

Sorry, I admit my e-mail was a bit unclear. Here is an example: declare void @foo() define void @f(i32* noalias %p) { store i32 1, i32* %p; <-- This is dead call void @foo() store i32 2, i32 *%p ret void } When run through ./llvm-as test.ll -o - | ./opt -O3 -S the dead store is not removed by the DSE pass. (The call to @foo is there to prevent InstCombine

Hi all, I am doing a project that requires counting the number of uses of a value only in all dominated blocks in a function. I checked the manual for llvm::User class, but only get this unsigned <http://llvm.org/test-doxygen/api/classunsigned.html> getNumUses <http://llvm.org/test-doxygen/api/classllvm_1_1Value.html#a380559e99b47632a34f74de7c1d03cc0> () const This gives me all the

Hans Wennborg wrote: > Sorry, I admit my e-mail was a bit unclear. > Here is an example: > > declare void @foo() > > define void @f(i32* noalias %p) { > store i32 1, i32* %p; <-- This is dead > call void @foo() > store i32 2, i32 *%p > ret void > } Hold up. Is this correct? "noalias: This indicates that the pointer

On Nov 5, 2009, at 1:59 PM, Hans Wennborg wrote: > My apologies for not replying sooner; I've been away from keyboard all > day today. > >> Thanks, applied here: >> http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20091102/090396.html >> >> >> I'd appreciate it if you could resend your other patches in patch >> format >> like

Hi everyone, I'm running R1.9.1 on RedHat Linux. I'm trying to read in a matrix file with 13956 by 858 dimensions. I realize this is pretty huge, though I think the amount of memory I have should be able to handle it. R reads the entire file and tells me "Read in 11974247 values". This is exactly one less value than what it should have read in (11974248 = 13956*856).

Hi, It looks like the DeadStoreElimination optimization doesn't work across BasicBlock boundaries. The project I'm working on (https://github.com/trailofbits/mcsema), would tremendously benefit from even simple cross-block DSE. There was a patch to do non-local DSE few years ago (http://lists.cs.uiuc.edu/pipermail/llvmdev/2010-January/028751.html), but seems that the patch was never

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,

On Thu, Oct 6, 2011 at 2:20 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Thu, Oct 6, 2011 at 2:12 PM, Zeng Bin <ezengbin at gmail.com> wrote: >> 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.

I wrote a pass(that is to be loaded by opt) that I would like to use in conjunction with MemoryDependenceAnalysis. I have tried using by including its header and adding this to my pass:        virtual void getAnalysisUsage(AnalysisUsage &AU) const {         errs() << "addRequired called\n";         AU.addRequired<MemoryDependenceAnalysis>();        } And in my

On Thu, Oct 6, 2011 at 2:12 PM, Zeng Bin <ezengbin at gmail.com> wrote: > 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,

Howdy, I'm working on writing a dependence analyzer (rather like what LoopDependenceAnalysis wants to be, except a bit more general). While this is a problem of many parts, I'm currently focusing on finding pairs of memory references to test for dependence. Consider this contrived C code: double test2(int n, double *restrict A, double *restrict B, bool flag) { if (flag) { A[0] =

On Oct 30, 2012, at 3:15 PM, Krzysztof Parzyszek <kparzysz at codeaurora.org> wrote: > On 10/30/2012 4:10 PM, Ashwin kumar wrote: >> >> Assertion failed: (PI && "Expected required passes to be initialized"), >> function schedulePass, file PassManager.cpp, line 597. >> >> >> I register the passes using RegisterPass function call.

It does not do anything. It is an abstract function which transforms a pointer and returns another pointer of the same type. It does not visit memory or capture the pointer parameter. On Thu, Oct 6, 2011 at 2:22 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Thu, Oct 6, 2011 at 2:20 PM, Eli Friedman <eli.friedman at gmail.com> > wrote: > > On Thu, Oct 6, 2011 at

On Sun, Jul 16, 2017, 12:45 PM Nuno Lopes <nunoplopes at sapo.pt> wrote: > >On 07/15/2017 04:51 AM, Nuno Lopes wrote: > >>> On 07/14/2017 04:37 PM, Nuno Lopes wrote: > >>>> Thank you all for your replies. > >>>> So here seems to be an agreement that the documentation for > >>>> PartialAlias is incorrect. > >>>>

If int_guard_load returns a pointer based on the passed-in pointer, it captures it (at least according to the definition of "capture" which NoCapture uses). -Eli On Thu, Oct 6, 2011 at 2:26 PM, Zeng Bin <ezengbin at gmail.com> wrote: > It does not do anything. It is an abstract function which transforms a > pointer and returns another pointer of the same type. It does not

Hello everyone, This week I was looking into the following example ( https://godbolt.org/z/uhgQcq) where two constants are written to a local array and an input argument, masked and shifted, is used to select between them. The possible values for the CC variable are 0 and 1, so I'm expecting that at the maximum level of optimizations the two constants are actually propagated, resulting in the

On Sat, Jul 15, 2017 at 5:35 AM, Hal Finkel <hfinkel at anl.gov> wrote: > > On 07/15/2017 04:51 AM, Nuno Lopes wrote: > >> On 07/14/2017 04:37 PM, Nuno Lopes wrote: >>> >>>> Thank you all for your replies. >>>> So here seems to be an agreement that the documentation for >>>> PartialAlias is incorrect. >>>>