similar to: [LLVMdev] type of the store operand

Zheng Wang wrote: > Hiya, > > I want to know what's the type of the operand (value) along with the > store instruction. For example, the following instruction store the > content in an integer type pointer scevgep99.1 to the address another > integer pointer points to. > > *"store i8* %scevgep99.1, i8** %scevgep92.1, align 4"* > > It seems there is no

Hello, I've been redirected from cfe-dev, as code optimizations in clang are done in llvm layer. I'm investigating how optimized code clang generates, and have come across such an example: I have two procedures: void exec0(const int *X, const int *Y, int *res, const int N) { int t1[N],t2[N],t3[N],t4[N],t5[N],t6[N]; for(int i = 0; i < N; i++) { t1[i] = X[i]+Y[i];

I'm hitting a strange pointer aliasing "bug". Here is a test case : /* SOURCE CODE */ #define little_list_size 8 class LittleList1 { public: int _length; double _data[ little_list_size ]; LittleList1( int length ) { _length = length; for( int i=0; i<length; i++ ) _data[i] = 0; } }; class LittleList2 { public: int _length; double _data[ little_list_size ];

Hi, The compilation of the following code void f(int *a, int b[], int n) { int i; for(i=0; i< n; ++i) a[i] = b[i]; } gives the IR: define void @f(i32* nocapture %a, i32* nocapture %b, i32 %n) nounwind { %1 = icmp sgt i32 %n, 0 br i1 %1, label %.lr.ph, label %._crit_edge .lr.ph: ; preds = %0 %tmp = zext i32 %n to i64 br label %2 ;

On Wed, Sep 2, 2015 at 5:36 AM, James Molloy <james at jamesmolloy.co.uk> wrote: > Hi, > > Coremark really isn't a good enough test - have you run the LLVM test suite > with this patch, and what were the performance differences? For the test suite single source benches, the 235 tests improved performance, 2 regressed and 705 were unchanged. That seems very optimistic.

Even after all the sequence of commands below bit-code is not showing any effect of loop-unrolling *manish at manish:~/Test2$ llvm-gcc-4.2 -O2 -emit-llvm Hello.c -c -o Hello.bc* *manish at manish:~/Test2$ opt-2.8 -loops Hello.bc -o Hello1.bc* *manish at manish:~/Test2$ opt-2.8 -loopsimplify Hello1.bc -o Hello2.bc* *manish at manish:~/Test2$ opt-2.8 -indvars Hello2.bc -o Hello3.bc* *manish at

1. You should run the passes in the same opt command, for passes like loops which is an analysis pass provides results to the following passes. 2. You can pass a -debug flag to opt to see the some debugging info. 3. I tried this opt -mem2reg -loops -loopsimplify -loop-unroll -unroll-count=3 -debug loop.o -o tt.bc and got this message. Loop Size = 14 Can't unroll; loop not terminated by

Hi all, The attached LLVM assembly file fails to generate x86 code when compiled using llc. compilation command - ../llvm-build/bin/llc -filetype=asm -march=x86-64 -mcpu=core-avx2 ex4.ll The error message is, LLVM ERROR: Cannot select: t95: v8f32 = X86ISD::SUBV_BROADCAST t17 t17: v4f32,ch = load<LD16[%scevgep](tbaa=<0x4dbcd98>)> t0, t16, undef:i64 t16: i64 = add t2,

Dear llvm contributors, Could you please advise me where objects of MemoryLocation class are created for ‘llvm.memset.*‘ intrinsics? In the Bug 23077 (https://llvm.org/bugs/show_bug.cgi?id=23077) the AliasSetTracker constructs 128 alias sets for 0 pointer values, which contain only unknown instructions. In this case, all unknown instructions, which are added to new alias sets in the

I updated to the latest revision and now llvm does not build and quits cmake with CMake Error at cmake/modules/LLVMProcessSources.cmake:83 (message): Found unknown source file ../llvm-revec/lib/CodeGen/MachineFunctionAnalysis.cpp Please update ../llvm-revec/lib/CodeGen/CMakeLists.txt Thanks On Sat, Sep 3, 2016 at 2:09 AM, Craig Topper <craig.topper at gmail.com> wrote: >

On Mon, Apr 27, 2015 at 4:21 PM, Daniel Berlin <dberlin at dberlin.org> wrote: > You can't win here (believe me, i've tried, and better people than me have > tried, for years :P). > No matter what you do, the partitioning will never be 100% precise. The > only way to solve that in general is to pairwise query over the > partitioning. > > Your basic problem is

In your example the the number of iterations is known -- it is N. It is not known at compile time, but it's known at run-time before you enter the loop. So you can do transforms like if( N < threshold ) copy of loop optimized for small iterations count; else copy of loop optimized for large iterations count; But you are right, in general, the number of iterations in unknown. I think Khaled

On Jun 29, 2010, at 7:08 AM, ether zhhb wrote: > > why computeSCEVAtScope not try to get the operands in the current > scope like the function do with SCEVCommutativeExpr, like: > > if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(V)) { > if (!L || !AddRec->getLoop()->contains(L)) { > ... > // Then, evaluate the AddRec. >

On Wed, Jun 16, 2010 at 1:39 PM, Pierre C <lists at peufeu.com> wrote: > > I'm hitting a strange pointer aliasing "bug". Here is a test case : > > /* SOURCE CODE */ > > #define little_list_size 8 > > class LittleList1 { > public: >        int     _length; >        double  _data[ little_list_size ]; > >        LittleList1( int length ) >

hi all, i have SCEVAddRec {{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1> where Loop0 and Loop1 are brothers (loops at the same level of the loopnest), and Loop0 have a computable backedge taken count. when i call getSCEVAtScope({{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1> , Loop1), it just give me a {{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1>, instead of

Hi, You might want to try running -loops -loop-simplify before loop unroll. >From loop simplify.cpp This pass performs several transformations to transform natural loops into a00011 // simpler form, which makes subsequent analyses and transformations simpler and00012 // more effective. Arushi On Tue, May 3, 2011 at 2:17 PM, Manish Gupta <mgupta.iitr at gmail.com> wrote: > You

On 07/04/2013 01:39 PM, Stéphane Letz wrote: > Hi, > > Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be vectorized with opt -O3 -vectorize-loops. So our guess is that our generated LLVM IR lacks some

Hi, Our DSL can generate C or directly generate LLVM IR. With LLVM 3.3, we can vectorize the C produced code using clang with -O3, or clang with -O1 then opt -O3 -vectorize-loops. But the same program generating LLVM IR version cannot be vectorized with opt -O3 -vectorize-loops. So our guess is that our generated LLVM IR lacks some informations that are needed by the vectorization passes to

On 12 June 2010 00:51, Eli Friedman <eli.friedman at gmail.com> wrote: > On Fri, Jun 11, 2010 at 3:28 PM, Bill Hart <goodwillhart at googlemail.com> wrote: >> Hi Eli, >> >> On 11 June 2010 22:44, Eli Friedman <eli.friedman at gmail.com> wrote: >>> On Fri, Jun 11, 2010 at 10:37 AM, Bill Hart <goodwillhart at googlemail.com> wrote:

I was able to get the loop to increment from -999 to 0 using IR directly. That got rid of the cmpq. The carry i was after was able to be obtained using the intrinsic @llvm.uadd.with.overflow.i64, however there is no way to add with carry and have it realise that the resulting *carry out* cannot exceed 1. It actually writes the carry to a byte, and then uses logical operations on it, which slows