search for: getelementptrs

The loads, stores and float arithmetic in attached function should be completely vectorizable. The bb-vectorizer does a good job at first, but from instruction %96 on it messes up by adding unnecessary vectorshuffles. (The function was designed so that no shuffle would be needed in order to vectorize it). I tested this with llvm 3.6 with the following command:

I seem to have problem to get the SLP vectorizer to make use of the full 8 floats available in a SIMD vector on a Sandy Bridge CPU with AVX. The function is attached, the CPU flags are: flags : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good

MCJIT when lowering to x86-64 generates a MOVAPS (Move Aligned Packed Single-Precision Floating-Point Values) on a non-aligned memory address: movaps 88(%rdx), %xmm0 where %rdx comes in as a function argument with only natural alignment (float*). This x86 instruction requires the memory address to be 16 byte aligned which 88 plus something aligned to 4 byte isn't. Here the

Hi guys, I think I have run into another CachingMemorySSAWalker cache bug. It's a bit tricky to reproduce, so I'd like to start by trying to show you what is happening when running EarlyCSE with my local changes to use MemorySSA. I've attached a debug log that shows that the value returned by getClobberingMemoryAccess(Inst) after a call to removeMemoryAccess is wrong. The

On 7 August 2014 17:33, Chad Rosier <mcrosier at codeaurora.org> wrote: > You might consider filing a bug (llvm.org/bugs) requesting a flag, but I > don't know if the code owners want to expose such a flag. I'm not sure that's a good idea as a raw access to that limit, as there are no guarantees that it'll stay the same. But maybe a flag turning some

Hi, GVN seems to be running in an infinite loop on my example. I have attached the output of one iteration. I cant seem to reduce the testcase either. Any pointers to how to reduce the test case. THanks, Arushi GVN iteration: 8 GVN WIDENED LOAD: %0 = load i8* getelementptr inbounds (%struct.CHESS_POSITION* @search, i64 0, i32 23), align 2, !dbg !875 TO: %1 = load i16* bitcast (i8*

Something must be wrong, more probable on my side. So the C source code is unchanged, I just did another experiment to first extract all the GEPs in the code, and call AliasAnalysis::alias on each pair of GEPs. Here is the code: AliasAnalysis &AA = getAnalysis<AliasAnalysis>(); TargetData &TD = getAnalysis<TargetData>(); for (Module::iterator it = M.begin();

Just want to test out the LLVM's AliasAnalysis::getModRefInfo API. The input C code is very simple: void foo(int *a, int *b) { for(int i=0; i<10; i++) b[i] = a[i]*a[i]; } int main() { int a[10]; int b[10]; for(int i=0; i<10; i++) a[i] = i; foo(a,b); return 0; } Obviously, for "foo", it only reads from array "a" and only writes to array

Thanks Duncan! You are right! If I type the command "opt -basicaa -mypass ...", then the output makes sense. Now, how can you specify which AA to use in the code? Regards, Welson On Thu, Feb 16, 2012 at 12:05 PM, Duncan Sands <baldrick at free.fr> wrote: > Hi Welson, the default alias analysis is -no-aa. As the name suggests it > just returns MayAlias for everything.

Hi Welson, the default alias analysis is -no-aa. As the name suggests it just returns MayAlias for everything. Maybe you are using that one? Best wishes, Duncan.

On May 3, 2011, at 3:25 PM, Arushi Aggarwal wrote: > Hi, > > GVN seems to be running in an infinite loop on my example. I have attached the output of one iteration. I cant seem to reduce the testcase either. > > Any pointers to how to reduce the test case. Bugzilla can reduce testcases that cause infinite loops (it has a -timeout flag), I'd try it. Even if this doesn't

Hi, I have experimented with enabling the LoopVectorizer for SystemZ. I have come across a loop which, when vectorized, seems to have been poorly generated. In short, there seems to be a completely unnecessary sequence of shufflevector instructions, that doesn't get optimized away anywhere. In other words, there is a shuffling so that leads back to the original vector: [0 1 2 3

Hi Arnold, Thanks for your reply. I tried test case as suggested by you. *void foo(int *a, int *sum) {*sum = a[0]+a[1]+a[2]+a[3]+a[4]+a[5]+a[6]+a[7]+a[8]+a[9]+a[10]+a[11]+a[12]+a[13]+a[14]+a[15];}* so that it has a 'store' in its IR. *IR before vectorization :*target datalayout = "e-m:e-p:32:32-f64:32:64-f80:32-n8:16:32-S128" target triple =

Hi Duncan, A DragonEgg/GCC-related question: do you know where these strange FRAME tokens originate from (e.g. %struct.FRAME.matmul)? Compiling simple Fortran code with DragonEgg: > cat matmul.f90 subroutine matmul(nx, ny, nz) implicit none integer :: nx, ny, nz real, dimension(nx, ny) :: A real, dimension(ny, nz) :: B real, dimension(nx, nz) :: C integer :: i, j, k real,

Hi all, I'm writting following LLVM assembly: ; ModuleID = 'structaccess.ll' %struct._anon0 = type <{ i32, i32, i32 }> @s = common global %struct._anon0 zeroinitializer define arm_aapcscc void @foo() nounwind { L.entry: store i32 5, i32* getelementptr inbounds (%struct._anon0* @s, i32 0, i32 0) store i32 10, i32* getelementptr inbounds (%struct._anon0* @s, i32 0, i32 1)

Hello everyone, please I need your help. To reproduce my problem I created simple pass for backends (TestPass.cpp in attached files). That pass I call from Mips backend in this way (MipsTargetMachine.cpp): bool MipsPassConfig::addPreRegAlloc() { addPass(createTestPass()); return false; } The problem becomes, when I am trying compile file ldtoa.ll (in attached files). Compiling

Hi Nadav, Thanks for the quick reply !! Ok, so as of now we are lacking capability to handle flat large reductions. I did go through function vectorizeChainsInBlock() (line number 2862). In this function, we try to vectorize if we have phi nodes in the IR (several if's check for phi nodes) i.e we try to construct tree that starts at chains. Any pointers on how to join multiple trees? I

Hmm... found an interesting issue: Given: %2 = getelementptr inbounds %UodStructType* %0, i32 0, i32 0 store i8 1, i8* %2, align 8 %3 = getelementptr inbounds %UodStructType* %0, i32 0, i32 1 store i8 2, i8* %3, align 1 %4 = getelementptr inbounds %UodStructType* %0, i32 0, i32 2 store i8 3, i8* %4, align 2 %5 = getelementptr inbounds %UodStructType* %0, i32 0, i32 3

Hi, I am trying to understand LLVM vectorization implementation and was looking into both loop and SLP vectorization. test case 1: *int foo(int *a) {int sum = 0,i;for(i=0; i<16; i++) sum += a[i];return sum;}* This code is vectorized by loop vectorizer where we calculate scalar loop cost as 4 and vector loop cost as 2. Since vector loop cost is less and above reduction is legal to

Le 29 mai 2010 à 01:08, Bill Wendling a écrit : > Hi Stéphane, > > The SSE support is the LLVM backend is fine. What is the code that's generated? Do you have some short examples of where LLVM doesn't do as well as the equivalent scalar code? > > -bw > > On May 28, 2010, at 12:13 PM, Stéphane Letz wrote: We are actually testing LLVM for the Faust language