similar to: If there are some passes in LLVM do the opposite of the SROA(Scalar Replacement of Aggregates) pass

Hello, I am performing alias analysis toward the following simple code: struct MyStruct { int * f1; int * f2; }; void NOALIAS(void* p, void* q){ } int main() { struct MyStruct s[2]; int a,b; s[0].f1 = &a; s[1].f1 = &b; NOALIAS(s[a].f1, s[b].f2); return 0; } When I use the following command to generate .bc code and conduct alias analysis: clang -c -emit-llvm t.c -O2 opt -basicaa

Hey Matt, That's awesome. Thank you very much for all the information and clarification! Just a few follow up questions. Could you kindly shed some lights on it? Thank you! 1. I tried to tweak the code in the following way: - Clang [-> LLVM-IR]: https://llvm.godbolt.org/z/n9rGrs - [LLVM-IR ->] opt: https://llvm.godbolt.org/z/Uc6h5Y And i note that the outputs are: Alias sets for

Hi I have this program in which fooBuf can only take on NULL or the address of local_fooBuf, and fooBuf and local_fooBuf have scope of the foo function. Therefore there is no way for the fooPtr argument to alias with fooBuf. However, LLVM basicaa and globalsmodref-aa say the 2 pointers may alias. I am thinking whether i should implement a limited form of point-to alias on the fooBuf pointer in

Sent from my iPhone... On Jun 25, 2013, at 8:14 AM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- >> >> >> >> On Jun 24, 2013, at 4:24 PM, Hal Finkel < hfinkel at anl.gov > wrote: >> >> >> >> >> Indvars should ideally preserve NSW flags whenever possible. However, >> we don't want to

----- Original Message ----- > From: "Hal Finkel" <hfinkel at anl.gov> > To: "Chandler Carruth" <chandlerc at google.com> > Cc: llvmdev at cs.uiuc.edu > Sent: Thursday, July 16, 2015 1:58:02 AM > Subject: Re: [LLVMdev] Improving loop vectorizer support for loops > with a volatile iteration variable > ----- Original Message ----- > >

----- Original Message ----- > > > > On Jun 24, 2013, at 4:24 PM, Hal Finkel < hfinkel at anl.gov > wrote: > > > > > Indvars should ideally preserve NSW flags whenever possible. However, > we don't want to rely on SCEV to preserve them. SCEV expressions are > implicitly reassociated and uniqued in a flow-insensitive universe > independent of the

> -----Original Message----- > From: Michele Scandale [mailto:michele.scandale at gmail.com] > Sent: Saturday, August 10, 2013 6:29 AM > To: Micah Villmow > Cc: LLVM Developers Mailing List > Subject: Re: [LLVMdev] Address space extension > > On 08/10/2013 02:47 PM, Micah Villmow wrote: > > Michele, > > The information you are trying to gather is fundamentally

Hi Gerolf, I think we have several (perhaps separable) issues here: 1. Do we have a canonical form for loops, preserved through the optimizer, that allows naturally-constructed loop nests to remain separable? 2. Do we forbid non-lowering transformations that turn vectorizable loops into non-vectorizable loops? 3. How do we detect cases where transformations cause a negative answer to either

Hi, Scalar evolution seems to be wrapping around the trip count in the following loop. void add (int *restrict a, int *restrict b, int *restrict c) { char i; for (i = 0; i < 255; i++) a[i] = b[i] + c[i]; } When I run scalar evolution on the bit code, I get a backedge-taken count which is obviously wrong. $> cat loop.ll ; Function Attrs: nounwind define void @add(i32* noalias

Hi folks, Moving the discussion to llvm.dev. None of the changes we talked earlier help. Find attached the C source code that you can use to reproduce the issue. clang --target=aarch64-linux-gnu -c -mcpu=cortex-a57 -Ofast -fno-math-errno test.c -S -o test.s -mllvm -debug-only=licm LICM hoisting to while.body.lr.ph: %21 = load double** %arrayidx8, align 8, !tbaa !5 LICM hoisting to

Can you send me actual LLVM IR or a preprocessed source from using -E? I don't have a machine handy that has headers that target that arch. On Tue Jan 13 2015 at 4:33:29 PM Daniel Berlin <dberlin at dberlin.org> wrote: > Anything other than noalias or mustalias should be getting passed down the > stack, so either that is not happening or CFL aa is giving better answers > and

Inline - George > On Jan 14, 2015, at 10:49 AM, Daniel Berlin <dberlin at dberlin.org> wrote: > > > >> On Tue, Jan 13, 2015 at 11:26 PM, Nick Lewycky <nlewycky at google.com> wrote: >>> On 13 January 2015 at 22:11, Daniel Berlin <dberlin at dberlin.org> wrote: >>> This is caused by CFLAA returning PartialAlias for a query that BasicAA can

On 13 January 2015 at 22:11, Daniel Berlin <dberlin at dberlin.org> wrote: > This is caused by CFLAA returning PartialAlias for a query that BasicAA > can prove is NoAlias. > One of them is wrong. Which one? I'm not sure from your description that this is a chaining issue. PartialAlias doesn't chain and isn't supposed to, it's a final answer just like NoAlias and

Oh, sorry, i didn't rebase it when i changed the fix, you would have had to apply the first on top of the second. Here is one against HEAD On Wed, Jan 14, 2015 at 12:32 PM, Ana Pazos <apazos at codeaurora.org> wrote: > Daniel, your patch does not apply cleanly. Are you on the tip? > > The code I see there is no line if (QueryResult == MayAlias|| QueryResult == PartialAlias)

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.

Hello, How can I compute the functions on the loop iterators used as array indices?  For example: for i = 0, N       for j = 0, M             A[2*i + j - 10] = ...  Can I obtain that this instruction A[2*i + j - 10]= .. always accesses memory using a function       f(i,j)   =   2*i + j - 10 + base_address_of_A If I run the scalar evolution pass on this code I obtain: %arrayidx =

Yes. I've attached an updated patch that does the following: 1. Fixes the partialalias of globals/arguments 2. Enables partialalias for cases where nothing has been unified to a global/argument 3. Fixes that select was unifying the condition to the other pieces (the condition does not need to be processed :P). This was causing unnecessary aliasing. 4. Adds a regression test to

I have three modules: ----------------------------------------------------------------- s1.ll: %0 = type <{ i32, i32 }> define void @s1(%0* byval %myStruct) nounwind { return: ret void } ----------------------------------------------------------------- s2.ll: %0 = type <{ i32, i32 }> define void @s2(%0* byval %myStruct) nounwind { return: ret void }

On 07/27/2011 03:11 PM, Jimborean Alexandra wrote: > Hello, > > How can I compute the functions on the loop iterators used as array > indices? > > For example: > > for i = 0, N > for j = 0, M > A[2*i + j - 10] = ... > > Can I obtain that this instruction A[2*i + j - 10]= .. always accesses > memory using a function f(i,j) = 2*i + j - 10 + base_address_of_A

Hi Xiaoyi, this looks like a bug to me - please file a bug report. Ciao, Duncan. On 01/11/12 04:35, Guo, Xiaoyi wrote: > I have three modules: > ----------------------------------------------------------------- > s1.ll: > > %0 = type <{ i32, i32 }> > > define void @s1(%0* byval %myStruct) nounwind { > return: > ret void > } >