similar to: One more No-alias case on Alias analysis

On 06/11/2018 02:33 PM, Friedman, Eli via llvm-dev wrote: > On 6/11/2018 10:06 AM, jingu at codeplay.com via llvm-dev wrote: >> Hello All, >> >> I have met one may-alias case from llvm's alias analysis. The code >> snippet is as following: >> >> char buf[4]; >> >> void test (int idx) { >> char *a = &buf[3 - idx]; >> char *b =

Hello All, I have a question about a May-alias case. Let's look at one simple C example. char *buf[4]; char c; void test(int idx) {   char *a = buf[3 - idx];   char *b = buf[idx];   *a = *b;   c++;   *a = *b; } We can imagine the second "*a = *b" could be removed. Let's look at the IR snippet with -O3 for above example.   1 define void @test(i32 %idx) {   2 entry:  

Hello All, I have met a case with restrict keyword and I have a question about it. Let's look at a simple example. char buf[4]; void test(char *restrict a, char *restrict b, int count) {   for (unsigned i = 0; i < count; i++) {     *a = *b;     a++;     b++;     buf[i] = i;   } } I think there are no aliasing among pointers such as 'a', 'b' and 'buf'

Please open a bugzilla ticket and attach your testcase. It will allow us to debug and fix the problem. Thanks - Elena From: JinGu [mailto:jingu at codeplay.com] Sent: Saturday, September 16, 2017 00:38 To: Demikhovsky, Elena <elena.demikhovsky at intel.com>; daniel_l_sanders at apple.com <daniel_l_sanders at apple.com>; Jon Chesterfield <jonathanchesterfield at

Hi All, I have a question about TableGen RegisterClass definition. I need to map different size of MVTs into a register class as below. def TestReg : RegisterClass<"Test", [v8i32, v4i32], ...> When I look at TableGen and CodeGen, it looks the types are used as following: 1. MCRegisterClass's RegSize and Alignment 2. SpillSize in TableGen 3. Type constraint for instruction

> extends the elements to 8bit and stores them on stack. Store is responsible for zero-extend. This is the policy... - Elena -----Original Message----- From: jingu at codeplay.com [mailto:jingu at codeplay.com] Sent: Friday, September 15, 2017 17:45 To: llvm-dev at lists.llvm.org; Demikhovsky, Elena <elena.demikhovsky at intel.com>; daniel_l_sanders at apple.com Subject: Re: Question

> so I think we need to use non-extending load for element size less than 8bit on "DAGTypeLegalizer::SplitVecOp_EXTRACT_VECTOR_ELT" like this roughly. > if (N->getOperand(0).getValueType().getVectorElementType().getSizeInBits() < 8) { > return DAG.getLoad(N->getValueType(0), dl, Store, StackPtr, MachinePointerInfo()); > } else { > return

On Feb 19, 2014, at 1:54 PM, jingu <jingu at codeplay.com> wrote: > Hi Andy, > > I am trying to schedule and packetize instructions for VLIW at post-RA > stage or final codegen stage, where code transformations are not allowed > any more, because hardware can not resolve resource conflict. There is a > simple example as following: > > ADD dest_reg1, src_reg1,

On Mar 4, 2014, at 10:05 AM, Pete Cooper <peter_cooper at apple.com> wrote: > > On Mar 3, 2014, at 2:21 PM, Andrew Trick <atrick at apple.com> wrote: > >> >> On Mar 3, 2014, at 8:53 AM, Pierre-Andre Saulais <pierre-andre at codeplay.com> wrote: >> >>> Hi Andrew, >>> >>> We are currently using a custom model where

Hi Matthias, >Jingu: Why do you even want a configuration that has LLVM_ENABLE_DUMP but does not have asserts enabled at the same time? My colleague and I am doing custom project using clang/llvm. We have always wanted to use the IR Value's dump() to check our implementation correctly with Debug, Release and another builds. We thought the LLVM_ENABLE_DUMP is for it. If Chris fixes

Presently several of our headers have definitions like: #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) void dump() const; #endif Would it make sense to modify the build system to define LLVM_ENABLE_DUMP in config.h on debug builds? Then we could wrap dump methods just based on LLVM_ENABLE_DUMP instead of two variables. -Chris > On Apr 10, 2017, at 1:34 PM, Robinson, Paul via llvm-dev

On Mar 3, 2014, at 8:53 AM, Pierre-Andre Saulais <pierre-andre at codeplay.com> wrote: > Hi Andrew, > > We are currently using a custom model where scheduling information is attached to each MCInstrDesc through tablegen, and we're trying to move to one of LLVM's models. > > To expand on what JinGu mentioned, our target has explicit ports that are used to read and

Hi Eli, Thanks for good comment! I missed to initalize the buf. Let's slightly change the example as below. char subbuf1[2]; char subbuf2[2]; char subbuf3[2]; char subbuf4[2]; char *buf[4] = {subbuf1, subbuf2, subbuf3, subbuf4}; char c; void test(int idx) { char *a = buf[3 - idx]; char *b = buf[idx]; *a = *b; c++; *a = *b; } I think we can say the 'buf' does not

Hi, I am trying to get the alias info for the following code. The alias analysis returns "MayAlias" for arrays "A" and "B" in both the functions instead of "NoAlias". What passes should I run in opt before the alias analysis pass to get the accurate result? Example: //Note: static and called by func() only. static int sum(int *A, int *B) { int i = 0,

Hi, LLVM community: I found basicaa seems not to tell must-not-alias for __restrict__ arguments in c/c++. It only compares two pointers and the underlying objects they point to. I wonder how clang does alias analysis for c/c++ keyword restrict. let assume we compile the following code: $cat myalias.cc float foo(float * __restrict__ v0, float * __restrict__ v1, float * __restrict__ v2, float *

Hi all, I have a compilation failure with 'insert' member function of SmallPtrSetImpl class because the return value is changed from r222334. But the comment of the function is same with before as follows: /// insert - This returns true if the pointer was new to the set, false if it /// was already in the set. std::pair<iterator, bool> insert(PtrType Ptr) { auto p

> On Apr 7, 2017, at 4:45 PM, Matthias Braun via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > I think the idea is to keep NDEBUG out of headers when possible. So I think this should better be something like: > > -#ifndef NDEBUG > void dumpUses(unsigned RegNo) const; > -#endif > > to be inline with various other dumpers (like MachineInstr::dump(),

> On Apr 10, 2017, at 12:37 PM, Matthias Braun <mbraun at apple.com> wrote: > > The situation is not consistent. Yes there are several places where we have the #if in the headers however there are far more cases where it is not. Some points here: > > - This whole LLVM_DUMP_FUNCTION/LLVM_ENABLE_DUMP is about enabling the linker to strip (or not strip) the dumping function in

Hi All, I have a question about splitting 'EXTRACT_VECTOR_ELT' with 'v2i1'. I have a llvm IR code snippet as following: llvm IR code snippet: for.body: ; preds = %entry, %for.cond %i.022 = phi i32 [ 0, %entry ], [ %inc, %for.cond ] %0 = icmp ne <2 x i32> %vecinit1, <i32 0, i32 -23> %1 = extractelement <2 x i1>

Hi, Your problem is that the function arguments, which are makes as noalias, are not being directly used as the base objects of the array accesses: > %v0.addr = alloca float*, align 8 > %v1.addr = alloca float*, align 8 > %v2.addr = alloca float*, align 8 > %t.addr = alloca float*, align 8 ... > store float* %v0, float** %v0.addr, align 8 > store float* %v1, float** %v1.addr,