similar to: [LLVMdev] Loop vectorizer dosen't find loop bounds

Bingo! That works (when coming from C source) Now, I have a serious problem. I am not coming from C but I build the function with the builder. I am also forced to change the signature and load the pointers a,b,c afterwards: define void @bar([8 x i8]* nocapture readonly %arg_ptr) #0 { entrypoint: %0 = bitcast [8 x i8]* %arg_ptr to i32* %1 = load i32* %0, align 4 %2 = getelementptr [8 x

----- Original Message ----- > I am trying to vectorize the function > > void bar(float *c, float *a, float *b) > { > const int width = 256; > for (int i = 0 ; i < 256 ; ++i ) { > c[ i ] = a[ i ] + b[ i ]; > c[ width + i ] = a[ width + i ] + b[ width + i ]; > } > } > > using the following commands > > clang

Thanks for the alternatives! I am trying the 'extracting sub-function' approach. However, it seems I can't get the 'subfunction' to pass the verifier. This is my subfunction: define void @main_extern([8 x i8]* %arg_ptr) { entrypoint: %0 = getelementptr [8 x i8]* %arg_ptr, i32 0 %1 = bitcast [8 x i8]* %0 to i64* %2 = load i64* %1 %3 = getelementptr [8 x i8]*

----- Original Message ----- > Bingo! That works (when coming from C source) > > Now, I have a serious problem. I am not coming from C but I build the > function with the builder. I am also forced to change the signature > and > load the pointers a,b,c afterwards: > > define void @bar([8 x i8]* nocapture readonly %arg_ptr) #0 { > entrypoint: > %0 = bitcast [8 x

----- Original Message ----- > Thanks for the alternatives! > > I am trying the 'extracting sub-function' approach. However, it seems > I > can't get the 'subfunction' to pass the verifier. This is my > subfunction: > > define void @main_extern([8 x i8]* %arg_ptr) { > entrypoint: > %0 = getelementptr [8 x i8]* %arg_ptr, i32 0 > %1 =

Verifying function running passes ... LV: Checking a loop in "bar" LV: Found a loop: L0 LV: Found an induction variable. LV: We need to do 0 pointer comparisons. LV: Checking memory dependencies LV: Bad stride - Not an AddRecExpr pointer %13 = getelementptr float* %arg2, i32 %1 SCEV: ((4 * (sext i32 {(256 + %arg0),+,1}<nw><%L0> to i64)) + %arg2) LV: Src Scev: {((4 * (sext

Frank, It looks like the loop vectorizer is unable to tell that the two stores in your code never overlap. This is probably because of the sign-extend in your code. Can you extend the indices to 64bit ? Thanks, Nadav On Oct 28, 2013, at 1:38 PM, Frank Winter <fwinter at jlab.org> wrote: > Verifying function > running passes ... > LV: Checking a loop in "bar" > LV:

Hi, I am new to MemorySSA and wanted to understand its capabilities. Hence I wrote the following program (test.c): int N; void test(int *restrict a, int *restrict b, int *restrict c, int *restrict d, int *restrict e) { int i; for (i = 0; i < N; i = i + 5) { a[i] = b[i] + c[i]; } for (i = 0; i < N - 5; i = i + 5) { e[i] = a[i] * d[i]; } } I compiled this program using

On Tue, Dec 19, 2017 at 9:10 AM, Siddharth Bhat via llvm-dev < llvm-dev at lists.llvm.org> wrote: > I could be entirely wrong, but from my understanding of memorySSA, each > def defines an "abstract heap state" which has the coarsest possible > definition - any write will be modelled as a "new heap state". > This is true for def-def relationships, but

Hi Arnold, adding '-debug-only=loop-vectorize' to the command gives: LV: Checking a loop in "bar" LV: Found a loop: L0 LV: Found an induction variable. LV: Found an unidentified write ptr: %7 = load float** %6 LV: Found an unidentified read ptr: %10 = load float** %9 LV: Found an unidentified read ptr: %13 = load float** %12 LV: We need to do 2 pointer comparisons. LV: We

----- Original Message ----- > Hi Arnold, > > adding '-debug-only=loop-vectorize' to the command gives: > > LV: Checking a loop in "bar" > LV: Found a loop: L0 > LV: Found an induction variable. > LV: Found an unidentified write ptr: %7 = load float** %6 > LV: Found an unidentified read ptr: %10 = load float** %9 > LV: Found an unidentified

Hi Hal! I am using the 'x86_64' target. Below the complete module dump and here the command line: opt -march=x64-64 -loop-vectorize -debug-only=loop-vectorize -S test.ll Frank ; ModuleID = 'test.ll' target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-f128:128:128-v64:64:64-v128:12

>>> LV: The Widest type: 32 bits. >>> LV: The Widest register is: 32 bits. Yep, we don’t pick up the right TTI. Try -march=x86-64 (or leave it out) you already have this info in the triple. Then it should work (does for me with your example below). On Oct 26, 2013, at 2:16 PM, Frank Winter <fwinter at jlab.org> wrote: > Hi Hal! > > I am using the

----- Original Message ----- > >>> LV: The Widest type: 32 bits. > >>> LV: The Widest register is: 32 bits. > > Yep, we don’t pick up the right TTI. > > Try -march=x86-64 (or leave it out) you already have this info in the > triple. > > Then it should work (does for me with your example below). That may depend on what CPU is picks by default; Frank,

I would need this to work when calling the vectorizer through the function pass manager. Unfortunately I am having the same problem there: LV: The Widest type: 32 bits. LV: The Widest register is: 32 bits. It's not picking the target information, although I tried with and without the target triple in the module. Any idea what could be wrong? Frank On 26/10/13 15:54, Hal Finkel wrote:

Hi Frank, On Oct 26, 2013, at 6:29 PM, Frank Winter <fwinter at jlab.org> wrote: > I would need this to work when calling the vectorizer through > the function pass manager. Unfortunately I am having the same > problem there: I am not sure which function pass manager you are referring here. I assume you create your own (you are not using opt but configure your own pass

Hi Arnold, thanks for the detailed setup. Still, I haven't figured out the right thing to do. I would need only the native target since all generated code will execute on the JIT execution machine (right now, the old JIT interface). There is no need for other targets. Maybe it would be good to ask specific questions: How do I get the triple for the native target? How do I setup the

I changed the input C to using a 64 bit type for the loop index (this eliminates 'sext' instructions in the IR) Here the IR produced with clang -O0 define float @foo(i64 %start, i64 %end, float* %A) #0 { entry: %start.addr = alloca i64, align 8 %end.addr = alloca i64, align 8 %A.addr = alloca float*, align 8 %sum = alloca [4 x float], align 16 %i = alloca i64, align 8

I am trying my luck on this global reduction kernel: float foo( int start , int end , float * A ) { float sum[4] = {0.,0.,0.,0.}; for (int i = start ; i < end ; ++i ) { for (int q = 0 ; q < 4 ; ++q ) sum[q] += A[i*4+q]; } return sum[0]+sum[1]+sum[2]+sum[3]; } LV: Checking a loop in "foo" LV: Found a loop: for.cond1 LV: Found an induction variable. LV: We

Hi Nadav, Arnold, I managed to find some time to work on the pointer reduction, and I got a patch that can make "canVectorize()" pass. Basically what I do is to teach AddReductionVar() about pointers, saying they don't really have an exit instructions, and that (maybe) the final store is a good candidate (is it?). This makes it recognize the writes and reads, but then