hi,
when i do the diff
// Compute diff int32x4_t diff1_4 = vabsq_s32(vsubq_s32(A, B));
I got 4 result. One for each test (A1,B1)(A2,B2)(A3,B3) and (A4,B4)
And than i have to do the comparaison
uint32x4_t mask1_4 = vcltq_s32(diff1_4, X);
So in "uint32x4_t mask1_4" i got the comparaison for each test, so 4 résult.
the answer on post "SIMD help for exemple" was to use
if (vmaxvq_u32(mask1_4) > 0) { ... }
I thinks my sentence was confuse in the previous post. I wrote
" if (mask1_4[0] > 0 && mask1_4[1] > 0) and if (mask1_4[2] > 0 && mask1_4[3] > 0) "
but it is not if( mask1_4[0] > 0 && mask1_4[1] > 0 && mask1_4[2] > 0 && mask1_4[3] > 0) )
i need to do 2 test
if (mask1_4[0] > 0 && mask1_4[1] > 0){
process data1
}
if (mask1_4[2] > 0 && mask1_4[3] > 0){
process data2
I think that vmaxvq_u32(mask1_4) will check all the comparaison. like
if( mask1_4[0] > 0 && mask1_4[1] > 0 && mask1_4[2] > 0 && mask1_4[3] > 0 )
PS: i think i should have post it in the old post
hterrolle said:it look like vmaxvq_u32 is for 128bits,"uint32x4_t", long and not 64bits,"uint32x2_t". I tried to find the correct function but without result.
hterrolle said:I need an vmaxvq_u32 or vminvq_u32 how work with uint32x2_t.
NEON intrinsics are relatively regular in terms of naming convention, the "q" versions are 128-bit quad-word versions, the non-q versions are 64-bit double work versions.
So vmaxvq_u32() is the 128-bit version, and vmaxv_u32() is the 64-bit version.
hterrolle said:why if ( mask1_4[0] > 0 && mask1_4[1] > 0) work with a -1 value. It does look at the sign ?
mask1_4 is an unsigned uint32 type, so 4294967295 not -1. NEON compares just return a vector with all bits set if true, or all bits clear for false, which is useful for use in logical bitwise mask operations.
i check it pomorow.
and thanks again. I spend 6 hours on neon today. I am full. ;))