Getting max value in a __m128i vector with SSE?

Question

I have just started using SSE and I am confused how to get the maximum integer value (max) of a __m128i. For instance:

__m128i t =         


        

Answer 1

According to this page, there is no horizontal max, and you need to test the elements vertically:

movhlps xmm1,xmm0         ; Move top two floats to lower part of xmm1
maxps   xmm0,xmm1         ; Get maximum of the two sets of floats
pshufd  xmm1,xmm0,$55     ; Move second float to lower part of xmm1
maxps   xmm0,xmm1         ; Get minimum of the two remaining floats

Conversely, getting the minimum:

movhlps xmm1,xmm0
minps   xmm0,xmm1
pshufd  xmm1,xmm0,$55
minps   xmm0,xmm1