I noticed high and low in there so those code snippets look like 32 bit code, at least to me.

Is that even a fair comparison given the arm and x86 versions used as examples of "better" were 64 bit?

If we're really comparing 32 and 64 and complaining that 32 bit uses more instructions than 64, perhaps we should dig out the 4 bit processors and really sharpen the pitchforks. Alternatively, we could simply not. Comparing apples to oranges doesn't really help.

From the article:

Let's look at some examples of how Risc V underperforms.

First, addition of a double-word integer with carry-out:

add t0, a4, a6 // add low words

sltu t6, t0, a4 // compute carry-out from low add

add t1, a5, a7 // add hi words

sltu t2, t1, a5 // compute carry-out from high add

add t4, t1, t6 // add carry to low result

sltu t3, t4, t1 // compute carry out from the carry add

add t6, t2, t3 // combine carries

Same for 64-bit arm:

adds x12, x6, x10

adcs x13, x7, x11

Same for 64-bit x86:

add %r8, %rax

adc %r9, %rdx