Steve White wrote:
I was under the misconception that each of these SSE operatons
was meant to be accomplished in a single clock cycle (although I knew there
are various other issues.)
Current CPU architectures permit an SSE scalar or parallel multiply and
add instruction to be issued on eac
On Sun, Jan 24, 2010 at 10:32 PM, Steve White wrote:
> Richard,
>
> Could you provide us with a good reference for the latencies and other
> speed issues of SSE operations? What I've found is scattered and hard
> to compare.
>
> Frankly, I was under the misconception that each of these SSE operat
Richard,
Could you provide us with a good reference for the latencies and other
speed issues of SSE operations? What I've found is scattered and hard
to compare.
Frankly, I was under the misconception that each of these SSE operatons
was meant to be accomplished in a single clock cycle (although
On Sat, Jan 23, 2010 at 6:33 PM, Steve White wrote:
> Hi, Andrew!
>
> Thanks for the suggestion, but it didn't make any difference for me.
> Neither the speed nor the assembler was significantly altered.
>
> Which version of gcc did you use? Mine is 4.4.1.
>
> I threw everything at it:
> g
Hi, Andrew!
Thanks for the suggestion, but it didn't make any difference for me.
Neither the speed nor the assembler was significantly altered.
Which version of gcc did you use? Mine is 4.4.1.
I threw everything at it:
gcc -std=c99 -Wall -pedantic -O3 -ffast-math -mmmx -msse -msse2
-mf
On Sat, Jan 23, 2010 at 5:47 PM, Steve White wrote:
> Hi,
>
> I recently revised some speed tests of basic CPU operations.
> There were a few surprises, but one was that, a test of double-precision
> divide was a factor of ten slower when compiled with gcc than with the
> Intel compiler icc.
>
> T
On Sat, Jan 23, 2010 at 8:47 AM, Steve White wrote:
> gcc has this (gcc -std=c99 -O3 -msse2 -mfpmath=sse -lm -S dt.c)
> icc has this (icc -Wall -w2 -fast -c dt.c)
icc's -fast is equivalent to gcc's -ffast-math option which you did
not supply so you comparing apples to oranges.
Note supplying -ff
