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Re: Should -msse3 enable fisttp?
- From: Evan Cheng <echeng at apple dot com>
- To: Evan Cheng <echeng at apple dot com>
- Cc: gcc at gcc dot gnu dot org, Uros Bizjak <uros dot bizjak at kss-loka dot si>
- Date: Mon, 3 Oct 2005 14:44:09 -0700
- Subject: Re: Should -msse3 enable fisttp?
- References: <179A6816-4A60-4FC6-B9AE-CC920FBBC16A@apple.com>
Hi Uros,
Since you are the one who enabled fisttp, I figure I should send this
email to you directly.
Let me know what you think. I kind of agree with your argument. But
for practical reasons I thinkg -msse3 should enable fisttp. Certainly
here in Apple, a few folks have been surprised by this.
Thanks,
Evan
Senior Compiler Engineer
Apple Computers
On Sep 29, 2005, at 1:48 PM, Evan Cheng wrote:
Hi,
I know this has been discussed in bug 18668. But I'd like to bring
it up again.
Currently, fisttp is only generated with -march=prescott. The
argument is fisttp is not a SSE instruction. While this is
technically true, it's likely to surprise the users. Intel, after
all, does lump fisttp in SSE3. AMD64 architecture programmer's
manual also explicitly state fisttp is a SSE3 instruction.
Please consider enabling fisttp with -msse3.
Thanks,
Evan