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Re: [Bug target/14552] compiled trivial vector intrinsic code is inefficient

From: Andrew Pinski <pinskia at gmail dot com>
To: "gcc-bugzilla at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>
Cc: "gcc-bugs at gcc dot gnu dot org" <gcc-bugs at gcc dot gnu dot org>
Date: Wed, 19 Mar 2008 17:22:23 -0700
Subject: Re: [Bug target/14552] compiled trivial vector intrinsic code is inefficient
References: <bug-14552-4523@http.gcc.gnu.org/bugzilla/> <20080320000408.20267.qmail@sourceware.org>

See pr 33790.

Sent from my iPhone

On Mar 19, 2008, at 17:04, "ubizjak at gmail dot com" <gcc-bugzilla@gcc.gnu.org > wrote:

------- Comment #30 from ubizjak at gmail dot com 2008-03-20 00:04 ------- (In reply to comment #28)
(In reply to comment #27)
The store is not useless. Reload from "_w" is how gcc handles double stores nowadays and is not mmx specific. It looks that some pass forgot to check where the value came from.
Do you happen to know if there are two different modes at work here? If so there are patches which fix this up in DSE and post-reload CSE.
Yes, from comment #24 (slightly changed):
typedef short mmxw  __attribute__ ((vector_size (8)));
typedef int   mmxdw __attribute__ ((vector_size (8)));
mmxdw dw;
mmxw w;
so, we have V4HI and V2SI.

--

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=14552

References:
- [Bug target/14552] compiled trivial vector intrinsic code is inefficient
  - From: ubizjak at gmail dot com

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