This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]
Other format:	[Raw text]

[PATCH, i386]: Split shifts with useless masked count operand to a normal shift

From: Uros Bizjak <ubizjak at gmail dot com>
To: "gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>
Date: Tue, 16 Aug 2016 20:29:58 +0200
Subject: [PATCH, i386]: Split shifts with useless masked count operand to a normal shift
Authentication-results: sourceware.org; auth=none

x86 can do masking on the count operand by itself. Instead of
inventing new insn, just split the combined pattern to a normal shift
insn.

2016-08-16  Uros Bizjak  <ubizjak@gmail.com>

    * config/i386/i386.md (*ashl<mode>3_mask): Rewrite define_insn
    pattern as define_insn_and_split.  Split insn before reload to
    ashl<mode>3_1.
    (*<shift_insn><mode>3_mask): Ditto.  Split insn before reload to
    <shift_insn><mode>3_1.
    (*<rotate_insn><mode>3_mask): Ditto.  Split insn before reload to
    <rotate_insn><mode>3_1.

Bootstrapped and regression tested on x86_64-linux-gnu {,-m32}.
Committed to mainline.

Uros.

Attachment: p.diff.txt
Description: Text document

Index Nav:	[Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav:	[Date Prev] [Date Next]	[Thread Prev] [Thread Next]