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[ARM] Use UBFX for some and-immediate operations

From: Richard Earnshaw <rearnsha at arm dot com>
To: gcc-patches at gcc dot gnu dot org
Date: Thu, 02 Aug 2012 17:24:56 +0100
Subject: [ARM] Use UBFX for some and-immediate operations

This patch adds the ability to spot and exploit the UBFX instruction
(bit-field extract) to perform AND operations with an immediate which is
2^N - 1.  On some benchmarks this can lead to a significant win over the
existing behaviour on Cortex-A15.

Tested on arm-eabi with some additional testing on arm-linux-gnueabi
platforms.

R.

2012-08-02  Richard Earnshaw  <rearnsha@arm.com>

	* arm.c (arm_gen_constant): Use UBFX for some AND operations when
	available.

Attachment: bfield.patch
Description: Text document

Follow-Ups:
- Re: [ARM] Use UBFX for some and-immediate operations
  - From: Richard Henderson

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