Commit Graph

6 Commits

Author SHA1 Message Date
Elliott Hughes
3cf53d1a78 Fixes for the ARM-specific bswap_16, bswap_32, and bswap_64.
1. Make the feature test work by excluding known-deficient processors, so
we don't have to maintain a complete list of all the processors that support
REV and REV16.

2. Don't abuse 'register' to get an effect similar to GCC's +l constraint,
but which was unnecessarily restrictive.

3. Fix __swap64md so _x isn't clobbered, breaking 64-bit swaps.

4. Make <byteswap.h> (which declars bswap_16 and friends) use <endian.h>
rather than <sys/endian.h>, so we get the machine-dependent implementations.

Change-Id: I6a38fad7a9fbe394aff141489617eb3883e1e944
2010-09-26 11:26:53 -07:00
Jim Huang
aa35095517 Use ARMv6 instruction for handling byte order
ARMv6 ISA has several instructions to handle data in different byte order.
For endian conversion (byte swapping) of single data words, it might be a
good idea to use the REV/REV16 instruction simply.

Change-Id: Ic4a5ed6254e082763e54aa70d428f59a0088636e
2010-08-31 14:51:44 +08:00
Jim Huang
a172709259 bionic: Rename _ARM_HAVE_LDREX_STREX to __ARM_HAVE_LDREX_STREX for consistency
The patch follows the naming manner in existing macros with prefix
__ARM_HAVE.

Change-Id: I6763ce2bf3ee85fd1da112c719543061d8d19bf4
2010-08-09 05:35:11 +08:00
vinay harugop
76ec6891e2 ARM architecture reference manuals for ARMv6 & ARMv7 state that the use of 'swp' instruction is deprecated
ARMv6 onwards. These architectures provide the load-linked, store-conditional pair of ldrex/strex whose use
is recommended in place of 'swp'. Also, the description of the 'swp' instruction in the ARMv6 reference
manual states that the swap operation does not include any memory barrier guarantees.This fix attempts to
address these issues by providing an atomic swap implementation using ldrex/strex under _ARM_HAVE_LDREX_STREX
macro.  This Fix is verified on ST Ericsson's U8500 platform and Submitted on behalf of a third-party:
Surinder-pal SINGH from STMicroelectronics.
2009-09-09 21:01:46 +05:30
The Android Open Source Project
4e468ed2eb Code drop from //branches/cupcake/...@124589 2008-12-17 18:03:48 -08:00
The Android Open Source Project
a27d2baa0c Initial Contribution 2008-10-21 07:00:00 -07:00