Bionic/libm: fast neon pow() for small x,y.

Add a fast neon version of pow() suitable for relatively small
positive x and y (between 0 and 4).  Run the standard
implementation in all other cases.  Gives approximately 60%
performance improvement to AnTuTu FPU scores

Change-Id: I97e0712daeb2740764b26a44be0caaa39c481453
Bionic/libm: Prefer branches and VFP ABI.

For internal functions set gcc attribute "aapcs-vfp" for ARM
and use -fno-if-conversion to prefer branches over predicated
instructions (improves performance on architectures with good
branch prediction).

Change-Id: I8424e0e82a19d35e7e3b6e3e122dcdecdd5426fd
Bionic/libm: add assembly versions of sin/cos.

Add assembly versions of sin/cos with integrated remainder pi/2
calculation.  Directly extracted from binary libm.so compiled with
__ieee754_rem_pio2 calls inlined.

Change-Id: Ia093f420e58e794635e3a5f09e8236ae7601f1f6
Bionic/libm: Pow optimizations and bug fixes.

Use VFP calling convention for pow_neon handoff function by default.
Fix register usage collision between two different polynomial
coefficients in pow_neon.  Remove conditional execution in pow_neon
and replace with branching.

Change-Id: I76095f4a006e2fb01a53943b66fd69bfa1fd3033
Bionic/libm: Add precision-correct de-serialize sin/cos.

Modify sin/cos to improve performance while retaining bit-for-bit
accuracy with existing algorithm.

Change-Id: Iaba2dd731cd015732744705dad8bddb713b43067
libm: optimistic pow calling.

Call optimized pow optimistically and revert to full range
implementation if we detect an out-of-range input.

Change-Id: I6f3aa734adbf99484b7ff70736ef83a41e5815b8
libm: sqrt and sqrtf via ARM vsqrt instruction

Optimized sqrt and sqrtf for arm by using hardware
opcode for sqrt rather than generic slow portable
code.

Change-Id: I84694159577aef6418710548085d8149c45e0e3f
Bionic/libm: Remove extra vmov from sin/cos.

Move integer representations of x bits on the integer side rather
than moving them to and from the FP registers.

Change-Id: I1895db385c9616cdae9ab6403f392dfbae292adc
Bionic/libm: enable optimized math functions on more QCOM targets.

allow more QCOM targets to use optimized math functions.

Change-Id: I76ee1bf951ae1c8397fef3af6e9937ed8cad9b62
libm: Fix multiple inclusion warning

Change-Id: Ifa732ec52fb582c34512cd1d09d918199ae7395e
linker: restore prelink support

Prelink support is required to load old vendor binary blobs
on many devices properly

This commit partially reverts 4688279db5dcc4004941e7f133c4a1c3617d842c

Change-Id: Iee5325e048daee78e8dcaa47c87454b908c89b4e
libc: Add Scorpion-optimized memcpy and memset

 * Optimized routines from Qualcomm for msm8660 class SoCs
 * Enable with TARGET_CPU_VARIANT := scorpion

Change-Id: I01d0f22efba5a418ddd20fca0d0c570d855e0f6f
Bionic: Add AOSP master cortex optimizations

libc/arch-arm/bionic/memcpy.a9.S: memcpy from cortex-strings.

This memcpy code uses NEON/VFP to achieve very good performance
on ARMv7-A processors. It is specifically tuned for A15 but should
provide good performance on A9 also. It is equivalent to the code
in cortex-strings rev 116.

This patch is a follow up the existing gerrit change:

I7f6f77995f3ca903ad9c66d14261441667a2a935

But this version includes a tweak for performance on misaligned
buffers.

Change-Id: I285abac0068f8ae29a1cbf7862ea8590aadaf0a7
Signed-off-by: Will Newton <will.newton@linaro.org>

libc/arch-arm/bionic/memcpy.a9.S: memcpy from cortex-strings.

This memcpy code uses NEON/VFP to achieve very good performance
on ARMv7-A processors. It is specifically tuned for A15 but should
provide good performance on A9 also. It is equivalent to the code
in cortex-strings rev 116.

This patch is a follow up the existing gerrit change:

I7f6f77995f3ca903ad9c66d14261441667a2a935

This version includes a tweak for performance on misaligned
buffers and splits the header comment into license and
documentation sections.

Change-Id: Ibd2e23c8d8e01357ba0247be1d05192de3ceba69
Signed-off-by: Will Newton <will.newton@linaro.org>

Add new optimized strlen for arm.

This optimized version is primarily targeted at cortex-a15.

Tested on all nexus devices using the system/extras/libc_test strlen test.
Tested alignments from 1 to 32 that are powers of 2.
Tested that strlen does not cross page boundaries at all alignments.

Speed improvements listed below:

cortex-a15
- Sizes >= 32 bytes, ~75% improvement.
- Sizes >= 1024 bytes, ~250% improvement.

cortex-a9
- Sizes >= 32 bytes, ~75% improvement.
- Sizes >= 1024 bytes, ~85% improvement.

krait
- Sizes >= 32 bytes, ~95% improvement.
- Sizes >= 1024 bytes, ~160% improvement.

Merge from internal master.

(cherry-picked from 2fc071797743b88a9a47427d46baed7c7b24f4d2)

Change-Id: I1ceceb4e745fd68e9d946f96d1d42e0cdaff6ccf

Conflicts:
	libc/arch-arm/generic/generic.mk
	libc/arch-arm/krait/krait.mk

libgcc_compat: Introduce __aeabi_lasr for cortex-a9 and higher

This is needed when passing -mcpu=cortex-a9 or higher on a modern
toolchain for prebuilt library compatibility

Change-Id: I73eb2393377914ae26216a8c2828ad973d1c1225
libc: Use the fast strlen on Scorpion too

Change-Id: I9ba50a469de27269adc008c2a96767830ad6b70b
libc: arch-arm: strlen: Illegal ARM entries fixed

Spacing between brackets is a illegal ARM entry

PS1 - Inital patch
PS2 - update description and rebase

Signed-off-by: Paul Beeler <sparksco@gmail.com>

Change-Id: I52d7e95a8afb8b26f55fe0bc01853a15a95e90c2
libc: Update to latest cortexa15 memcpy code.

This uses the new code original submitted as memcpy.a15.S as
the base. However, the old code handled unaligned src/dst better
so that was spliced in. I optimized the original unaligned code by
removing a few unnecessary instructions. I optimized the a15 code by
rewriting the pre and post code. I also modified the main loop to add
a pld so that larger copies would not stall waiting for memory.

Test cases for the new memcpy:

- Copy all sized values from 0 to 1024 bytes, using whatever alignment
  is returned by malloc.
For each alignment case described below, the test copied from 0 to 128
bytes.
- Src and dst pointers are both aligned to the same value, starting
  at one going through every power of two up to and including 128.
- Src aligned to double word boundary, dst aligned to word boundary.
- Src aligned to word boundary, dst aligned to double word boundary.
- Src aligned to 16 bit boundary, dst aligned to word boundary.
- Src aligned to word boundary, dst aligned to 16 byte boundary.
- Src aligned to word boundary, dst aligned to 1 byte from a word
  boundary.
- Src aligned to word boundary, dst aligned to 2 bytes from a word
  boundary.
- Src aligned to word boundary, dst aligned to 3 bytes from a word
  boundary.
- Src aligned to 1 byte from a word boundary, dst aligned to a word
  boundary.
- Src aligned to 2 bytes from a word boundary, dst aligned to a word
  boundary.
- Src aligned to 3 bytes from a word boundary, dst aligned to a word
  boundary.

Cases to verify the unaligned source code properly aligns to a 16 bit
boundary.
- Src aligned to 1 byte from a 128 bit boundary, dst aligned to
  4 + 128 bit boundary.
- Src aligned to 1 byte from a 128 bit boundary, dst aligned to
  8 + 128 bit boundary.
- Src aligned to 1 byte from a 128 bit boundary, dst aligned to
  12 + 128 bit boundary.
- Src aligned to 1 byte from a 128 bit boundary, dst aligned to
  16 + 128 bit boundary.

In all cases, a two byte fencepost was placed at the end of the
destination to verify that only the requested number of bytes were copied.

Bug: 8005082

Merge from internal master.

(cherry-picked from commit 21ede92d794969f22cacbdb9f557818f1c5712b5)

Change-Id: Ief70c9e6dc8c6473ae245b6570b2c266fed9618c

Add missing branch in memcpy.S dst aligned case.

Merge from internal master.

(cherry-picked from commit 6ffaa931c362602a2b606a610c92326a425a876e)

Change-Id: Ifdcf01fd122866cf0d4c5b5f7a997803561d7889

Rewrite memset for cortexa15 to use strd.

Merge from internal master.

(cherry-picked from commit 7ffad9c120054eedebd5f56f8bed01144e93eafa)

Change-Id: Ia67f2a545399f4fa37b63d5634a3565e4f5482f9
libc: Optimize strcat/strcpy, small tweaks to strlen

Create one version of strcat/strcpy/strlen for cortex-a15/krait/scorpion and another
version for cortex-a9.

Tested with the libc_test strcat/strcpy/strlen tests.
Including new tests that verify that the src for strcat/strcpy do not
overread across page boundaries.

NOTE: The handling of unaligned strcpy (same code in strcat) could probably
be optimized further such that the src is read 64 bits at a time instead of
the partial reads occurring now.

strlen improves slightly since it was recently optimized.

Performance improvements for strcpy and strcat (using an empty dest string):

cortex-a9
- Small copies vary from about 5% to 20% as the size gets above 10 bytes.
- Copies >= 1024, about a 60% improvement.
- Unaligned copies, from about 40% improvement.

cortex-a15
- Most small copies exhibit a 100% improvement, a few copies only
  improve by 20%.
- Copies >= 1024, about 150% improvement.
- Unaligned copies, about 100% improvement.

krait
- Most small copies vary widely, but on average 20% improvement, then
  the performance gets better, hitting about a 100% improvement when
  copies 64 bytes of data.
- Copies >= 1024, about 100% improvement.
- When coping MBs of data, about 50% improvement.
- Unaligned copies, about 90% improvement.

As strcat destination strings get larger in size:

cortex-a9
- about 40% improvement for small dst strings (>= 32).
- about 250% improvement for dst strings >= 1024.

cortex-a15
- about 200% improvement for small dst strings (>=32).
- about 250% improvement for dst strings >= 1024.

krait
- about 25% improvement for small dst strings (>=32).
- about 100% improvement for dst strings >=1024.

Merge from internal master.

(cherry-picked from d119b7b6f48fe507088cfb98bcafa99b320fd884)

Change-Id: I296463b251ef9fab004ee4dded2793feca5b547a

Conflicts:
	libc/Android.mk
	libc/arch-arm/generic/generic.mk
	libc/arch-arm/krait/krait.mk

Fix strcpy.c that should have been strcpy.S

Merge from internal master.

(cherry-picked from 1ce665416307628f4bcaced86faa64bdf9c489c3)

Conflicts:
	libc/arch-arm/generic/generic.mk

Change-Id: I376b831df42248baadde7202a30a68112f752ff7
Revert "Everyone has a TLS register."

This reverts commit 91a9925998f2b878f0245ce03aab22cc412a4d8b.

Conflicts:

	libc/Android.mk
	libc/private/bionic_tls.h

Change-Id: I1401ab19e3035c1ed132781f126aafc5149d66ae
ifdef fegetenv/fesetenv for neon (vmrs, vmsr)

Change-Id: I314e8ad9aabed04e70a148618ba1c83108bc6448
Fix assembler errors in generic arm strlen.c.

Tested using a static version of the strlen libc_test program
on a nexus7 that uses the generic code.

Merge from internal master.

(cherry-picked from d8d10a8994472e40d19301b7087806630877b4d5)

Change-Id: I88f7dc01dc5b5c3ac2d5580d92153bc1bc36c564