Ahmed Bougacha 16a661561f [ARM] Emit clrex in the expanded cmpxchg fail block. ...

ARM counterpart to r248291:

In the comparison failure block of a cmpxchg expansion, the initial
ldrex/ldxr will not be followed by a matching strex/stxr.
On ARM/AArch64, this unnecessarily ties up the execution monitor,
which might have a negative performance impact on some uarchs.

Instead, release the monitor in the failure block.
The clrex instruction was designed for this: use it.

Also see ARMARM v8-A B2.10.2:
"Exclusive access instructions and Shareable memory locations".

Differential Revision: http://reviews.llvm.org/D13033

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@248294 91177308-0d34-0410-b5e6-96231b3b80d8

2015-09-22 17:22:58 +00:00

..

Analysis

Untabify.

2015-09-22 11:15:07 +00:00

AsmParser

auto and range-for-ify some things to make changing container types a bit easier in the (possibly near) future

2015-09-21 21:07:50 +00:00

Bitcode

Silencing a -Wsign-compare warning; NFC.

2015-09-18 13:31:42 +00:00

CodeGen

[AArch64] Emit clrex in the expanded cmpxchg fail block.

2015-09-22 17:21:44 +00:00

DebugInfo

Use makeArrayRef or None to avoid unnecessarily mentioning the ArrayRef type extra times. NFC

2015-09-21 05:32:41 +00:00

ExecutionEngine

Remove roundingMode argument in APFloat::mod

2015-09-21 19:29:25 +00:00

Fuzzer

[libFuzzer] perform fewer crossover operations compared to plain mutations

2015-09-11 00:20:58 +00:00

IR

Remove roundingMode argument in APFloat::mod

2015-09-21 19:29:25 +00:00

IRReader

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LibDriver

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LineEditor

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Linker

[opaque pointer types] Switch a few cases of getElementType over, since I had them lying around anyway

2015-09-14 20:29:26 +00:00

LTO

Reapply "LTO: Disable extra verify runs in release builds"

2015-09-15 23:05:59 +00:00

MC

Untabify.

2015-09-22 11:15:07 +00:00

Object

Prune trailing whitespaces.

2015-09-22 11:19:03 +00:00

Option

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Passes

[PM] Port SROA to the new pass manager.

2015-09-12 09:09:14 +00:00

ProfileData

GCC AutoFDO profile reader - Initial support.

2015-09-17 00:17:24 +00:00

Support

Untabify.

2015-09-22 11:15:07 +00:00

TableGen

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Target

[ARM] Emit clrex in the expanded cmpxchg fail block.

2015-09-22 17:22:58 +00:00

Transforms

Prune trailing whitespaces.

2015-09-22 11:19:03 +00:00

CMakeLists.txt

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LLVMBuild.txt

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Makefile

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