Robin Morisset 2b1874cbd4 [Power] Improve the expansion of atomic loads/stores ... Summary: Atomic loads and store of up to the native size (32 bits, or 64 for PPC64) can be lowered to a simple load or store instruction (as the synchronization is already handled by AtomicExpand, and the atomicity is guaranteed thanks to the alignment requirements of atomic accesses). This is exactly what this patch does. Previously, these were implemented by complex load-linked/store-conditional loops.. an obvious performance problem. For example, this patch turns ``` define void @store_i8_unordered(i8* %mem) { store atomic i8 42, i8* %mem unordered, align 1 ret void } ``` from ``` _store_i8_unordered: ; @store_i8_unordered ; BB#0: rlwinm r2, r3, 3, 27, 28 li r4, 42 xori r5, r2, 24 rlwinm r2, r3, 0, 0, 29 li r3, 255 slw r4, r4, r5 slw r3, r3, r5 and r4, r4, r3 LBB4_1: ; =>This Inner Loop Header: Depth=1 lwarx r5, 0, r2 andc r5, r5, r3 or r5, r4, r5 stwcx. r5, 0, r2 bne cr0, LBB4_1 ; BB#2: blr ``` into ``` _store_i8_unordered: ; @store_i8_unordered ; BB#0: li r2, 42 stb r2, 0(r3) blr ``` which looks like a pretty clear win to me. Test Plan: fixed the tests + new test for indexed accesses + make check-all Reviewers: jfb, wschmidt, hfinkel Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D5587 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218922 91177308-0d34-0410-b5e6-96231b3b80d8		2014-10-02 22:27:07 +00:00
..
Analysis	Move the complex address expression out of DIVariable and into an extra	2014-10-01 18:55:02 +00:00
Assembler	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
Bindings	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
Bitcode	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
BugPoint	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
CodeGen	[Power] Improve the expansion of atomic loads/stores	2014-10-02 22:27:07 +00:00
DebugInfo	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
ExecutionEngine
Feature	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
FileCheck
Instrumentation	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
Integer
JitListener	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
Linker	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
LTO	LTO: Add missing target triple from r218784	2014-10-01 18:49:58 +00:00
MC	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
Object
Other
TableGen	[AVX512] Added intrinsics for VPCMPEQB and VPCMPEQW.	2014-09-30 11:32:22 +00:00
tools	llvm-readobj: print COFF imported symbols	2014-10-02 22:05:29 +00:00
Transforms	Revert "DI: Fold constant arguments into a single MDString"	2014-10-02 22:15:31 +00:00
Unit
Verifier
YAMLParser
.clang-format
CMakeLists.txt
lit.cfg	pass environment when invoking llvm-config from lit.cfg	2014-09-24 18:37:48 +00:00
lit.site.cfg.in
Makefile
Makefile.tests
TestRunner.sh