Ahmed Bougacha d78960d142 [X86] Reuse EFLAGS and form LOCKed ops when only user is SETCC. ... Re-apply r265450 which caused PR27245 and was reverted in r265559 because of a wrong generalization: the fetch_and_add->add_and_fetch combine only works in specific, but pretty common, cases: (icmp slt x, 0) -> (icmp sle (add x, 1), 0) (icmp sge x, 0) -> (icmp sgt (add x, 1), 0) (icmp sle x, 0) -> (icmp slt (sub x, 1), 0) (icmp sgt x, 0) -> (icmp sge (sub x, 1), 0) Original Message: We only generate LOCKed versions of add/sub when the result is unused. It often happens that the result is used, but only by a comparison. We can optimize those out by reusing EFLAGS, which lets us use the proper instructions, instead of having to fallback to LXADD. Instead of doing this as an MI peephole (as we do for the other non-LOCKed (really, non-MR) forms), do it in ISel. It becomes quite tricky later. This also makes it eventually possible to stop expanding and/or/xor if the only user is an icmp (also see D18141). This uses the LOCK ISD opcodes added by r262244. Differential Revision: http://reviews.llvm.org/D17633 llvm-svn: 265636		2016-04-07 02:07:10 +00:00
..
Analysis	AMDGPU: Add a shader calling convention	2016-04-06 19:40:20 +00:00
Assembler	AsmParser: Don't crash on unresolved !tbaa	2016-04-06 02:06:40 +00:00
Bindings	[OCaml] Reinstate data_layout	2016-04-01 07:54:24 +00:00
Bitcode	Bitcode: Try to emit metadata in function blocks	2016-04-02 15:22:57 +00:00
BugPoint
CodeGen	[X86] Reuse EFLAGS and form LOCKed ops when only user is SETCC.	2016-04-07 02:07:10 +00:00
DebugInfo	Add missing emissionKind flags to the DICompileUnits of several old testcases.	2016-04-01 22:18:43 +00:00
Examples
ExecutionEngine
Feature
FileCheck
Instrumentation	[sancov] enabling coverage edge pruning by default.	2016-04-06 23:24:37 +00:00
Integer
JitListener	testcase gardening: update the emissionKind enum to the new syntax. (NFC)	2016-04-01 00:16:49 +00:00
LibDriver
Linker	testcase gardening: update the emissionKind enum to the new syntax. (NFC)	2016-04-01 00:16:49 +00:00
LTO	[LoopVectorize] Don't unconditionally print vectorization diagnostics	2016-04-01 00:34:39 +00:00
MC	[AMDGPU] AsmParser: disable DPP for unsupported instructions. New dpp tests. Fix v_nop_dpp.	2016-04-06 13:29:59 +00:00
Object	Thread Expected<...> up from createMachOObjectFile() to allow llvm-objdump to produce a real error message	2016-04-06 22:14:09 +00:00
Other
SymbolRewriter
TableGen
ThinLTO/X86	ThinLTO: special handling for LinkOnce functions	2016-04-01 21:53:50 +00:00
tools	Thread Expected<...> up from createMachOObjectFile() to allow llvm-objdump to produce a real error message	2016-04-06 22:14:09 +00:00
Transforms	[LoopUnroll] Fix the way we update DT after complete unrolling.	2016-04-06 21:47:12 +00:00
Unit
Verifier	[IRVerifier] Don't crash on invalid DIFile inside DISubprogram.	2016-04-06 18:46:39 +00:00
YAMLParser
.clang-format
CMakeLists.txt
lit.cfg	test: Always treat .mir files as tests even outside of CodeGen/MIR	2016-04-04 21:23:44 +00:00
lit.site.cfg.in
TestRunner.sh