Cong Hou 20b64d0452 Allow X86::COND_NE_OR_P and X86::COND_NP_OR_E to be reversed. ... Currently, AnalyzeBranch() fails non-equality comparison between floating points on X86 (see https://llvm.org/bugs/show_bug.cgi?id=23875). This is because this function can modify the branch by reversing the conditional jump and removing unconditional jump if there is a proper fall-through. However, in the case of non-equality comparison between floating points, this can turn the branch "unanalyzable". Consider the following case: jne.BB1 jp.BB1 jmp.BB2 .BB1: ... .BB2: ... AnalyzeBranch() will reverse "jp .BB1" to "jnp .BB2" and then "jmp .BB2" will be removed: jne.BB1 jnp.BB2 .BB1: ... .BB2: ... However, AnalyzeBranch() cannot analyze this branch anymore as there are two conditional jumps with different targets. This may disable some optimizations like block-placement: in this case the fall-through behavior is enforced even if the fall-through block is very cold, which is suboptimal. Actually this optimization is also done in block-placement pass, which means we can remove this optimization from AnalyzeBranch(). However, currently X86::COND_NE_OR_P and X86::COND_NP_OR_E are not reversible: there is no defined negation conditions for them. In order to reverse them, this patch defines two new CondCode X86::COND_E_AND_NP and X86::COND_P_AND_NE. It also defines how to synthesize instructions for them. Here only the second conditional jump is reversed. This is valid as we only need them to do this "unconditional jump removal" optimization. Differential Revision: http://reviews.llvm.org/D11393 llvm-svn: 258847		2016-01-26 20:08:01 +00:00
..
Analysis	[DemandedBits] Fix computation of demanded bits for ICmps	2016-01-25 14:49:36 +00:00
Assembler	Fix constant folding of constant vector GEPs with undef or null as pointer argument.	2016-01-19 16:34:31 +00:00
Bindings	Deprecate a few C APIs.	2015-12-18 23:46:42 +00:00
Bitcode	[WinEH] Verify unwind edges against EH pad tree	2016-01-10 04:28:38 +00:00
BugPoint
CodeGen	Allow X86::COND_NE_OR_P and X86::COND_NP_OR_E to be reversed.	2016-01-26 20:08:01 +00:00
DebugInfo	Followup to 258750; update more tests to use .p2align .	2016-01-26 00:35:07 +00:00
Examples
ExecutionEngine	[RuntimeDyld][AArch64] Add support for the MachO ARM64_RELOC_SUBTRACTOR reloc.	2016-01-21 21:59:50 +00:00
Feature	MachineScheduler: Honor optnone functions in the pre-ra scheduler.	2016-01-20 22:38:25 +00:00
FileCheck
Instrumentation	[sanitizer] [msan] Fix origin store of array types	2016-01-11 19:55:27 +00:00
Integer
JitListener	Fix several accidental DOS line endings in source files	2016-01-03 17:22:03 +00:00
LibDriver
Linker	[ThinLTO] Find all needed metadata when linking metadata as postpass	2016-01-25 22:04:56 +00:00
LTO	[LTO] Restore original linkage of externals prior to splitting	2016-01-18 23:24:54 +00:00
MC	Followup to 258750; update all MC tests to use .p2align .	2016-01-26 00:27:59 +00:00
Object	Update the comments for the macho-invalid-zero-ncmds test and fix	2016-01-26 18:20:49 +00:00
Other	Recommit r256952 "Filtering IR printing for print-after-all/print-before-all"	2016-01-06 22:55:03 +00:00
SymbolRewriter
TableGen	[GlobalISel] Add a generic machine opcode for ADD.	2016-01-20 19:14:55 +00:00
tools	[llvm-readobj] Add -elf-section-groups option	2016-01-26 19:46:39 +00:00
Transforms	Reassociate: Reprocess RedoInsts after each inst	2016-01-26 18:42:36 +00:00
Unit
Verifier	Add a "gc-transition" operand bundle	2016-01-20 19:50:25 +00:00
YAMLParser
.clang-format
CMakeLists.txt	Introduce sanstats tool and llvm::CreateSanitizerStatReport function.	2016-01-16 00:31:11 +00:00
lit.cfg	Introduce sanstats tool and llvm::CreateSanitizerStatReport function.	2016-01-16 00:31:11 +00:00
lit.site.cfg.in	Make WinCOFFObjectWriter.cpp's timestamp writing not use ENABLE_TIMESTAMPS	2016-01-06 19:05:19 +00:00
Makefile	check-llvm: Tweak the feature "timestamps" for autoconf.	2015-12-21 08:46:12 +00:00
Makefile.tests
TestRunner.sh