Kevin Qin dbaeb6e7cb Use a loop to simplify the runtime unrolling prologue. ... Runtime unrolling will create a prologue to execute the extra iterations which is can't divided by the unroll factor. It generates an if-then-else sequence to jump into a factor -1 times unrolled loop body, like extraiters = tripcount % loopfactor if (extraiters == 0) jump Loop: if (extraiters == loopfactor) jump L1 if (extraiters == loopfactor-1) jump L2 ... L1: LoopBody; L2: LoopBody; ... if tripcount < loopfactor jump End Loop: ... End: It means if the unroll factor is 4, the loop body will be 7 times unrolled, 3 are in loop prologue, and 4 are in the loop. This commit is to use a loop to execute the extra iterations in prologue, like extraiters = tripcount % loopfactor if (extraiters == 0) jump Loop: else jump Prol Prol: LoopBody; extraiters -= 1 // Omitted if unroll factor is 2. if (extraiters != 0) jump Prol: // Omitted if unroll factor is 2. if (tripcount < loopfactor) jump End Loop: ... End: Then when unroll factor is 4, the loop body will be copied by only 5 times, 1 in the prologue loop, 4 in the original loop. And if the unroll factor is 2, new loop won't be created, just as the original solution. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218604 91177308-0d34-0410-b5e6-96231b3b80d8		2014-09-29 11:15:00 +00:00
..
Analysis
Assembler
Bindings
Bitcode
BugPoint
CodeGen	[x86] Make the new vector shuffle lowering lower blends as VSELECT	2014-09-29 09:57:07 +00:00
DebugInfo
ExecutionEngine
Feature
FileCheck
Instrumentation
Integer
JitListener
Linker
LTO
MC	[Thumb2] ldrexd and strexd are not defined on v7M	2014-09-29 10:57:29 +00:00
Object
Other
TableGen
tools
Transforms	Use a loop to simplify the runtime unrolling prologue.	2014-09-29 11:15:00 +00:00
Unit
Verifier
YAMLParser
.clang-format
CMakeLists.txt
lit.cfg
lit.site.cfg.in
Makefile
Makefile.tests
TestRunner.sh