Magic-Mirror/llvm-capstone
1
0
Fork 0
mirror of https://github.com/capstone-engine/llvm-capstone.git synced 2025-01-22 17:03:32 +00:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

[Layout] Add a new option (NFC)

Browse Source 
Currently cost based loop rotation algo can only be turned on with
two conditions: the function has real profile data, and -precise-rotation-cost
flag is turned on. This is not convenient for developers to experiment
when profile is not available. Add a new option to force the new
rotation algorithm -force-precise-rotation-cost

llvm-svn: 269266
This commit is contained in:
Xinliang David Li 2016-05-12 02:04:41 +00:00
parent a61cb48dd2
commit f0ab6dfedc
1 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
llvm/lib/CodeGen/MachineBlockPlacement.cpp
View File

@ -99,6 +99,11 @@ static cl::opt<bool>
cl::desc("Model the cost of loop rotation more "
"precisely by using profile data."),
cl::init(false), cl::Hidden);
static cl::opt<bool>
ForcePreciseRotationCost("force-precise-rotation-cost",
cl::desc("Model the cost of loop rotation more "
"precisely by using profile data."),
cl::init(false), cl::Hidden);
static cl::opt<unsigned> MisfetchCost(
"misfetch-cost",
@ -1126,7 +1131,8 @@ void MachineBlockPlacement::buildLoopChains(MachineFunction &F,
// this loop by modeling costs more precisely which requires the profile data
// for better layout.
bool RotateLoopWithProfile =
PreciseRotationCost && F.getFunction()->getEntryCount();
ForcePreciseRotationCost ||
(PreciseRotationCost && F.getFunction()->getEntryCount());
// First check to see if there is an obviously preferable top block for the
// loop. This will default to the header, but may end up as one of the