6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-24 08:29:39 +00:00
Code Issues Projects Releases Wiki Activity

LoopVectorizer: Don't count the induction variable multiple times

Browse Source 
When estimating register pressure, don't count the induction variable mulitple
times. It is unlikely to be unrolled. This is currently disabled and hidden
behind a flag ("enable-ind-var-reg-heur").

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200371 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Arnold Schwaighofer 2014-01-29 04:36:12 +00:00
parent c86f56a506
commit 8dc253e97b
1 changed files with 9 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
lib/Transforms/Vectorize/LoopVectorize.cpp
View File

@ -188,6 +188,10 @@ static cl::opt<unsigned> NumberOfStoresToPredicate(
"vectorize-num-stores-pred", cl::init(0), cl::Hidden,
cl::desc("Max number of stores to be predicated behind an if."));
static cl::opt<bool> EnableIndVarRegisterHeur(
"enable-ind-var-reg-heur", cl::init(false), cl::Hidden,
cl::desc("Count the induction variable only once when unrolling"));
static cl::opt<bool> EnableCondStoresVectorization(
"enable-cond-stores-vec", cl::init(false), cl::Hidden,
cl::desc("Enable if predication of stores during vectorization."));
@ -5155,6 +5159,11 @@ LoopVectorizationCostModel::selectUnrollFactor(bool OptForSize,
unsigned UF = PowerOf2Floor((TargetNumRegisters - R.LoopInvariantRegs) /
R.MaxLocalUsers);
// Don't count the induction variable as unrolled.
if (EnableIndVarRegisterHeur)
UF = PowerOf2Floor((TargetNumRegisters - R.LoopInvariantRegs - 1) /
std::max(1U, (R.MaxLocalUsers - 1)));
// Clamp the unroll factor ranges to reasonable factors.
unsigned MaxUnrollSize = TTI.getMaximumUnrollFactor();