[LV] Remove unused configuration option

[nilanjana87]

Recent set of changes (Ref: #67725) in loop interleaving algorithm removed the loop trip count threshold for allowing interleaving. Therefore configuration option interleave-small-loop-scalar-reduction option is no longer needed.

[llvmbot]

@llvm/pr-subscribers-backend-powerpc

@llvm/pr-subscribers-llvm-transforms

Author: Nilanjana Basu (nilanjana87)

Changes

Recent set of changes (Ref: #67725) in loop interleaving algorithm removed the loop trip count threshold for allowing interleaving. Therefore interleave-small-loop-scalar-reduction option is no longer useful.

---

Full diff: https://github.com/llvm/llvm-project/pull/82955.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/Vectorize/LoopVectorize.cpp (+1-8)

diff --git a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
index 373ea751d568ae..b7ae932677bbe3 100644
--- a/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
+++ b/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp
@@ -315,12 +315,6 @@ static cl::opt<bool> EnableLoadStoreRuntimeInterleave(
     cl::desc(
         "Enable runtime interleaving until load/store ports are saturated"));
 
-/// Interleave small loops with scalar reductions.
-static cl::opt<bool> InterleaveSmallLoopScalarReduction(
-    "interleave-small-loop-scalar-reduction", cl::init(false), cl::Hidden,
-    cl::desc("Enable interleaving for loops with small iteration counts that "
-             "contain scalar reductions to expose ILP."));
-
 /// The number of stores in a loop that are allowed to need predication.
 static cl::opt<unsigned> NumberOfStoresToPredicate(
     "vectorize-num-stores-pred", cl::init(1), cl::Hidden,
@@ -5477,8 +5471,7 @@ LoopVectorizationCostModel::selectInterleaveCount(ElementCount VF,
 
     // If there are scalar reductions and TTI has enabled aggressive
     // interleaving for reductions, we will interleave to expose ILP.
-    if (InterleaveSmallLoopScalarReduction && VF.isScalar() &&
-        AggressivelyInterleaveReductions) {
+    if (VF.isScalar() && AggressivelyInterleaveReductions) {
       LLVM_DEBUG(dbgs() << "LV: Interleaving to expose ILP.\n");
       // Interleave no less than SmallIC but not as aggressive as the normal IC
       // to satisfy the rare situation when resources are too limited.

[fhahn]

LGTM, thanks.

Please try to shorten the commit title to be more concise, as per https://llvm.org/docs/DeveloperPolicy.html#commit-messages

The title should be concise. Because all commits are emailed to the list with the first line as the subject, long titles are frowned upon. Short titles also look better in git log.

[nilanjana87]

Updated a test that used this option to fix a build bot error. Squashed commits, rebased & force-pushed.