[PATCH] D114886: [LoopOptWG][LoopUnroll] Disable loop unroll when user explicitly asks for unroll-and-jam

[Zaara Syeda via Phabricator via llvm-commits]

This revision was landed with ongoing or failed builds.
This revision was automatically updated to reflect the committed changes.
Closed by commit rGdd245bab9fbb: [LoopUnroll] Disable loop unroll when user explicitly asks for unroll-and-jam (authored by syzaara).

Changed prior to commit:
  https://reviews.llvm.org/D114886?vs=391083&id=394279#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D114886/new/

https://reviews.llvm.org/D114886

Files:
  llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp


Index: llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
===================================================================
--- llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
+++ llvm/lib/Transforms/Scalar/LoopUnrollPass.cpp
@@ -1136,6 +1136,31 @@
   TransformationMode TM = hasUnrollTransformation(L);
   if (TM & TM_Disable)
     return LoopUnrollResult::Unmodified;
+
+  // If this loop isn't forced to be unrolled, avoid unrolling it when the
+  // parent loop has an explicit unroll-and-jam pragma. This is to prevent
+  // automatic unrolling from interfering with the user requested
+  // transformation.
+  Loop *ParentL = L->getParentLoop();
+  if (ParentL != NULL &&
+      hasUnrollAndJamTransformation(ParentL) == TM_ForcedByUser &&
+      hasUnrollTransformation(L) != TM_ForcedByUser) {
+    LLVM_DEBUG(dbgs() << "Not unrolling loop since parent loop has"
+                      << " llvm.loop.unroll_and_jam.\n");
+    return LoopUnrollResult::Unmodified;
+  }
+
+  // If this loop isn't forced to be unrolled, avoid unrolling it when the
+  // loop has an explicit unroll-and-jam pragma. This is to prevent automatic
+  // unrolling from interfering with the user requested transformation.
+  if (hasUnrollAndJamTransformation(L) == TM_ForcedByUser &&
+      hasUnrollTransformation(L) != TM_ForcedByUser) {
+    LLVM_DEBUG(
+        dbgs()
+        << "  Not unrolling loop since it has llvm.loop.unroll_and_jam.\n");
+    return LoopUnrollResult::Unmodified;
+  }
+
   if (!L->isLoopSimplifyForm()) {
     LLVM_DEBUG(
         dbgs() << "  Not unrolling loop which is not in loop-simplify form.\n");


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D114886.394279.patch
Type: text/x-patch
Size: 1614 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20211214/42d47ff1/attachment.bin>