[polly] [polly] Replace SmallSet with SmallPtrSet (NFC) (PR #154367)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/154367

This patch replaces SmallSet<T *, N> with SmallPtrSet<T *, N>.  Note
that SmallSet.h "redirects" SmallSet to SmallPtrSet for pointer
element types:

  template <typename PointeeType, unsigned N>
  class SmallSet<PointeeType*, N> : public SmallPtrSet<PointeeType*, N> {};

We only have 10 instances that rely on this "redirection". Since the
redirection doesn't improve readability, this patch replaces SmallSet
with SmallPtrSet for pointer element types.

I'm planning to remove the redirection eventually.


>From 9da7f901833bde87f5479f2ca4b6c35ce60aace4 Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Mon, 18 Aug 2025 23:17:27 -0700
Subject: [PATCH] [polly] Replace SmallSet with SmallPtrSet (NFC)

This patch replaces SmallSet<T *, N> with SmallPtrSet<T *, N>.  Note
that SmallSet.h "redirects" SmallSet to SmallPtrSet for pointer
element types:

  template <typename PointeeType, unsigned N>
  class SmallSet<PointeeType*, N> : public SmallPtrSet<PointeeType*, N> {};

We only have 10 instances that rely on this "redirection". Since the
redirection doesn't improve readability, this patch replaces SmallSet
with SmallPtrSet for pointer element types.

I'm planning to remove the redirection eventually.
---
 polly/lib/Analysis/ScopBuilder.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/polly/lib/Analysis/ScopBuilder.cpp b/polly/lib/Analysis/ScopBuilder.cpp
index c0babb85f5c46..67a4c43455809 100644
--- a/polly/lib/Analysis/ScopBuilder.cpp
+++ b/polly/lib/Analysis/ScopBuilder.cpp
@@ -689,7 +689,7 @@ isl::set ScopBuilder::getPredecessorDomainConstraints(BasicBlock *BB,
 
   // Set of regions of which the entry block domain has been propagated to BB.
   // all predecessors inside any of the regions can be skipped.
-  SmallSet<Region *, 8> PropagatedRegions;
+  SmallPtrSet<Region *, 8> PropagatedRegions;
 
   for (auto *PredBB : predecessors(BB)) {
     // Skip backedges.