[NFC][Utils] Eliminate DISubprogram set from BuildDebugInfoMDMap

[artempyanykh]

Stacked PRs:

• [Coro] Use DebugInfoCache to speed up cloning in CoroSplitPass #118630
• [Analysis] Add DebugInfoCache analysis #118629
• [Coro] Prebuild a module-level debug info set and share it between all coroutine clones #118628
• [Utils] Identity map module-level debug info on first use in CloneFunction* #118627
• ->[NFC][Utils] Eliminate DISubprogram set from BuildDebugInfoMDMap #118625
• [NFC][Utils] Extract CloneFunctionBodyInto from CloneFunctionInto #118624
• [NFC][Utils] Extract CloneFunctionMetadataInto from CloneFunctionInto #118623

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[NFC][Utils] Eliminate DISubprogram set from BuildDebugInfoMDMap

Summary:
Previously, we'd add all SPs distinct from the cloned one into a set.
Then when cloning a local scope we'd check if it's from one of those
'distinct' SPs by checking if it's in the set. We don't need to do that.
We can just check against the cloned SP directly and drop the set.

Test Plan:
ninja check-llvm-unit check-llvm

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Artem Pianykh (artempyanykh)

Changes

[NFC][Utils] Eliminate DISubprogram set from BuildDebugInfoMDMap

Summary:
Previously, we'd add all SPs distinct from the cloned one into a set.
Then when cloning a local scope we'd check if it's from one of those
'distinct' SPs by checking if it's in the set. We don't need to do that.
We can just check against the cloned SP directly and drop the set.

Test Plan:
ninja check-llvm-unit check-llvm

---

Full diff: https://github.com/llvm/llvm-project/pull/118625.diff

1 Files Affected:

• (modified) llvm/lib/Transforms/Utils/CloneFunction.cpp (+2-5)

diff --git a/llvm/lib/Transforms/Utils/CloneFunction.cpp b/llvm/lib/Transforms/Utils/CloneFunction.cpp
index 1f4cdec333a2c2..5bc90bc7ae23da 100644
--- a/llvm/lib/Transforms/Utils/CloneFunction.cpp
+++ b/llvm/lib/Transforms/Utils/CloneFunction.cpp
@@ -171,18 +171,15 @@ bool llvm::BuildDebugInfoMDMap(MDMapT &MD, CloneFunctionChangeType Changes,
     };
 
     // Avoid cloning types, compile units, and (other) subprograms.
-    SmallPtrSet<const DISubprogram *, 16> MappedToSelfSPs;
     for (DISubprogram *ISP : DIFinder.subprograms()) {
-      if (ISP != SPClonedWithinModule) {
+      if (ISP != SPClonedWithinModule)
         mapToSelfIfNew(ISP);
-        MappedToSelfSPs.insert(ISP);
-      }
     }
 
     // If a subprogram isn't going to be cloned skip its lexical blocks as well.
     for (DIScope *S : DIFinder.scopes()) {
       auto *LScope = dyn_cast<DILocalScope>(S);
-      if (LScope && MappedToSelfSPs.count(LScope->getSubprogram()))
+      if (LScope && LScope->getSubprogram() != SPClonedWithinModule)
         mapToSelfIfNew(S);
     }