[llvm] [GlobalMerge][NFC] Fix inaccurate comments (PR #124136)

[Michael Maitland via llvm-commits]

https://github.com/michaelmaitland updated https://github.com/llvm/llvm-project/pull/124136

>From 8924adb254828edf1be5d2260e72ad179783410c Mon Sep 17 00:00:00 2001
From: Michael Maitland <michaeltmaitland at gmail.com>
Date: Thu, 23 Jan 2025 07:53:08 -0800
Subject: [PATCH] [GlobalMerge][NFC] Fix inaccurate comment

I was studying the code here and realized that the comments were talking about
grouping by basic blocks when the code was grouping by Function. Fix the
comments so they reflect what the code is actually doing.
---
 llvm/lib/CodeGen/GlobalMerge.cpp | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/llvm/lib/CodeGen/GlobalMerge.cpp b/llvm/lib/CodeGen/GlobalMerge.cpp
index 48d4d7848d84a7..9d4547df046d46 100644
--- a/llvm/lib/CodeGen/GlobalMerge.cpp
+++ b/llvm/lib/CodeGen/GlobalMerge.cpp
@@ -378,7 +378,7 @@ bool GlobalMergeImpl::doMerge(SmallVectorImpl<GlobalVariable *> &Globals,
 
         size_t UGSIdx = GlobalUsesByFunction[ParentFn];
 
-        // If this is the first global the basic block uses, map it to the set
+        // If this is the first global the function uses, map it to the set
         // consisting of this global only.
         if (!UGSIdx) {
           // If that set doesn't exist yet, create it.
@@ -393,7 +393,8 @@ bool GlobalMergeImpl::doMerge(SmallVectorImpl<GlobalVariable *> &Globals,
           continue;
         }
 
-        // If we already encountered this BB, just increment the counter.
+        // If we already encountered a use of this global in this function, just
+        // increment the counter.
         if (UsedGlobalSets[UGSIdx].Globals.test(GI)) {
           ++UsedGlobalSets[UGSIdx].UsageCount;
           continue;
@@ -423,7 +424,7 @@ bool GlobalMergeImpl::doMerge(SmallVectorImpl<GlobalVariable *> &Globals,
   }
 
   // Now we found a bunch of sets of globals used together.  We accumulated
-  // the number of times we encountered the sets (i.e., the number of blocks
+  // the number of times we encountered the sets (i.e., the number of functions
   // that use that exact set of globals).
   //
   // Multiply that by the size of the set to give us a crude profitability