[llvm] [DWARF][NFC] Remove unused 'Reads' param from checkCFADiff and checkRegDiff (PR #174941)

[Konrad Kleine via llvm-commits]

https://github.com/kwk updated https://github.com/llvm/llvm-project/pull/174941

>From 105f82367f4107cd5881d83648d0860a70b524e1 Mon Sep 17 00:00:00 2001
From: Konrad Kleine <kkleine at redhat.com>
Date: Thu, 8 Jan 2026 11:24:30 +0100
Subject: [PATCH] [DWARF][NFC] Remove unused 'Reads' param from checkCFADiff
 and checkRegDiff

and the variable that was used as the argument.
---
 .../llvm/DWARFCFIChecker/DWARFCFIAnalysis.h        |  2 --
 llvm/lib/DWARFCFIChecker/DWARFCFIAnalysis.cpp      | 14 +++-----------
 2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/llvm/include/llvm/DWARFCFIChecker/DWARFCFIAnalysis.h b/llvm/include/llvm/DWARFCFIChecker/DWARFCFIAnalysis.h
index be1025e691561..0620ca9fbc147 100644
--- a/llvm/include/llvm/DWARFCFIChecker/DWARFCFIAnalysis.h
+++ b/llvm/include/llvm/DWARFCFIChecker/DWARFCFIAnalysis.h
@@ -85,12 +85,10 @@ class DWARFCFIAnalysis {
   void checkRegDiff(const MCInst &Inst, DWARFRegNum Reg,
                     const dwarf::UnwindRow &PrevRow,
                     const dwarf::UnwindRow &NextRow,
-                    const SmallSet<DWARFRegNum, 4> &Reads,
                     const SmallSet<DWARFRegNum, 4> &Writes);
 
   void checkCFADiff(const MCInst &Inst, const dwarf::UnwindRow &PrevRow,
                     const dwarf::UnwindRow &NextRow,
-                    const SmallSet<DWARFRegNum, 4> &Reads,
                     const SmallSet<DWARFRegNum, 4> &Writes);
 
 private:
diff --git a/llvm/lib/DWARFCFIChecker/DWARFCFIAnalysis.cpp b/llvm/lib/DWARFCFIChecker/DWARFCFIAnalysis.cpp
index 269e4dc603429..9074a406d9b0d 100644
--- a/llvm/lib/DWARFCFIChecker/DWARFCFIAnalysis.cpp
+++ b/llvm/lib/DWARFCFIChecker/DWARFCFIAnalysis.cpp
@@ -134,10 +134,7 @@ void DWARFCFIAnalysis::update(const MCInst &Inst,
   for (auto &&Directive : Directives)
     State.update(Directive);
 
-  SmallSet<DWARFRegNum, 4> Writes, Reads;
-  for (unsigned I = 0; I < MCInstInfo.NumImplicitUses; I++)
-    Reads.insert(MCRI->getDwarfRegNum(
-        getSuperReg(MCRI, MCInstInfo.implicit_uses()[I]), IsEH));
+  SmallSet<DWARFRegNum, 4> Writes;
   for (unsigned I = 0; I < MCInstInfo.NumImplicitDefs; I++)
     Writes.insert(MCRI->getDwarfRegNum(
         getSuperReg(MCRI, MCInstInfo.implicit_defs()[I]), IsEH));
@@ -148,9 +145,6 @@ void DWARFCFIAnalysis::update(const MCInst &Inst,
       if (I < MCInstInfo.getNumDefs())
         Writes.insert(
             MCRI->getDwarfRegNum(getSuperReg(MCRI, Op.getReg()), IsEH));
-      else if (Op.getReg())
-        Reads.insert(
-            MCRI->getDwarfRegNum(getSuperReg(MCRI, Op.getReg()), IsEH));
     }
   }
 
@@ -158,19 +152,18 @@ void DWARFCFIAnalysis::update(const MCInst &Inst,
   assert(MaybeNextRow && "previous row existed, so should the current row");
   auto NextRow = *MaybeNextRow;
 
-  checkCFADiff(Inst, PrevRow, NextRow, Reads, Writes);
+  checkCFADiff(Inst, PrevRow, NextRow, Writes);
 
   for (auto LLVMReg : getTrackingRegs(MCRI)) {
     DWARFRegNum Reg = MCRI->getDwarfRegNum(LLVMReg, IsEH);
 
-    checkRegDiff(Inst, Reg, PrevRow, NextRow, Reads, Writes);
+    checkRegDiff(Inst, Reg, PrevRow, NextRow, Writes);
   }
 }
 
 void DWARFCFIAnalysis::checkRegDiff(const MCInst &Inst, DWARFRegNum Reg,
                                     const dwarf::UnwindRow &PrevRow,
                                     const dwarf::UnwindRow &NextRow,
-                                    const SmallSet<DWARFRegNum, 4> &Reads,
                                     const SmallSet<DWARFRegNum, 4> &Writes) {
   auto MaybePrevLoc = PrevRow.getRegisterLocations().getRegisterLocation(Reg);
   auto MaybeNextLoc = NextRow.getRegisterLocations().getRegisterLocation(Reg);
@@ -260,7 +253,6 @@ void DWARFCFIAnalysis::checkRegDiff(const MCInst &Inst, DWARFRegNum Reg,
 void DWARFCFIAnalysis::checkCFADiff(const MCInst &Inst,
                                     const dwarf::UnwindRow &PrevRow,
                                     const dwarf::UnwindRow &NextRow,
-                                    const SmallSet<DWARFRegNum, 4> &Reads,
                                     const SmallSet<DWARFRegNum, 4> &Writes) {
 
   auto MaybePrevCFA = getCFARegOffsetInfo(PrevRow);