[BOLT][NFC] Simplify analyzeIndirectBranch

[aaupov]

Simplify mutually exclusive sanity checks in analyzeIndirectBranch,
where an UNKNOWN IndirectBranchType is to be returned. Reduces confusion
and code duplication when adding a new IndirectBranchType (to be added
in #91667).

Test Plan: NFC

[llvmbot]

@llvm/pr-subscribers-bolt

Author: Amir Ayupov (aaupov)

Changes

Simplify mutually exclusive sanity checks in analyzeIndirectBranch,
where an UNKNOWN IndirectBranchType is to be returned. Reduces confusion
and code duplication when adding a new IndirectBranchType (to be added
in a follow-up diff).

Test Plan: NFC

---

Full diff: https://github.com/llvm/llvm-project/pull/91662.diff

1 Files Affected:

• (modified) bolt/lib/Target/X86/X86MCPlusBuilder.cpp (+9-7)

diff --git a/bolt/lib/Target/X86/X86MCPlusBuilder.cpp b/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
index e7cabdabce90..86e7d4dfaed8 100644
--- a/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
+++ b/bolt/lib/Target/X86/X86MCPlusBuilder.cpp
@@ -2115,13 +2115,15 @@ class X86MCPlusBuilder : public MCPlusBuilder {
       return IndirectBranchType::POSSIBLE_FIXED_BRANCH;
     }
 
-    if (Type == IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE &&
-        (MO->ScaleImm != 1 || MO->BaseRegNum != RIPRegister))
-      return IndirectBranchType::UNKNOWN;
-
-    if (Type != IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE &&
-        MO->ScaleImm != PtrSize)
-      return IndirectBranchType::UNKNOWN;
+    switch (Type) {
+    case IndirectBranchType::POSSIBLE_PIC_JUMP_TABLE:
+      if (MO->ScaleImm != 1 || MO->BaseRegNum != RIPRegister)
+        return IndirectBranchType::UNKNOWN;
+      break;
+    default:
+      if (MO->ScaleImm != PtrSize)
+        return IndirectBranchType::UNKNOWN;
+    }
 
     MemLocInstrOut = MemLocInstr;
 

[rafaelauler]

LG