[lld][RISCV] Avoid second map lookup in mergeArch. NFC

[topperc]

Instead of using find and then an inserting into the map, we can use insert and fix up the version using the iterator if the insert fails.

[llvmbot]

@llvm/pr-subscribers-lld

@llvm/pr-subscribers-lld-elf

Author: Craig Topper (topperc)

Changes

Instead of using find and then an inserting into the map, we can use insert and fix up the version using the iterator if the insert fails.

---

Full diff: https://github.com/llvm/llvm-project/pull/84687.diff

1 Files Affected:

• (modified) lld/ELF/Arch/RISCV.cpp (+4-4)

diff --git a/lld/ELF/Arch/RISCV.cpp b/lld/ELF/Arch/RISCV.cpp
index 4798c86f7d1b61..20de1b9b7bde96 100644
--- a/lld/ELF/Arch/RISCV.cpp
+++ b/lld/ELF/Arch/RISCV.cpp
@@ -1074,12 +1074,12 @@ static void mergeArch(RISCVISAInfo::OrderedExtensionMap &mergedExts,
     mergedXlen = info.getXLen();
   } else {
     for (const auto &ext : info.getExtensions()) {
-      if (auto it = mergedExts.find(ext.first); it != mergedExts.end()) {
-        if (std::tie(it->second.Major, it->second.Minor) >=
+      auto p = mergedExts.insert(ext);
+      if (!p.second) {
+        if (std::tie(p.first->second.Major, p.first->second.Minor) <
             std::tie(ext.second.Major, ext.second.Minor))
-          continue;
+          p.first->second = ext.second;
       }
-      mergedExts[ext.first] = ext.second;
     }
   }
 }