[AMDGPU] Avoid repeated hash lookups (NFC)

[kazutakahirata]

No description provided.

[llvmbot]

@llvm/pr-subscribers-backend-amdgpu

Author: Kazu Hirata (kazutakahirata)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/127445.diff

1 Files Affected:

• (modified) llvm/lib/Target/AMDGPU/R600OptimizeVectorRegisters.cpp (+3-2)

diff --git a/llvm/lib/Target/AMDGPU/R600OptimizeVectorRegisters.cpp b/llvm/lib/Target/AMDGPU/R600OptimizeVectorRegisters.cpp
index ac11526da0919..17f724c3173d9 100644
--- a/llvm/lib/Target/AMDGPU/R600OptimizeVectorRegisters.cpp
+++ b/llvm/lib/Target/AMDGPU/R600OptimizeVectorRegisters.cpp
@@ -270,9 +270,10 @@ bool R600VectorRegMerger::tryMergeUsingCommonSlot(RegSeqInfo &RSI,
       MOE = RSI.Instr->operands_end(); MOp != MOE; ++MOp) {
     if (!MOp->isReg())
       continue;
-    if (PreviousRegSeqByReg[MOp->getReg()].empty())
+    auto &Insts = PreviousRegSeqByReg[MOp->getReg()];
+    if (Insts.empty())
       continue;
-    for (MachineInstr *MI : PreviousRegSeqByReg[MOp->getReg()]) {
+    for (MachineInstr *MI : Insts) {
       CompatibleRSI = PreviousRegSeq[MI];
       if (RSI == CompatibleRSI)
         continue;