[llvm] abea3b2 - [RDF] Skip over NoRegister. NFCI. (#80672)

[via llvm-commits]

Author: Jay Foad
Date: 2024-02-05T14:15:55Z
New Revision: abea3b27991dd73cad251f623a2a8f25a3e786ff

URL: https://github.com/llvm/llvm-project/commit/abea3b27991dd73cad251f623a2a8f25a3e786ff
DIFF: https://github.com/llvm/llvm-project/commit/abea3b27991dd73cad251f623a2a8f25a3e786ff.diff

LOG: [RDF] Skip over NoRegister. NFCI. (#80672)

This just avoids useless work of adding NoRegister to BaseSet, for
consistency with other places that iterate over all physical registers.

Added: 
    

Modified: 
    llvm/lib/CodeGen/RDFGraph.cpp

Removed: 
    


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diff  --git a/llvm/lib/CodeGen/RDFGraph.cpp b/llvm/lib/CodeGen/RDFGraph.cpp
index 6b2e69da76f23..6276a4722e3f0 100644
--- a/llvm/lib/CodeGen/RDFGraph.cpp
+++ b/llvm/lib/CodeGen/RDFGraph.cpp
@@ -870,7 +870,7 @@ void DataFlowGraph::build(const Config &config) {
     std::set<RegisterId> BaseSet;
     if (BuildCfg.Classes.empty()) {
       // Insert every register.
-      for (unsigned R = 0, E = getPRI().getTRI().getNumRegs(); R != E; ++R)
+      for (unsigned R = 1, E = getPRI().getTRI().getNumRegs(); R != E; ++R)
         BaseSet.insert(R);
     } else {
       for (const TargetRegisterClass *RC : BuildCfg.Classes) {