[clang] Add regalloc PBQP for all targets in clang

clang/test/CodeGen/PBQP-regalloc-all-targets.c

@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 %s -triple x86_64 -O2 \
+// RUN:  -mllvm -regalloc=pbqp \
+// RUN:  -mllvm --print-changed -S |& FileCheck %s
+// CHECK: IR Dump After PBQP Register Allocator (regallocpbqp) on foo
+
+extern int foo(int a, int b) {
+  return a + b;
+}

llvm/include/llvm/InitializePasses.h

@@ -272,6 +272,7 @@ LLVM_ABI void initializeReassociateLegacyPassPass(PassRegistry &);
 LLVM_ABI void
 initializeRegAllocEvictionAdvisorAnalysisLegacyPass(PassRegistry &);
 LLVM_ABI void initializeRegAllocFastPass(PassRegistry &);
+LLVM_ABI void initializeRegAllocPBQPPass(PassRegistry &);
 LLVM_ABI void
 initializeRegAllocPriorityAdvisorAnalysisLegacyPass(PassRegistry &);
 LLVM_ABI void initializeRegAllocScoringPass(PassRegistry &);

llvm/lib/CodeGen/CodeGen.cpp

@@ -117,6 +117,7 @@ void llvm::initializeCodeGen(PassRegistry &Registry) {
   initializeRAGreedyLegacyPass(Registry);
   initializeReachingDefInfoWrapperPassPass(Registry);
   initializeRegAllocFastPass(Registry);
+  initializeRegAllocPBQPPass(Registry);
   initializeRegUsageInfoCollectorLegacyPass(Registry);
   initializeRegUsageInfoPropagationLegacyPass(Registry);
   initializeRegisterCoalescerLegacyPass(Registry);

llvm/lib/CodeGen/RegAllocPBQP.cpp

@@ -946,6 +946,9 @@ void PBQP::RegAlloc::PBQPRAGraph::printDot(raw_ostream &OS) const {
   OS << "}\n";
 }
 
+INITIALIZE_PASS(RegAllocPBQP, "regallocpbqp", "PBQP Register Allocator", false,
+                false)
+
 FunctionPass *llvm::createPBQPRegisterAllocator(char *customPassID) {
   return new RegAllocPBQP(customPassID);
 }