+static bool
+combineInstructionsOverFunction(Function &F, InstCombineWorklist &Worklist,
+ AliasAnalysis *AA, AssumptionCache &AC,
+ TargetLibraryInfo &TLI, DominatorTree &DT,
+ LoopInfo *LI = nullptr) {
+ auto &DL = F.getParent()->getDataLayout();
+
+ /// Builder - This is an IRBuilder that automatically inserts new
+ /// instructions into the worklist when they are created.
+ IRBuilder<true, TargetFolder, InstCombineIRInserter> Builder(
+ F.getContext(), TargetFolder(DL), InstCombineIRInserter(Worklist, &AC));
+
+ // Lower dbg.declare intrinsics otherwise their value may be clobbered
+ // by instcombiner.
+ bool DbgDeclaresChanged = LowerDbgDeclare(F);
+
+ // Iterate while there is work to do.
+ int Iteration = 0;
+ for (;;) {
+ ++Iteration;
+ DEBUG(dbgs() << "\n\nINSTCOMBINE ITERATION #" << Iteration << " on "
+ << F.getName() << "\n");
+
+ bool Changed = false;
+ if (prepareICWorklistFromFunction(F, DL, &TLI, Worklist))
+ Changed = true;
+
+ InstCombiner IC(Worklist, &Builder, F.optForMinSize(),
+ AA, &AC, &TLI, &DT, DL, LI);
+ if (IC.run())
+ Changed = true;
+
+ if (!Changed)
+ break;
+ }
+
+ return DbgDeclaresChanged || Iteration > 1;
+}
+
+PreservedAnalyses InstCombinePass::run(Function &F,
+ AnalysisManager<Function> *AM) {
+ auto &AC = AM->getResult<AssumptionAnalysis>(F);
+ auto &DT = AM->getResult<DominatorTreeAnalysis>(F);
+ auto &TLI = AM->getResult<TargetLibraryAnalysis>(F);
+
+ auto *LI = AM->getCachedResult<LoopAnalysis>(F);
+
+ // FIXME: The AliasAnalysis is not yet supported in the new pass manager
+ if (!combineInstructionsOverFunction(F, Worklist, nullptr, AC, TLI, DT, LI))
+ // No changes, all analyses are preserved.
+ return PreservedAnalyses::all();
+
+ // Mark all the analyses that instcombine updates as preserved.
+ // FIXME: Need a way to preserve CFG analyses here!
+ PreservedAnalyses PA;
+ PA.preserve<DominatorTreeAnalysis>();
+ return PA;
+}
+