Reenable NonTrivial Loop Unswitch

Author: vchuravy

src/codegen.cpp

@@ -9073,9 +9073,6 @@ extern "C" void jl_init_llvm(void)
     clopt = llvmopts.lookup("unswitch-threshold");
     if (clopt->getNumOccurrences() == 0)
         cl::ProvidePositionalOption(clopt, "100", 1);
-    clopt = llvmopts.lookup("enable-unswitch-cost-multiplier");
-    if (clopt->getNumOccurrences() == 0)
-        cl::ProvidePositionalOption(clopt, "false", 1);
 #endif
     // if the patch adding this option has been applied, lower its limit to provide
     // better DAGCombiner performance.

src/pipeline.cpp

@@ -385,7 +385,7 @@ static void buildFullPipeline(ModulePassManager &MPM, PassBuilder *PB, Optimizat
 #endif
             LPM2.addPass(LICMPass(LICMOptions()));
             JULIA_PASS(LPM2.addPass(JuliaLICMPass()));
-            LPM2.addPass(SimpleLoopUnswitchPass(false, true));
+            LPM2.addPass(SimpleLoopUnswitchPass(/*NonTrivial*/true, true));
             LPM2.addPass(LICMPass(LICMOptions()));
             JULIA_PASS(LPM2.addPass(JuliaLICMPass()));
             //LICM needs MemorySSA now, so we must use it