Merge pull request #44798 from JuliaLang/kf/bugpoint

Make julia bootstrap bugpointable

Author: Keno

src/aotcompile.cpp

@@ -605,7 +605,8 @@ void addMachinePasses(legacy::PassManagerBase *PM, TargetMachine *TM, int optlev
 // this defines the set of optimization passes defined for Julia at various optimization levels.
 // it assumes that the TLI and TTI wrapper passes have already been added.
 void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level,
-                           bool lower_intrinsics, bool dump_native)
+                           bool lower_intrinsics, bool dump_native,
+                           bool external_use)
 {
     // Note: LLVM 12 disabled the hoisting of common instruction
     //       before loop vectorization (https://reviews.llvm.org/D84108).
@@ -654,7 +655,7 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level,
         }
         PM->add(createLowerSimdLoopPass()); // Annotate loop marked with "loopinfo" as LLVM parallel loop
         if (dump_native) {
-            PM->add(createMultiVersioningPass());
+            PM->add(createMultiVersioningPass(external_use));
             PM->add(createCPUFeaturesPass());
             // minimal clean-up to get rid of CPU feature checks
             if (opt_level == 1) {
@@ -696,7 +697,7 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level,
     PM->add(createInstructionCombiningPass());
     PM->add(createCFGSimplificationPass(simplifyCFGOptions));
     if (dump_native)
-        PM->add(createMultiVersioningPass());
+        PM->add(createMultiVersioningPass(external_use));
     PM->add(createCPUFeaturesPass());
     PM->add(createSROAPass());
     PM->add(createInstSimplifyLegacyPass());
@@ -834,7 +835,7 @@ void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level,
 
 // An LLVM module pass that just runs all julia passes in order. Useful for
 // debugging
-template <int OptLevel>
+template <int OptLevel, bool dump_native>
 class JuliaPipeline : public Pass {
 public:
     static char ID;
@@ -849,20 +850,27 @@ class JuliaPipeline : public Pass {
         PMTopLevelManager *TPM = Stack.top()->getTopLevelManager();
         TPMAdapter Adapter(TPM);
         addTargetPasses(&Adapter, &jl_ExecutionEngine->getTargetMachine());
-        addOptimizationPasses(&Adapter, OptLevel);
+        addOptimizationPasses(&Adapter, OptLevel, true, dump_native, true);
         addMachinePasses(&Adapter, &jl_ExecutionEngine->getTargetMachine(), OptLevel);
     }
     JuliaPipeline() : Pass(PT_PassManager, ID) {}
     Pass *createPrinterPass(raw_ostream &O, const std::string &Banner) const override {
         return createPrintModulePass(O, Banner);
     }
 };
-template<> char JuliaPipeline<0>::ID = 0;
-template<> char JuliaPipeline<2>::ID = 0;
-template<> char JuliaPipeline<3>::ID = 0;
-static RegisterPass<JuliaPipeline<0>> X("juliaO0", "Runs the entire julia pipeline (at -O0)", false, false);
-static RegisterPass<JuliaPipeline<2>> Y("julia", "Runs the entire julia pipeline (at -O2)", false, false);
-static RegisterPass<JuliaPipeline<3>> Z("juliaO3", "Runs the entire julia pipeline (at -O3)", false, false);
+template<> char JuliaPipeline<0,false>::ID = 0;
+template<> char JuliaPipeline<2,false>::ID = 0;
+template<> char JuliaPipeline<3,false>::ID = 0;
+template<> char JuliaPipeline<0,true>::ID = 0;
+template<> char JuliaPipeline<2,true>::ID = 0;
+template<> char JuliaPipeline<3,true>::ID = 0;
+static RegisterPass<JuliaPipeline<0,false>> X("juliaO0", "Runs the entire julia pipeline (at -O0)", false, false);
+static RegisterPass<JuliaPipeline<2,false>> Y("julia", "Runs the entire julia pipeline (at -O2)", false, false);
+static RegisterPass<JuliaPipeline<3,false>> Z("juliaO3", "Runs the entire julia pipeline (at -O3)", false, false);
+
+static RegisterPass<JuliaPipeline<0,true>> XS("juliaO0-sysimg", "Runs the entire julia pipeline (at -O0/sysimg mode)", false, false);
+static RegisterPass<JuliaPipeline<2,true>> YS("julia-sysimg", "Runs the entire julia pipeline (at -O2/sysimg mode)", false, false);
+static RegisterPass<JuliaPipeline<3,true>> ZS("juliaO3-sysimg", "Runs the entire julia pipeline (at -O3/sysimg mode)", false, false);
 
 extern "C" JL_DLLEXPORT
 void jl_add_optimization_passes_impl(LLVMPassManagerRef PM, int opt_level, int lower_intrinsics) {

src/jitlayers.cpp

@@ -18,6 +18,7 @@
 #include <llvm/Support/raw_ostream.h>
 #include <llvm/Transforms/Utils/Cloning.h>
 #include <llvm/Transforms/Utils/ModuleUtils.h>
+#include <llvm/Bitcode/BitcodeWriter.h>
 
 // target machine computation
 #include <llvm/CodeGen/TargetSubtargetInfo.h>

src/jitlayers.h

@@ -51,7 +51,7 @@ extern "C" jl_cgparams_t jl_default_cgparams;
 extern bool imaging_mode;
 
 void addTargetPasses(legacy::PassManagerBase *PM, TargetMachine *TM);
-void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level, bool lower_intrinsics=true, bool dump_native=false);
+void addOptimizationPasses(legacy::PassManagerBase *PM, int opt_level, bool lower_intrinsics=true, bool dump_native=false, bool external_use=false);
 void addMachinePasses(legacy::PassManagerBase *PM, TargetMachine *TM, int optlevel);
 void jl_finalize_module(std::unique_ptr<Module>  m);
 void jl_merge_module(Module *dest, std::unique_ptr<Module> src);
@@ -283,7 +283,7 @@ Pass *createPropagateJuliaAddrspaces();
 Pass *createRemoveJuliaAddrspacesPass();
 Pass *createRemoveNIPass();
 Pass *createJuliaLICMPass();
-Pass *createMultiVersioningPass();
+Pass *createMultiVersioningPass(bool external_use);
 Pass *createAllocOptPass();
 Pass *createDemoteFloat16Pass();
 Pass *createCPUFeaturesPass();

src/llvm-multiversioning.cpp

@@ -242,7 +242,7 @@ struct CloneCtx {
             return cast<Function>(vmap->lookup(orig_f));
         }
     };
-    CloneCtx(Module &M, function_ref<LoopInfo&(Function&)> GetLI, function_ref<CallGraph&()> GetCG);
+    CloneCtx(Module &M, function_ref<LoopInfo&(Function&)> GetLI, function_ref<CallGraph&()> GetCG, bool allow_bad_fvars);
     void clone_bases();
     void collect_func_infos();
     void clone_all_partials();
@@ -292,10 +292,11 @@ struct CloneCtx {
     std::set<uint32_t> alias_relocs;
     bool has_veccall{false};
     bool has_cloneall{false};
+    bool allow_bad_fvars{false};
 };
 
 template<typename T>
-static inline std::vector<T*> consume_gv(Module &M, const char *name)
+static inline std::vector<T*> consume_gv(Module &M, const char *name, bool allow_bad_fvars)
 {
     // Get information about sysimg export functions from the two global variables.
     // Strip them from the Module so that it's easier to handle the uses.
@@ -304,8 +305,17 @@ static inline std::vector<T*> consume_gv(Module &M, const char *name)
     auto *ary = cast<ConstantArray>(gv->getInitializer());
     unsigned nele = ary->getNumOperands();
     std::vector<T*> res(nele);
-    for (unsigned i = 0; i < nele; i++)
-        res[i] = cast<T>(ary->getOperand(i)->stripPointerCasts());
+    unsigned i = 0;
+    while (i < nele) {
+        llvm::Value *val = ary->getOperand(i)->stripPointerCasts();
+        if (allow_bad_fvars && (!isa<T>(val) || (isa<Function>(val) && cast<Function>(val)->isDeclaration()))) {
+            // Shouldn't happen in regular use, but can happen in bugpoint.
+            nele--;
+            continue;
+        }
+        res[i++] = cast<T>(val);
+    }
+    res.resize(nele);
     assert(gv->use_empty());
     gv->eraseFromParent();
     if (ary->use_empty())
@@ -314,14 +324,15 @@ static inline std::vector<T*> consume_gv(Module &M, const char *name)
 }
 
 // Collect basic information about targets and functions.
-CloneCtx::CloneCtx(Module &M, function_ref<LoopInfo&(Function&)> GetLI, function_ref<CallGraph&()> GetCG)
+CloneCtx::CloneCtx(Module &M, function_ref<LoopInfo&(Function&)> GetLI, function_ref<CallGraph&()> GetCG, bool allow_bad_fvars)
     : tbaa_const(tbaa_make_child_with_context(M.getContext(), "jtbaa_const", nullptr, true).first),
       specs(jl_get_llvm_clone_targets()),
-      fvars(consume_gv<Function>(M, "jl_sysimg_fvars")),
-      gvars(consume_gv<Constant>(M, "jl_sysimg_gvars")),
+      fvars(consume_gv<Function>(M, "jl_sysimg_fvars", allow_bad_fvars)),
+      gvars(consume_gv<Constant>(M, "jl_sysimg_gvars", false)),
       M(M),
       GetLI(GetLI),
-      GetCG(GetCG)
+      GetCG(GetCG),
+      allow_bad_fvars(allow_bad_fvars)
 {
     groups.emplace_back(0, specs[0]);
     uint32_t ntargets = specs.size();
@@ -636,6 +647,12 @@ uint32_t CloneCtx::get_func_id(Function *F)
 {
     auto &ref = func_ids[F];
     if (!ref) {
+        if (allow_bad_fvars && F->isDeclaration()) {
+            // This should never happen in regular use, but can happen if
+            // bugpoint deletes the function. Just do something here to
+            // allow bugpoint to proceed.
+            return (uint32_t)-1;
+        }
         fvars.push_back(F);
         ref = fvars.size();
     }
@@ -927,10 +944,15 @@ Constant *CloneCtx::emit_offset_table(const std::vector<T*> &vars, StringRef nam
 
 void CloneCtx::emit_metadata()
 {
+    uint32_t nfvars = fvars.size();
+    if (allow_bad_fvars && nfvars == 0) {
+        // Will result in a non-loadable sysimg, but `allow_bad_fvars` is for bugpoint only
+        return;
+    }
+
     // Store back the information about exported functions.
     auto fbase = emit_offset_table(fvars, "jl_sysimg_fvars");
     auto gbase = emit_offset_table(gvars, "jl_sysimg_gvars");
-    uint32_t nfvars = fvars.size();
 
     uint32_t ntargets = specs.size();
     SmallVector<Target*, 8> targets(ntargets);
@@ -1057,7 +1079,7 @@ void CloneCtx::emit_metadata()
     }
 }
 
-static bool runMultiVersioning(Module &M, function_ref<LoopInfo&(Function&)> GetLI, function_ref<CallGraph&()> GetCG)
+static bool runMultiVersioning(Module &M, function_ref<LoopInfo&(Function&)> GetLI, function_ref<CallGraph&()> GetCG, bool allow_bad_fvars)
 {
     // Group targets and identify cloning bases.
     // Also initialize function info maps (we'll update these maps as we go)
@@ -1070,7 +1092,13 @@ static bool runMultiVersioning(Module &M, function_ref<LoopInfo&(Function&)> Get
     if (M.getName() == "sysimage")
         return false;
 
-    CloneCtx clone(M, GetLI, GetCG);
+    GlobalVariable *fvars = M.getGlobalVariable("jl_sysimg_fvars");
+    GlobalVariable *gvars = M.getGlobalVariable("jl_sysimg_gvars");
+    if (allow_bad_fvars && (!fvars || !fvars->hasInitializer() || !isa<ConstantArray>(fvars->getInitializer()) ||
+                            !gvars || !gvars->hasInitializer() || !isa<ConstantArray>(gvars->getInitializer())))
+        return false;
+
+    CloneCtx clone(M, GetLI, GetCG, allow_bad_fvars);
 
     // Collect a list of original functions and clone base functions
     clone.clone_bases();
@@ -1110,8 +1138,8 @@ static bool runMultiVersioning(Module &M, function_ref<LoopInfo&(Function&)> Get
 
 struct MultiVersioningLegacy: public ModulePass {
     static char ID;
-    MultiVersioningLegacy()
-        : ModulePass(ID)
+    MultiVersioningLegacy(bool allow_bad_fvars=false)
+        : ModulePass(ID), allow_bad_fvars(allow_bad_fvars)
     {}
 
 private:
@@ -1122,6 +1150,7 @@ struct MultiVersioningLegacy: public ModulePass {
         AU.addRequired<CallGraphWrapperPass>();
         AU.addPreserved<LoopInfoWrapperPass>();
     }
+    bool allow_bad_fvars;
 };
 
 bool MultiVersioningLegacy::runOnModule(Module &M)
@@ -1132,7 +1161,7 @@ bool MultiVersioningLegacy::runOnModule(Module &M)
     auto GetCG = [this]() -> CallGraph & {
         return getAnalysis<CallGraphWrapperPass>().getCallGraph();
     };
-    return runMultiVersioning(M, GetLI, GetCG);
+    return runMultiVersioning(M, GetLI, GetCG, allow_bad_fvars);
 }
 
 
@@ -1152,20 +1181,20 @@ PreservedAnalyses MultiVersioning::run(Module &M, ModuleAnalysisManager &AM)
     auto GetCG = [&]() -> CallGraph & {
         return AM.getResult<CallGraphAnalysis>(M);
     };
-    if (runMultiVersioning(M, GetLI, GetCG)) {
+    if (runMultiVersioning(M, GetLI, GetCG, false)) {
         auto preserved = PreservedAnalyses::allInSet<CFGAnalyses>();
         preserved.preserve<LoopAnalysis>();
         return preserved;
     }
     return PreservedAnalyses::all();
 }
 
-Pass *createMultiVersioningPass()
+Pass *createMultiVersioningPass(bool allow_bad_fvars)
 {
-    return new MultiVersioningLegacy();
+    return new MultiVersioningLegacy(allow_bad_fvars);
 }
 
 extern "C" JL_DLLEXPORT void LLVMExtraAddMultiVersioningPass_impl(LLVMPassManagerRef PM)
 {
-    unwrap(PM)->add(createMultiVersioningPass());
+    unwrap(PM)->add(createMultiVersioningPass(false));
 }