[ORC] Fix sorting of contructors by priority

[Hahnfeld]

Summary

The code was incorrectly sorting by the function address.

[Hahnfeld]

ping @lhames

[lhames]

LGTM. Thanks @Hahnfeld.

llvm/lib/ExecutionEngine/Orc/LLJIT.cpp

auto RegisterCOrDtors = [&](GlobalVariable *GlobalCOrDtors,
       std::vector<std::pair<Function *, unsigned>> InitsOrDeInits;
       auto COrDtors = isCtor ? getConstructors(M) : getDestructors(M);
 
       for (auto E : COrDtors)
         InitsOrDeInits.push_back(std::make_pair(E.Func, E.Priority));
       llvm::sort(InitsOrDeInits,
                  [](const std::pair<Function *, unsigned> &LHS,
                     const std::pair<Function *, unsigned> &RHS) {
-                   return LHS.first < RHS.first;
+                   return LHS.second < RHS.second;
                  });
 
       auto *InitOrDeInitFuncEntryBlock =
           BasicBlock::Create(Ctx, "entry", InitOrDeInitFunc);
       IRBuilder<> IB(InitOrDeInitFuncEntryBlock);
       for (auto &KV : InitsOrDeInits)
         IB.CreateCall(KV.first);
       IB.CreateRetVoid();

llvm/test/ExecutionEngine/OrcLazy/global-ctors-and-dtors.ll

 ; Test that global constructors and destructors are run:
 ;
 ; RUN: lli -jit-kind=orc-lazy -orc-lazy-debug=funcs-to-stdout -extra-module %s \
 ; RUN:   %S/Inputs/noop-main.ll | FileCheck %s
 ;
 ; Test that this is true for global constructors and destructors in other
 ; JITDylibs.
 ; RUN: lli -jit-kind=orc-lazy -orc-lazy-debug=funcs-to-stdout \
 ; RUN:   -jd extra -extra-module %s -jd main %S/Inputs/noop-main.ll | FileCheck %s
 ;
+; CHECK: Hello from constructor
 ; CHECK: Hello
 ; CHECK: [ {{.*}}main{{.*}} ]
 ; CHECK: Goodbye
 ; CHECK: Goodbye again
 
 %class.Foo = type { i8 }
 
 @f = global %class.Foo zeroinitializer, align 1
 @__dso_handle = external global i8
[e-mail]_ctors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__sub_I_hello.cpp, i8* null }] 
[e-mail]_ctors = appending global [2 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 65535, void ()* @_GLOBAL__sub_I_hello.cpp, i8* null }, { i32, void ()*, i8* } { i32 1024, void ()* @constructor, i8* null }]
 @llvm.global_dtors = appending global [1 x { i32, void ()*, i8* }] [{ i32, void ()*, i8* } { i32 0, void ()* @printf_wrapper, i8* null }]
 @str = private unnamed_addr constant [6 x i8] c"Hello\00"
 @str2 = private unnamed_addr constant [8 x i8] c"Goodbye\00"
 @str3 = global [14 x i8] c"Goodbye again\00"
+@str4 = private unnamed_addr constant [23 x i8] c"Hello from constructor\00"
 
 define linkonce_odr void @_ZN3FooD1Ev(%class.Foo* nocapture readnone %this) unnamed_addr align 2 {
 entry:
   %puts.i = tail call i32 @puts(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @str2, i64 0, i64 0))
   ret void
 }
 
 declare i32 @__cxa_atexit(void (i8*)*, i8*, i8*)
 
 define internal void @_GLOBAL__sub_I_hello.cpp() {
 entry:
   %puts.i.i.i = tail call i32 @puts(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @str, i64 0, i64 0))
   %0 = tail call i32 @__cxa_atexit(void (i8*)* bitcast (void (%class.Foo*)* @_ZN3FooD1Ev to void (i8*)*), i8* getelementptr inbounds (%class.Foo, %class.Foo* @f, i64 0, i32 0), i8* @__dso_handle)
   ret void
 }
 
 define void @printf_wrapper() {
 entry:
   %0 = tail call i32 @puts(i8* getelementptr inbounds ([14 x i8], [14 x i8]* @str3, i64 0, i64 0))
   ret void
 }
 
 declare i32 @puts(i8* nocapture readonly)
+
+define void @constructor() {
+entry:
+  %0 = tail call i32 @puts(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @str4, i64 0, i64 0))
+  ret void
+}