Add a type_checked_load_relative to support relative function pointer tables

This adds a type_checked_load_relative intrinsic whose semantics it is to
load a relative function pointer.

A relative function pointer is a pointer to a 32bit value that when
added to its address yields the address of the function.

Differential Revision: https://reviews.llvm.org/D143204

1 files changed, 6 insertions, 1 deletions

diff --git a/llvm/lib/LTO/LTO.cpp b/llvm/lib/LTO/LTO.cpp
index 6b82c4e..65ba3cb 100644
--- a/llvm/lib/LTO/LTO.cpp
+++ b/llvm/lib/LTO/LTO.cpp
@@ -1087,11 +1087,16 @@ Error LTO::checkPartiallySplit() {
       Intrinsic::getName(Intrinsic::type_test));
   Function *TypeCheckedLoadFunc = RegularLTO.CombinedModule->getFunction(
       Intrinsic::getName(Intrinsic::type_checked_load));
+  Function *TypeCheckedLoadRelativeFunc =
+      RegularLTO.CombinedModule->getFunction(
+          Intrinsic::getName(Intrinsic::type_checked_load_relative));
 
   // First check if there are type tests / type checked loads in the
   // merged regular LTO module IR.
   if ((TypeTestFunc && !TypeTestFunc->use_empty()) ||
-      (TypeCheckedLoadFunc && !TypeCheckedLoadFunc->use_empty()))
+      (TypeCheckedLoadFunc && !TypeCheckedLoadFunc->use_empty()) ||
+      (TypeCheckedLoadRelativeFunc &&
+       !TypeCheckedLoadRelativeFunc->use_empty()))
     return make_error<StringError>(
         "inconsistent LTO Unit splitting (recompile with -fsplit-lto-unit)",
         inconvertibleErrorCode());