[RuntimeDyldChecker][AArch32] Add a PC offset to next_PC for ARM targets (#91746)

In ARM mode, the Program Counter (PC) points to the current instruction's
address + 8 instead of + 4. An offset is added to RuntimeDyldChecker to
use `next_pc` expression in JITLink tests with both Thumb and Arm.

1 files changed, 7 insertions, 1 deletions

diff --git a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
index 11fb21a..b98d455 100644
--- a/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
+++ b/llvm/lib/ExecutionEngine/RuntimeDyld/RuntimeDyldChecker.cpp
@@ -369,7 +369,13 @@ private:
     uint64_t SymbolAddr = PCtx.IsInsideLoad
                               ? Checker.getSymbolLocalAddr(Symbol)
                               : Checker.getSymbolRemoteAddr(Symbol);
-    uint64_t NextPC = SymbolAddr + InstSize;
+
+    // ARM PC offset is 8 instead of 4, because it accounts for an additional
+    // prefetch instruction that increments PC even though it is implicit.
+    auto TT = Checker.getTripleForSymbol(Checker.getTargetFlag(Symbol));
+    uint64_t PCOffset = TT.getArch() == Triple::ArchType::arm ? 4 : 0;
+
+    uint64_t NextPC = SymbolAddr + InstSize + PCOffset;
 
     return std::make_pair(EvalResult(NextPC), RemainingExpr);
   }