For some targets, it's not possible to place GVs in the same memory buffer as the MachineCodeEmitter allocated memory. Code and data has different read / write / execution privilege requirements.

This is a short term workaround. The current solution is for the JIT memory manager to manage code and data memory separately.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58688 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/ExecutionEngine/JIT/JIT.cpp b/lib/ExecutionEngine/JIT/JIT.cpp
index b768f4d..83923a2 100644
--- a/lib/ExecutionEngine/JIT/JIT.cpp
+++ b/lib/ExecutionEngine/JIT/JIT.cpp
@@ -565,6 +565,16 @@ void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
     if (GV->isThreadLocal()) {
       MutexGuard locked(lock);
       Ptr = TJI.allocateThreadLocalMemory(S);
+    } else if (TJI.allocateSeparateGVMemory()) {
+      if (A <= 8) {
+        Ptr = malloc(S);
+      } else {
+        // Allocate S+A bytes of memory, then use an aligned pointer within that
+        // space.
+        Ptr = malloc(S+A);
+        unsigned MisAligned = ((intptr_t)Ptr & (A-1));
+        Ptr = (char*)Ptr + (MisAligned ? (A-MisAligned) : 0);
+      }
     } else {
       Ptr = MCE->allocateSpace(S, A);
     }