stage2: improve addrspace handling

This commit changes the way Zig is intended to deal with variable
declaration for exotic targets. Where previously the idea was to
enfore local/global variables to be placed into their respective
address spaces, depending on the target, this is now fixed to the
generic address space.

To facilitate this for targets where local variables _must_ be
generated into a specific address space (ex. amdgcn where locals
must be generated into the private address space), the variable
allocations (alloca) are generated into the right address space
and then addrspace-casted back to the generic address space. While this
could be less efficient in theory, LLVM will hopefull deal with figuring
out the actual correct address space for a pointer for us. HIP seems to
do the same thing in this regard.

Global variables are handled in a similar way.

1 files changed, 11 insertions, 6 deletions

diff --git a/src/zig_llvm.cpp b/src/zig_llvm.cpp
index 4f9cd76c6a..b5edb336a5 100644
--- a/src/zig_llvm.cpp
+++ b/src/zig_llvm.cpp
@@ -512,22 +512,22 @@ LLVMValueRef ZigLLVMBuildUSubSat(LLVMBuilderRef B, LLVMValueRef LHS, LLVMValueRe
 
 LLVMValueRef ZigLLVMBuildSMulFixSat(LLVMBuilderRef B, LLVMValueRef LHS, LLVMValueRef RHS, const char *name) {
     llvm::Type* types[1] = {
-        unwrap(LHS)->getType(), 
+        unwrap(LHS)->getType(),
     };
     // pass scale = 0 as third argument
     llvm::Value* values[3] = {unwrap(LHS), unwrap(RHS), unwrap(B)->getInt32(0)};
-    
+
     CallInst *call_inst = unwrap(B)->CreateIntrinsic(Intrinsic::smul_fix_sat, types, values, nullptr, name);
     return wrap(call_inst);
 }
 
 LLVMValueRef ZigLLVMBuildUMulFixSat(LLVMBuilderRef B, LLVMValueRef LHS, LLVMValueRef RHS, const char *name) {
     llvm::Type* types[1] = {
-        unwrap(LHS)->getType(), 
+        unwrap(LHS)->getType(),
     };
     // pass scale = 0 as third argument
     llvm::Value* values[3] = {unwrap(LHS), unwrap(RHS), unwrap(B)->getInt32(0)};
-    
+
     CallInst *call_inst = unwrap(B)->CreateIntrinsic(Intrinsic::umul_fix_sat, types, values, nullptr, name);
     return wrap(call_inst);
 }
@@ -808,7 +808,7 @@ void ZigLLVMSetCurrentDebugLocation2(LLVMBuilderRef builder, unsigned int line,
         unsigned int column, ZigLLVMDIScope *scope, ZigLLVMDILocation *inlined_at)
 {
     DIScope* di_scope = reinterpret_cast<DIScope*>(scope);
-    DebugLoc debug_loc = DILocation::get(di_scope->getContext(), line, column, di_scope, 
+    DebugLoc debug_loc = DILocation::get(di_scope->getContext(), line, column, di_scope,
         reinterpret_cast<DILocation *>(inlined_at), false);
     unwrap(builder)->SetCurrentDebugLocation(debug_loc);
 }
@@ -1177,9 +1177,14 @@ LLVMValueRef ZigLLVMBuildAShrExact(LLVMBuilderRef builder, LLVMValueRef LHS, LLV
     return wrap(unwrap(builder)->CreateAShr(unwrap(LHS), unwrap(RHS), name, true));
 }
 
+LLVMValueRef ZigLLVMBuildAllocaInAddressSpace(LLVMBuilderRef builder, LLVMTypeRef Ty,
+        unsigned AddressSpace, const char *Name) {
+  return wrap(unwrap(builder)->CreateAlloca(unwrap(Ty), AddressSpace, nullptr, Name));
+}
+
 void ZigLLVMSetTailCall(LLVMValueRef Call) {
     unwrap<CallInst>(Call)->setTailCallKind(CallInst::TCK_MustTail);
-} 
+}
 
 void ZigLLVMSetCallSret(LLVMValueRef Call, LLVMTypeRef return_type) {
     CallInst *call_inst = unwrap<CallInst>(Call);