Construct constant LLVMPtr correctly (#38958)

Co-authored-by: Julian Samaroo <jpsamaroo@jpsamaroo.me>

Co-authored-by: Julian Samaroo <jpsamaroo@jpsamaroo.me>
(cherry picked from commit ec386bd)

Author: 2 people

src/intrinsics.cpp

@@ -168,7 +168,7 @@ static Constant *julia_const_to_llvm(jl_codectx_t &ctx, const void *ptr, jl_data
         return ConstantFP::get(jl_LLVMContext,
                 APFloat(lt->getFltSemantics(), APInt(64, data64)));
     }
-    if (lt->isFloatingPointTy() || lt->isIntegerTy()) {
+    if (lt->isFloatingPointTy() || lt->isIntegerTy() || lt->isPointerTy()) {
         int nb = jl_datatype_size(bt);
         APInt val(8 * nb, 0);
         void *bits = const_cast<uint64_t*>(val.getRawData());
@@ -178,6 +178,11 @@ static Constant *julia_const_to_llvm(jl_codectx_t &ctx, const void *ptr, jl_data
             return ConstantFP::get(jl_LLVMContext,
                     APFloat(lt->getFltSemantics(), val));
         }
+        if (lt->isPointerTy()) {
+            Type *Ty = IntegerType::get(jl_LLVMContext, 8 * nb);
+            Constant *addr = ConstantInt::get(Ty, val);
+            return ConstantExpr::getIntToPtr(addr, lt);
+        }
         assert(cast<IntegerType>(lt)->getBitWidth() == 8u * nb);
         return ConstantInt::get(lt, val);
     }
@@ -257,8 +262,10 @@ static Constant *julia_const_to_llvm(jl_codectx_t &ctx, const void *ptr, jl_data
         return ConstantVector::get(fields);
     if (StructType *st = dyn_cast<StructType>(lt))
         return ConstantStruct::get(st, fields);
-    ArrayType *at = cast<ArrayType>(lt);
-    return ConstantArray::get(at, fields);
+    if (ArrayType *at = dyn_cast<ArrayType>(lt))
+        return ConstantArray::get(at, fields);
+    assert(false && "Unknown LLVM type");
+    jl_unreachable();
 }
 
 static Constant *julia_const_to_llvm(jl_codectx_t &ctx, jl_value_t *e)

test/llvmcall.jl

@@ -237,3 +237,15 @@ end
 # issue 34166
 f34166(x) = Base.llvmcall("ret i$(Sys.WORD_SIZE) %0", Int, (Int,), x)
 @test_throws ErrorException f34166(1)
+
+# Test that codegen can construct constant LLVMPtr #38864
+struct MyStruct
+    kern::UInt64
+    ptr::Core.LLVMPtr{UInt8,1}
+end
+MyStruct(kern) = MyStruct(kern, reinterpret(Core.LLVMPtr{UInt8,1}, 0))
+MyStruct() = MyStruct(0)
+s = MyStruct()
+
+@test s.kern == 0
+@test reinterpret(Int, s.ptr) == 0