RFR: 8377554: Load card table base and other values via AOTRuntimeConstants in AOT code

[Vladimir Kozlov]

On Mon, 23 Feb 2026 16:59:53 GMT, Andrew Dinn <adinn at openjdk.org> wrote:

> Generated stubs and nmethods embed some runtime-derived constants, such as the card table base, directly into code as instruction operands. AOT code generation cannot rely on these constants being valid between the assembly run and a production run and adjusting the constants at load time is not currently supported. So, instead AOT generation must employ code which loads the constants from a table whose address can be relocated at load time.

You also need this one for C2:

diff --git a/src/hotspot/share/opto/type.cpp b/src/hotspot/share/opto/type.cpp
index c637737eef9..47058a190ba 100644
--- a/src/hotspot/share/opto/type.cpp
+++ b/src/hotspot/share/opto/type.cpp
@@ -97,7 +97,7 @@ const Type::TypeInfo Type::_type_info[Type::lastype] = {
   { Bad,             T_ILLEGAL,    "vectorz:",      false, Op_VecZ,              relocInfo::none          },  // VectorZ
 #endif
   { Bad,             T_ADDRESS,    "anyptr:",       false, Op_RegP,              relocInfo::none          },  // AnyPtr
-  { Bad,             T_ADDRESS,    "rawptr:",       false, Op_RegP,              relocInfo::none          },  // RawPtr
+  { Bad,             T_ADDRESS,    "rawptr:",       false, Op_RegP,              relocInfo::external_word_type },  // RawPtr
   { Bad,             T_OBJECT,     "oop:",          true,  Op_RegP,              relocInfo::oop_type      },  // OopPtr
   { Bad,             T_OBJECT,     "inst:",         true,  Op_RegP,              relocInfo::oop_type      },  // InstPtr
   { Bad,             T_OBJECT,     "ary:",          true,  Op_RegP,              relocInfo::oop_type      },  // AryPtr

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PR Comment: https://git.openjdk.org/jdk/pull/29884#issuecomment-3949460468