Use correct type for memory addresses

3 files changed, 11 insertions, 3 deletions

diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/PatioToWasm.java b/src/main/java/org/shedlang/compiler/backends/wasm/PatioToWasm.java
index 3389bb65..96217cc5 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/PatioToWasm.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/PatioToWasm.java
@@ -549,7 +549,10 @@ public class PatioToWasm {
 
             case PatioDataPtr patioDataPtr -> {
                 var wasmMemoryAddress = new WasmMemoryAddress(patioDataPtr.name());
-                yield context.addInstruction(new WasmMemoryAddressConst(wasmMemoryAddress));
+                yield context.addInstruction(new WasmMemoryAddressConst(
+                    context.platformTarget.indexType(),
+                    wasmMemoryAddress
+                ));
             }
 
             case PatioFunctionPtr patioFunctionPtr -> {
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/instructions/WasmMemoryAddressConst.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/instructions/WasmMemoryAddressConst.java
index 74b8816d..6f36b01a 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/instructions/WasmMemoryAddressConst.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/ast/instructions/WasmMemoryAddressConst.java
@@ -1,13 +1,15 @@
 package org.shedlang.compiler.backends.wasm.structure.ast.instructions;
 
 import org.shedlang.compiler.backends.wasm.structure.ast.linking.WasmMemoryAddress;
+import org.shedlang.compiler.backends.wasm.structure.ast.types.WasmIndexType;
 
 /**
- * This is a fake instruction that corresponds to an i32.const instruction for
+ * This is a fake instruction that corresponds to an iNN.const instruction for
  * an offset into a data segment. Encapsulating this in its own instruction
  * avoids having to separately track relocation.
  */
 public record WasmMemoryAddressConst(
+    WasmIndexType indexType,
     WasmMemoryAddress address
 ) implements WasmInstruction {
 }
diff --git a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java
index 0d006c03..e7cefe21 100644
--- a/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java
+++ b/src/main/java/org/shedlang/compiler/backends/wasm/structure/binary/WasmBinaryFormatInstructions.java
@@ -193,7 +193,10 @@ public class WasmBinaryFormatInstructions {
             // == Relocatable Instructions ==
 
             case WasmMemoryAddressConst memoryAddressConst -> {
-                writer.writeByte(0x41);
+                writer.writeByte(switch (memoryAddressConst.indexType()) {
+                    case I32 -> 0x41;
+                    case I64 -> 0x42;
+                });
                 writer.writeMemoryAddressConst(memoryAddressConst.address());
             }