WASM: add support of offset field in memory operations

core/src/main/java/org/teavm/backend/wasm/generate/WasmGenerationVisitor.java

@@ -96,6 +96,7 @@ import org.teavm.backend.wasm.model.expression.WasmLoadFloat32;
 import org.teavm.backend.wasm.model.expression.WasmLoadFloat64;
 import org.teavm.backend.wasm.model.expression.WasmLoadInt32;
 import org.teavm.backend.wasm.model.expression.WasmLoadInt64;
+import org.teavm.backend.wasm.model.expression.WasmMemoryAccess;
 import org.teavm.backend.wasm.model.expression.WasmReturn;
 import org.teavm.backend.wasm.model.expression.WasmSetLocal;
 import org.teavm.backend.wasm.model.expression.WasmStoreFloat32;
@@ -472,34 +473,41 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
         WasmExpression address = getAddress(qualified, field, location);
         ValueType type = context.getFieldType(field);
         accept(value);
+
+        WasmMemoryAccess resultExpr;
         if (type instanceof ValueType.Primitive) {
             switch (((ValueType.Primitive) type).getKind()) {
                 case BOOLEAN:
                 case BYTE:
-                    result = new WasmStoreInt32(1, address, result, WasmInt32Subtype.INT8);
+                    resultExpr = new WasmStoreInt32(1, address, result, WasmInt32Subtype.INT8);
                     break;
                 case SHORT:
-                    result = new WasmStoreInt32(2, address, result, WasmInt32Subtype.INT16);
+                    resultExpr = new WasmStoreInt32(2, address, result, WasmInt32Subtype.INT16);
                     break;
                 case CHARACTER:
-                    result = new WasmStoreInt32(2, address, result, WasmInt32Subtype.UINT16);
+                    resultExpr = new WasmStoreInt32(2, address, result, WasmInt32Subtype.UINT16);
                     break;
                 case INTEGER:
-                    result = new WasmStoreInt32(4, address, result, WasmInt32Subtype.INT32);
+                    resultExpr = new WasmStoreInt32(4, address, result, WasmInt32Subtype.INT32);
                     break;
                 case LONG:
-                    result = new WasmStoreInt64(8, address, result, WasmInt64Subtype.INT64);
+                    resultExpr = new WasmStoreInt64(8, address, result, WasmInt64Subtype.INT64);
                     break;
                 case FLOAT:
-                    result = new WasmStoreFloat32(4, address, result);
+                    resultExpr = new WasmStoreFloat32(4, address, result);
                     break;
                 case DOUBLE:
-                    result = new WasmStoreFloat64(8, address, result);
+                    resultExpr = new WasmStoreFloat64(8, address, result);
                     break;
+                default:
+                    throw new AssertionError(type.toString());
             }
         } else {
-            result = new WasmStoreInt32(4, address, result, WasmInt32Subtype.INT32);
+            resultExpr = new WasmStoreInt32(4, address, result, WasmInt32Subtype.INT32);
         }
+
+        resultExpr.setOffset(getOffset(qualified, field));
+        result = (WasmExpression) resultExpr;
         result.setLocation(location);
     }
 
@@ -948,12 +956,18 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
         slotExpr.acceptVisitor(this);
         WasmExpression slotOffset = getSlotOffset(result);
         WasmExpression address = new WasmGetLocal(stackVariable);
+        if (!(slotOffset instanceof WasmInt32Constant)) {
             address = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.ADD, address, slotOffset);
+        }
 
         gcRootExpr.acceptVisitor(this);
         WasmExpression gcRoot = result;
 
-        result = new WasmStoreInt32(4, address, gcRoot, WasmInt32Subtype.INT32);
+        WasmStoreInt32 store = new WasmStoreInt32(4, address, gcRoot, WasmInt32Subtype.INT32);
+        if (slotOffset instanceof WasmInt32Constant) {
+            store.setOffset(((WasmInt32Constant) slotOffset).getValue());
+        }
+        result = store;
     }
 
     private void generateRemoveGcRoot(Expr slotExpr) {
@@ -965,9 +979,15 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
         slotExpr.acceptVisitor(this);
         WasmExpression slotOffset = getSlotOffset(result);
         WasmExpression address = new WasmGetLocal(stackVariable);
+        if (!(slotOffset instanceof WasmInt32Constant)) {
             address = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.ADD, address, slotOffset);
+        }
 
-        result = new WasmStoreInt32(4, address, new WasmInt32Constant(0), WasmInt32Subtype.INT32);
+        WasmStoreInt32 store = new WasmStoreInt32(4, address, new WasmInt32Constant(0), WasmInt32Subtype.INT32);
+        if (slotOffset instanceof WasmInt32Constant) {
+            store.setOffset(((WasmInt32Constant) slotOffset).getValue());
+        }
+        result = store;
     }
 
     private WasmExpression getSlotOffset(WasmExpression slot) {
@@ -1008,56 +1028,59 @@ class WasmGenerationVisitor implements StatementVisitor, ExprVisitor {
         WasmExpression address = getAddress(expr.getQualified(), expr.getField(), expr.getLocation());
 
         ValueType type = context.getFieldType(expr.getField());
+        WasmMemoryAccess resultExpr;
         if (type instanceof ValueType.Primitive) {
             switch (((ValueType.Primitive) type).getKind()) {
                 case BOOLEAN:
                 case BYTE:
-                    result = new WasmLoadInt32(1, address, WasmInt32Subtype.INT8);
+                    resultExpr = new WasmLoadInt32(1, address, WasmInt32Subtype.INT8);
                     break;
                 case SHORT:
-                    result = new WasmLoadInt32(2, address, WasmInt32Subtype.INT16);
+                    resultExpr = new WasmLoadInt32(2, address, WasmInt32Subtype.INT16);
                     break;
                 case CHARACTER:
-                    result = new WasmLoadInt32(2, address, WasmInt32Subtype.UINT16);
+                    resultExpr = new WasmLoadInt32(2, address, WasmInt32Subtype.UINT16);
                     break;
                 case INTEGER:
-                    result = new WasmLoadInt32(4, address, WasmInt32Subtype.INT32);
+                    resultExpr = new WasmLoadInt32(4, address, WasmInt32Subtype.INT32);
                     break;
                 case LONG:
-                    result = new WasmLoadInt64(8, address, WasmInt64Subtype.INT64);
+                    resultExpr = new WasmLoadInt64(8, address, WasmInt64Subtype.INT64);
                     break;
                 case FLOAT:
-                    result = new WasmLoadFloat32(4, address);
+                    resultExpr = new WasmLoadFloat32(4, address);
                     break;
                 case DOUBLE:
-                    result = new WasmLoadFloat64(8, address);
+                    resultExpr = new WasmLoadFloat64(8, address);
                     break;
+                default:
+                    throw new AssertionError(type.toString());
             }
         } else {
-            result = new WasmLoadInt32(4, address, WasmInt32Subtype.INT32);
+            resultExpr = new WasmLoadInt32(4, address, WasmInt32Subtype.INT32);
         }
+
+        resultExpr.setOffset(getOffset(expr.getQualified(), expr.getField()));
+        result = (WasmExpression) resultExpr;
     }
 
     private WasmExpression getAddress(Expr qualified, FieldReference field, TextLocation location) {
-        int offset = classGenerator.getFieldOffset(field);
         if (qualified == null) {
+            int offset = classGenerator.getFieldOffset(field);
             WasmExpression result = new WasmInt32Constant(offset);
             result.setLocation(location);
             return result;
         } else {
             accept(qualified);
-            if (offset != 0) {
-                WasmExpression offsetExpr = new WasmInt32Constant(offset);
-                offsetExpr.setLocation(qualified.getLocation());
-
-                WasmExpression address = new WasmIntBinary(WasmIntType.INT32, WasmIntBinaryOperation.ADD,
-                        result, offsetExpr);
-                address.setLocation(location);
-                return address;
-            } else {
             return result;
         }
     }
+
+    private int getOffset(Expr qualified, FieldReference field) {
+        if (qualified == null) {
+            return 0;
+        }
+        return classGenerator.getFieldOffset(field);
     }
 
     @Override

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmLoadFloat32.java

@@ -20,6 +20,7 @@ import java.util.Objects;
 public class WasmLoadFloat32 extends WasmExpression implements WasmMemoryAccess {
     private int alignment;
     private WasmExpression index;
+    private int offset;
 
     public WasmLoadFloat32(int alignment, WasmExpression index) {
         Objects.requireNonNull(index);
@@ -35,6 +36,16 @@ public class WasmLoadFloat32 extends WasmExpression implements WasmMemoryAccess
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmLoadFloat64.java

@@ -20,6 +20,7 @@ import java.util.Objects;
 public class WasmLoadFloat64 extends WasmExpression implements WasmMemoryAccess {
     private int alignment;
     private WasmExpression index;
+    private int offset;
 
     public WasmLoadFloat64(int alignment, WasmExpression index) {
         Objects.requireNonNull(index);
@@ -35,6 +36,16 @@ public class WasmLoadFloat64 extends WasmExpression implements WasmMemoryAccess
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmLoadInt32.java

@@ -21,6 +21,7 @@ public class WasmLoadInt32 extends WasmExpression implements WasmMemoryAccess {
     private int alignment;
     private WasmExpression index;
     private WasmInt32Subtype convertFrom;
+    private int offset;
 
     public WasmLoadInt32(int alignment, WasmExpression index, WasmInt32Subtype convertFrom) {
         Objects.requireNonNull(index);
@@ -38,6 +39,16 @@ public class WasmLoadInt32 extends WasmExpression implements WasmMemoryAccess {
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmLoadInt64.java

@@ -21,6 +21,7 @@ public class WasmLoadInt64 extends WasmExpression implements WasmMemoryAccess {
     private int alignment;
     private WasmExpression index;
     private WasmInt64Subtype convertFrom;
+    private int offset;
 
     public WasmLoadInt64(int alignment, WasmExpression index, WasmInt64Subtype convertFrom) {
         Objects.requireNonNull(index);
@@ -38,6 +39,16 @@ public class WasmLoadInt64 extends WasmExpression implements WasmMemoryAccess {
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmMemoryAccess.java

@@ -19,4 +19,8 @@ public interface WasmMemoryAccess {
     WasmExpression getIndex();
 
     void setIndex(WasmExpression index);
+
+    int getOffset();
+
+    void setOffset(int offset);
 }

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmStoreFloat32.java

@@ -21,6 +21,7 @@ public class WasmStoreFloat32 extends WasmExpression implements WasmMemoryAccess
     private int alignment;
     private WasmExpression index;
     private WasmExpression value;
+    private int offset;
 
     public WasmStoreFloat32(int alignment, WasmExpression index, WasmExpression value) {
         Objects.requireNonNull(index);
@@ -38,6 +39,16 @@ public class WasmStoreFloat32 extends WasmExpression implements WasmMemoryAccess
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmStoreFloat64.java

@@ -21,6 +21,7 @@ public class WasmStoreFloat64 extends WasmExpression implements WasmMemoryAccess
     private int alignment;
     private WasmExpression index;
     private WasmExpression value;
+    private int offset;
 
     public WasmStoreFloat64(int alignment, WasmExpression index, WasmExpression value) {
         Objects.requireNonNull(index);
@@ -38,6 +39,16 @@ public class WasmStoreFloat64 extends WasmExpression implements WasmMemoryAccess
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmStoreInt32.java

@@ -22,6 +22,7 @@ public class WasmStoreInt32 extends WasmExpression implements WasmMemoryAccess {
     private WasmExpression index;
     private WasmExpression value;
     private WasmInt32Subtype convertTo;
+    private int offset;
 
     public WasmStoreInt32(int alignment, WasmExpression index, WasmExpression value,
             WasmInt32Subtype convertTo) {
@@ -42,6 +43,16 @@ public class WasmStoreInt32 extends WasmExpression implements WasmMemoryAccess {
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/model/expression/WasmStoreInt64.java

@@ -22,6 +22,7 @@ public class WasmStoreInt64 extends WasmExpression implements WasmMemoryAccess {
     private WasmExpression index;
     private WasmExpression value;
     private WasmInt64Subtype convertTo;
+    private int offset;
 
     public WasmStoreInt64(int alignment, WasmExpression index, WasmExpression value,
             WasmInt64Subtype convertTo) {
@@ -42,6 +43,16 @@ public class WasmStoreInt64 extends WasmExpression implements WasmMemoryAccess {
         this.alignment = alignment;
     }
 
+    @Override
+    public int getOffset() {
+        return offset;
+    }
+
+    @Override
+    public void setOffset(int offset) {
+        this.offset = offset;
+    }
+
     @Override
     public WasmExpression getIndex() {
         return index;

core/src/main/java/org/teavm/backend/wasm/render/WasmBinaryRenderingVisitor.java

@@ -669,7 +669,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     @Override
@@ -699,7 +699,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     @Override
@@ -707,7 +707,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
         expression.getIndex().acceptVisitor(this);
         writer.writeByte(0x2C);
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     @Override
@@ -715,7 +715,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
         expression.getIndex().acceptVisitor(this);
         writer.writeByte(0x2D);
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     @Override
@@ -736,7 +736,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     @Override
@@ -761,7 +761,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     @Override
@@ -770,7 +770,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
         expression.getValue().acceptVisitor(this);
         writer.writeByte(0x35);
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     @Override
@@ -779,7 +779,7 @@ class WasmBinaryRenderingVisitor implements WasmExpressionVisitor {
         expression.getValue().acceptVisitor(this);
         writer.writeByte(0x36);
         writer.writeByte(alignment(expression.getAlignment()));
-        writer.writeByte(0);
+        writer.writeLEB(expression.getOffset());
     }
 
     private int alignment(int value) {

core/src/main/java/org/teavm/backend/wasm/render/WasmCRenderingVisitor.java

@@ -777,21 +777,22 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         }
 
         result.getLines().addAll(index.getLines());
+        String base = "&wasm_heap[" + index.getText() + " + " + expression.getOffset() + "]";
         switch (expression.getConvertFrom()) {
             case INT8:
-                result.setText("(int32_t) (int8_t) wasm_heap[" + index.getText() + "]");
+                result.setText("(int32_t) (int8_t) " + base.substring(1));
                 break;
             case UINT8:
-                result.setText("(int32_t) (uint8_t) wasm_heap[" + index.getText() + "]");
+                result.setText("(int32_t) (uint8_t) " + base.substring(1));
                 break;
             case INT16:
-                result.setText("(int32_t) *((int16_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("(int32_t) *((int16_t *) " + base + ")");
                 break;
             case UINT16:
-                result.setText("(int32_t) *((uint16_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("(int32_t) *((uint16_t *) " + base + ")");
                 break;
             case INT32:
-                result.setText("*((int32_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("*((int32_t *) " + base + ")");
                 break;
         }
 
@@ -812,27 +813,28 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         }
 
         result.getLines().addAll(index.getLines());
+        String base = "&wasm_heap[" + index.getText() + " + " + expression.getOffset() + "]";
         switch (expression.getConvertFrom()) {
             case INT8:
-                result.setText("(int64_t) (int8_t) wasm_heap[" + index.getText() + "]");
+                result.setText("(int64_t) (int8_t) " + base.substring(1));
                 break;
             case UINT8:
-                result.setText("(int64_t) (uint8_t) wasm_heap[" + index.getText() + "]");
+                result.setText("(int64_t) (uint8_t) " + base.substring(1));
                 break;
             case INT16:
-                result.setText("(int64_t) *((int16_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("(int64_t) *((int16_t *) " + base + ")");
                 break;
             case UINT16:
-                result.setText("(int64_t) *((uint16_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("(int64_t) *((uint16_t *) " + base + ")");
                 break;
             case INT32:
-                result.setText("(int64_t) *((int32_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("(int64_t) *((int32_t *) " + base + ")");
                 break;
             case UINT32:
-                result.setText("(int64_t) *((uint32_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("(int64_t) *((uint32_t *) " + base + ")");
                 break;
             case INT64:
-                result.setText("*((int64_t *) &wasm_heap[" + index.getText() + "])");
+                result.setText("*((int64_t *) " + base + ")");
                 break;
         }
 
@@ -853,7 +855,7 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         }
 
         result.getLines().addAll(index.getLines());
-        result.setText("*((float *) &wasm_heap[" + index.getText() + "])");
+        result.setText("*((float *) &wasm_heap[" + index.getText() + " + " + expression.getOffset() + "])");
 
         value = result;
     }
@@ -872,7 +874,7 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         }
 
         result.getLines().addAll(index.getLines());
-        result.setText("*((double *) &wasm_heap[" + index.getText() + "])");
+        result.setText("*((double *) &wasm_heap[" + index.getText() + " + " + expression.getOffset() + "])");
 
         value = result;
     }
@@ -893,21 +895,22 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         result.getLines().addAll(valueToStore.getLines());
 
         String line;
+        String base = "&wasm_heap[" + index.getText() + " + " + expression.getOffset() + "]";
         switch (expression.getConvertTo()) {
             case INT8:
-                line = "wasm_heap[" + index.getText() + "] = " + valueToStore.getText() + ";";
+                line = base.substring(1) + " = " + valueToStore.getText() + ";";
                 break;
             case UINT8:
-                line = "*((uint8_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((uint8_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case INT16:
-                line = "*((int16_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((int16_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case UINT16:
-                line = "*((uint16_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((uint16_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case INT32:
-                line = "*((int32_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((int32_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             default:
                 throw new AssertionError(expression.getConvertTo().toString());
@@ -933,27 +936,28 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         result.getLines().addAll(valueToStore.getLines());
 
         String line;
+        String base = "&wasm_heap[" + index.getText() + " + " + expression.getOffset() + "]";
         switch (expression.getConvertTo()) {
             case INT8:
-                line = "wasm_heap[" + index.getText() + "] = " + valueToStore.getText();
+                line = base.substring(1) + " = " + valueToStore.getText();
                 break;
             case UINT8:
-                line = "*((uint8_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((uint8_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case INT16:
-                line = "*((int16_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((int16_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case UINT16:
-                line = "*((uint16_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((uint16_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case INT32:
-                line = "*((int32_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((int32_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case UINT32:
-                line = "*((uint32_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((uint32_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             case INT64:
-                line = "*((int64_t *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";";
+                line = "*((int64_t *) " + base + ") = " + valueToStore.getText() + ";";
                 break;
             default:
                 throw new AssertionError();
@@ -979,8 +983,8 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         result.getLines().addAll(index.getLines());
         result.getLines().addAll(valueToStore.getLines());
 
-        result.addLine("*((float *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";",
+        result.addLine("*((float *) &wasm_heap[" + index.getText() + " + " + expression.getOffset() + "]) = "
-                expression.getLocation());
+                + valueToStore.getText() + ";", expression.getLocation());
 
         value = result;
     }
@@ -1000,8 +1004,8 @@ class WasmCRenderingVisitor implements WasmExpressionVisitor {
         result.getLines().addAll(index.getLines());
         result.getLines().addAll(valueToStore.getLines());
 
-        result.addLine("*((double *) &wasm_heap[" + index.getText() + "]) = " + valueToStore.getText() + ";",
+        result.addLine("*((double *) &wasm_heap[" + index.getText() + " + " + expression.getOffset() + "]) = "
-                expression.getLocation());
+                + valueToStore.getText() + ";", expression.getLocation());
 
         value = result;
     }

core/src/main/java/org/teavm/backend/wasm/render/WasmRenderingVisitor.java

@@ -399,6 +399,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         append(" align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         close();
     }
@@ -430,6 +433,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         append(" align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         close();
     }
@@ -437,6 +443,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
     @Override
     public void visit(WasmLoadFloat32 expression) {
         open().append("f32.load align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         close();
     }
@@ -444,6 +453,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
     @Override
     public void visit(WasmLoadFloat64 expression) {
         open().append("f64.load align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         close();
     }
@@ -465,6 +477,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         append(" align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         line(expression.getValue());
         close();
@@ -491,6 +506,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
                 break;
         }
         append(" align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         line(expression.getValue());
         close();
@@ -499,6 +517,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
     @Override
     public void visit(WasmStoreFloat32 expression) {
         open().append("f32.store align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         line(expression.getValue());
         close();
@@ -507,6 +528,9 @@ class WasmRenderingVisitor implements WasmExpressionVisitor {
     @Override
     public void visit(WasmStoreFloat64 expression) {
         open().append("f64.store align=" + expression.getAlignment());
+        if (expression.getOffset() > 0) {
+            append(" offset=" + expression.getOffset());
+        }
         line(expression.getIndex());
         line(expression.getValue());
         close();