Add int-sub instruction

3 files changed, 15 insertions, 1 deletions

diff --git a/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java b/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java
index e98c4e02..c6544550 100644
--- a/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java
+++ b/src/main/java/org/shedlang/compiler/stackir/InstructionSerializer.java
@@ -90,6 +90,9 @@ public class InstructionSerializer {
 
             case IntNotEqualInstruction intNotEqual ->
                 treeList(treeIdentifier("int-ne"));
+
+            case IntSubInstruction intSub ->
+                treeList(treeIdentifier("int-sub"));
             
             case LocalLoadInstruction localLoadInstruction ->
                 treeList(
diff --git a/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java b/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
index 6be42213..6d361ddb 100644
--- a/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
+++ b/src/main/java/org/shedlang/compiler/stackir/instructions/Instruction.java
@@ -3,7 +3,7 @@ package org.shedlang.compiler.stackir.instructions;
 import org.shedlang.compiler.sources.Source;
 
 public sealed interface Instruction
-    permits CallInstruction, DefineFunctionInstruction, DiscardInstruction, FieldLoadInstruction, IntAddInstruction, IntEqualsInstruction, IntNotEqualInstruction, LocalLoadInstruction, LocalStoreInstruction, NamespaceFieldStoreInstruction, NamespaceImportInstruction, PushBoolInstruction, PushIntInstruction, PushStringInstruction, PushUnitInstruction, ReturnInstruction {
+    permits CallInstruction, DefineFunctionInstruction, DiscardInstruction, FieldLoadInstruction, IntAddInstruction, IntEqualsInstruction, IntNotEqualInstruction, IntSubInstruction, LocalLoadInstruction, LocalStoreInstruction, NamespaceFieldStoreInstruction, NamespaceImportInstruction, PushBoolInstruction, PushIntInstruction, PushStringInstruction, PushUnitInstruction, ReturnInstruction {
 
     Source source();
 }
diff --git a/src/main/java/org/shedlang/compiler/stackir/instructions/IntSubInstruction.java b/src/main/java/org/shedlang/compiler/stackir/instructions/IntSubInstruction.java
new file mode 100644
index 00000000..4d105695
--- /dev/null
+++ b/src/main/java/org/shedlang/compiler/stackir/instructions/IntSubInstruction.java
@@ -0,0 +1,11 @@
+package org.shedlang.compiler.stackir.instructions;
+
+import org.shedlang.compiler.sources.Source;
+
+/**
+ * Pop the right operand from the stack, then the left operand from the stack,
+ * calculate the left operand minus the right operand, then push the result onto
+ * the stack.
+ */
+public record IntSubInstruction(Source source) implements Instruction {
+}