feat: conditional select

1 files changed, 14 insertions, 0 deletions

diff --git a/src/ast.h b/src/ast.h
index 75d8b12..1db8b99 100644
--- a/src/ast.h
+++ b/src/ast.h
@@ -119,6 +119,7 @@ enum StatementKind
 	STATEMENT_CALL,
 	STATEMENT_STACK,
 	STATEMENT_INSTRUCTION,
+	STATEMENT_SELECT,
 };
 
 struct AssignStatement
@@ -187,6 +188,18 @@ struct InstructionStatement
 	size_t operand_capacity;
 };
 
+// a branchless conditional move: `target = if_value if left cmp right else
+// else_value`. Lowers to csel on AArch64 and cmov on x86.
+struct SelectStatement
+{
+	struct Token target;
+	struct Expr* if_value;
+	struct Expr* left;
+	struct Token comparison;
+	struct Expr* right;
+	struct Expr* else_value;
+};
+
 struct Statement
 {
 	enum StatementKind kind;
@@ -200,6 +213,7 @@ struct Statement
 		struct CallStatement call;
 		struct StackStatement stack;
 		struct InstructionStatement instruction;
+		struct SelectStatement select;
 	};
 };