CBE: addition and subtraction

1 files changed, 15 insertions, 0 deletions

diff --git a/src/codegen/c.zig b/src/codegen/c.zig
index 5d350f7bd5..99ac0cfe00 100644
--- a/src/codegen/c.zig
+++ b/src/codegen/c.zig
@@ -160,6 +160,8 @@ fn genFn(file: *C, decl: *Decl) !void {
             if (switch (inst.tag) {
                 .assembly => try genAsm(&ctx, inst.castTag(.assembly).?),
                 .call => try genCall(&ctx, inst.castTag(.call).?),
+                .add => try genBinOp(&ctx, inst.cast(Inst.BinOp).?, "+"),
+                .sub => try genBinOp(&ctx, inst.cast(Inst.BinOp).?, "-"),
                 .ret => try genRet(&ctx, inst.castTag(.ret).?),
                 .retvoid => try genRetVoid(&ctx),
                 .arg => try genArg(&ctx),
@@ -207,6 +209,19 @@ fn genIntCast(ctx: *Context, inst: *Inst.UnOp) !?[]u8 {
     return name;
 }
 
+fn genBinOp(ctx: *Context, inst: *Inst.BinOp, comptime operator: []const u8) !?[]u8 {
+    if (inst.base.isUnused())
+        return null;
+    const lhs = ctx.resolveInst(inst.lhs);
+    const rhs = ctx.resolveInst(inst.rhs);
+    const writer = ctx.file.main.writer();
+    const name = try ctx.name();
+    try writer.writeAll(indentation ++ "const ");
+    try renderType(ctx, writer, inst.base.ty);
+    try writer.print(" {} = {} " ++ operator ++ " {};\n", .{ name, lhs, rhs });
+    return name;
+}
+
 fn genCall(ctx: *Context, inst: *Inst.Call) !?[]u8 {
     const writer = ctx.file.main.writer();
     const header = ctx.file.header.writer();