2 files changed, 29 insertions, 0 deletions
diff --git a/src/codegen/c.zig b/src/codegen/c.zig
index 16558c6e04..84bb3a211b 100644
--- a/src/codegen/c.zig
+++ b/src/codegen/c.zig
@@ -1825,6 +1825,7 @@ fn genBody(f: *Function, body: []const Air.Inst.Index) error{ AnalysisFail, OutO
             .tag_name         => try airTagName(f, inst),
             .error_name       => try airErrorName(f, inst),
             .splat            => try airSplat(f, inst),
+            .select           => try airSelect(f, inst),
             .shuffle          => try airShuffle(f, inst),
             .reduce           => try airReduce(f, inst),
             .aggregate_init   => try airAggregateInit(f, inst),
@@ -3794,6 +3795,21 @@ fn airSplat(f: *Function, inst: Air.Inst.Index) !CValue {
     return f.fail("TODO: C backend: implement airSplat", .{});
 }
 
+fn airSelect(f: *Function, inst: Air.Inst.Index) !CValue {
+    if (f.liveness.isUnused(inst)) return CValue.none;
+
+    const inst_ty = f.air.typeOfIndex(inst);
+    const ty_pl = f.air.instructions.items(.data)[inst].ty_pl;
+
+    const writer = f.object.writer();
+    const local = try f.allocLocal(inst_ty, .Const);
+    try writer.writeAll(" = ");
+
+    _ = local;
+    _ = ty_pl;
+    return f.fail("TODO: C backend: implement airSelect", .{});
+}
+
 fn airShuffle(f: *Function, inst: Air.Inst.Index) !CValue {
     if (f.liveness.isUnused(inst)) return CValue.none;
 
diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index c8ca540f59..00074d69d1 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -3444,6 +3444,7 @@ pub const FuncGen = struct {
                 .tag_name       => try self.airTagName(inst),
                 .error_name     => try self.airErrorName(inst),
                 .splat          => try self.airSplat(inst),
+                .select         => try self.airSelect(inst),
                 .shuffle        => try self.airShuffle(inst),
                 .reduce         => try self.airReduce(inst),
                 .aggregate_init => try self.airAggregateInit(inst),
@@ -6355,6 +6356,18 @@ pub const FuncGen = struct {
         return self.builder.buildShuffleVector(op_vector, undef_vector, mask_llvm_ty.constNull(), "");
     }
 
+    fn airSelect(self: *FuncGen, inst: Air.Inst.Index) !?*const llvm.Value {
+        if (self.liveness.isUnused(inst)) return null;
+
+        const pl_op = self.air.instructions.items(.data)[inst].pl_op;
+        const extra = self.air.extraData(Air.Bin, pl_op.payload).data;
+        const pred = try self.resolveInst(pl_op.operand);
+        const a = try self.resolveInst(extra.lhs);
+        const b = try self.resolveInst(extra.rhs);
+
+        return self.builder.buildSelect(pred, a, b, "");
+    }
+
     fn airShuffle(self: *FuncGen, inst: Air.Inst.Index) !?*const llvm.Value {
         if (self.liveness.isUnused(inst)) return null;