stage2: implement `@clz` and `@ctz`

Also improve the LLVM backend to support lowering bigints to LLVM
values.

Moves over a bunch of math.zig test cases to the "passing for stage2"
section.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/codegen.zig b/src/codegen.zig
index 79105dc4a7..dfaedf041a 100644
--- a/src/codegen.zig
+++ b/src/codegen.zig
@@ -896,6 +896,8 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
                     .memset          => try self.airMemset(inst),
                     .set_union_tag   => try self.airSetUnionTag(inst),
                     .get_union_tag   => try self.airGetUnionTag(inst),
+                    .clz             => try self.airClz(inst),
+                    .ctz             => try self.airCtz(inst),
 
                     .atomic_store_unordered => try self.airAtomicStore(inst, .Unordered),
                     .atomic_store_monotonic => try self.airAtomicStore(inst, .Monotonic),
@@ -1606,6 +1608,22 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
             return self.finishAir(inst, result, .{ ty_op.operand, .none, .none });
         }
 
+        fn airClz(self: *Self, inst: Air.Inst.Index) !void {
+            const ty_op = self.air.instructions.items(.data)[inst].ty_op;
+            const result: MCValue = if (self.liveness.isUnused(inst)) .dead else switch (arch) {
+                else => return self.fail("TODO implement airClz for {}", .{self.target.cpu.arch}),
+            };
+            return self.finishAir(inst, result, .{ ty_op.operand, .none, .none });
+        }
+
+        fn airCtz(self: *Self, inst: Air.Inst.Index) !void {
+            const ty_op = self.air.instructions.items(.data)[inst].ty_op;
+            const result: MCValue = if (self.liveness.isUnused(inst)) .dead else switch (arch) {
+                else => return self.fail("TODO implement airCtz for {}", .{self.target.cpu.arch}),
+            };
+            return self.finishAir(inst, result, .{ ty_op.operand, .none, .none });
+        }
+
         fn reuseOperand(self: *Self, inst: Air.Inst.Index, operand: Air.Inst.Ref, op_index: Liveness.OperandInt, mcv: MCValue) bool {
             if (!self.liveness.operandDies(inst, op_index))
                 return false;