From d20490d25ef007b14b900665fe767ef44bcf3ee2 Mon Sep 17 00:00:00 2001
From: David Rubin <david@vortan.dev>
Date: Thu, 27 Nov 2025 19:16:29 -0800
Subject: [PATCH] c: support `+r` output constraint

---
 src/codegen/c.zig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/codegen/c.zig b/src/codegen/c.zig
index 4a84fafc619dc1d9e772680f29052eef81dc9ddd..6cfd5508760b3384cbf836187871852d3733c0a9 100644
--- a/src/codegen/c.zig
+++ b/src/codegen/c.zig
@@ -4790,7 +4790,8 @@ fn airAsm(f: *Function, inst: Air.Inst.Index) !CValue {
         while (it.next()) |output| {
             const constraint = output.constraint;
 
-            if (constraint.len < 2 or constraint[0] != '=' or
+            if (constraint.len < 2 or
+                (constraint[0] != '=' and constraint[0] != '+') or
                 (constraint[1] == '{' and constraint[constraint.len - 1] != '}'))
             {
                 return f.fail("CBE: constraint not supported: '{s}'", .{constraint});
-- 
2.54.0