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+#### Note: this error code is no longer emitted by the compiler.
+
+Malformed inline assembly rejected by LLVM.
+
+Erroneous code example:
+
+```ignore (no longer emitted)
+#![feature(llvm_asm)]
+
+fn main() {
+    let rax: u64;
+    unsafe {
+        llvm_asm!("" :"={rax"(rax));
+        println!("Accumulator is: {}", rax);
+    }
+}
+```
+
+LLVM checks the validity of the constraints and the assembly string passed to
+it. This error implies that LLVM seems something wrong with the inline
+assembly call.
+
+In particular, it can happen if you forgot the closing bracket of a register
+constraint (see issue #51430), like in the previous code example.