fix test

Author: MarinPostma

tests/disas/winch/x64/atomic/rmw/i64_atomic_rmw32_subu.wat

@@ -4,28 +4,33 @@
 (module
   (memory 1 1 shared)
   (func (export "_start") (result i64)
-        (i64.atomic.rmw8.sub_u (i32.const 0) (i64.const 42))))
+        (i64.atomic.rmw32.sub_u (i32.const 0) (i64.const 42))))
 ;; wasm[0]::function[0]:
 ;;       pushq   %rbp
 ;;       movq    %rsp, %rbp
 ;;       movq    8(%rdi), %r11
 ;;       movq    0x10(%r11), %r11
 ;;       addq    $0x10, %r11
 ;;       cmpq    %rsp, %r11
-;;       ja      0x52
+;;       ja      0x61
 ;;   1c: movq    %rdi, %r14
 ;;       subq    $0x10, %rsp
 ;;       movq    %rdi, 8(%rsp)
 ;;       movq    %rsi, (%rsp)
 ;;       movq    $0x2a, %rax
 ;;       movl    $0, %ecx
+;;       andl    $3, %ecx
+;;       cmpl    $0, %ecx
+;;       jne     0x63
+;;   44: movl    $0, %ecx
 ;;       movq    0x58(%r14), %r11
 ;;       movq    (%r11), %rdx
 ;;       addq    %rcx, %rdx
-;;       negb    %al
-;;       lock xaddb %al, (%rdx)
-;;       movzbq  %al, %rax
+;;       negl    %eax
+;;       lock xaddl %eax, (%rdx)
+;;       movl    %eax, %eax
 ;;       addq    $0x10, %rsp
 ;;       popq    %rbp
 ;;       retq
-;;   52: ud2
+;;   61: ud2
+;;   63: ud2

winch/codegen/src/visitor.rs

@@ -2356,7 +2356,12 @@ where
     }
 
     fn visit_i64_atomic_rmw32_add_u(&mut self, arg: MemArg) -> Self::Output {
-        self.emit_atomic_rmw(&arg, RmwOp::Add, OperandSize::S32, None)
+        self.emit_atomic_rmw(
+            &arg,
+            RmwOp::Add,
+            OperandSize::S32,
+            Some(ExtendKind::I64Extend32U),
+        )
     }
 
     fn visit_i64_atomic_rmw_add(&mut self, arg: MemArg) -> Self::Output {
@@ -2408,7 +2413,12 @@ where
     }
 
     fn visit_i64_atomic_rmw32_sub_u(&mut self, arg: MemArg) -> Self::Output {
-        self.emit_atomic_rmw(&arg, RmwOp::Sub, OperandSize::S32, None)
+        self.emit_atomic_rmw(
+            &arg,
+            RmwOp::Sub,
+            OperandSize::S32,
+            Some(ExtendKind::I64Extend32U),
+        )
     }
 
     wasmparser::for_each_visit_operator!(def_unsupported);