Support use of asm goto with outputs and `options(noreturn)`

When labels are present, the `noreturn` option really means that asm block
won't fallthrough -- if labels are present, then outputs can still be
meaningfully used.

3 files changed, 33 insertions, 3 deletions

diff --git a/tests/codegen/asm/goto.rs b/tests/codegen/asm/goto.rs
index 0e69c4d5840..3193d3aa145 100644
--- a/tests/codegen/asm/goto.rs
+++ b/tests/codegen/asm/goto.rs
@@ -43,11 +43,21 @@ pub unsafe fn asm_goto_with_outputs_use_in_label() -> u64 {
 // CHECK-LABEL: @asm_goto_noreturn
 #[no_mangle]
 pub unsafe fn asm_goto_noreturn() -> u64 {
-    let out: u64;
     // CHECK: callbr void asm sideeffect alignstack inteldialect "
     // CHECK-NEXT: to label %unreachable [label %[[JUMPBB:[a-b0-9]+]]]
     asm!("jmp {}", label { return 1; }, options(noreturn));
     // CHECK: [[JUMPBB]]:
     // CHECK-NEXT: ret i64 1
+}
+
+// CHECK-LABEL: @asm_goto_noreturn_with_outputs
+#[no_mangle]
+pub unsafe fn asm_goto_noreturn_with_outputs() -> u64 {
+    let out: u64;
+    // CHECK: [[RES:%[0-9]+]] = callbr i64 asm sideeffect alignstack inteldialect "
+    // CHECK-NEXT: to label %[[FALLTHROUGHBB:[a-b0-9]+]] [label %[[JUMPBB:[a-b0-9]+]]]
+    asm!("mov {}, 1", "jmp {}", out(reg) out, label { return out; });
+    // CHECK: [[JUMPBB]]:
+    // CHECK-NEXT: ret i64 [[RES]]
     out
 }
diff --git a/tests/ui/asm/x86_64/goto.rs b/tests/ui/asm/x86_64/goto.rs
index ab22317c458..d23018a05f5 100644
--- a/tests/ui/asm/x86_64/goto.rs
+++ b/tests/ui/asm/x86_64/goto.rs
@@ -65,6 +65,25 @@ fn goto_out_jump() {
     }
 }
 
+fn goto_out_jump_noreturn() {
+    unsafe {
+        let mut value = false;
+        let mut out: usize;
+        asm!(
+            "lea {}, [{} + 1]",
+            "jmp {}",
+            out(reg) out,
+            in(reg) 0x12345678usize,
+            label {
+                value = true;
+                assert_eq!(out, 0x12345679);
+            },
+            options(noreturn)
+        );
+        assert!(value);
+    }
+}
+
 // asm goto with outputs cause miscompilation in LLVM when multiple outputs are present.
 // The code sample below is adapted from https://github.com/llvm/llvm-project/issues/74483
 // and does not work with `-C opt-level=0`
@@ -131,6 +150,7 @@ fn main() {
     goto_jump();
     goto_out_fallthrough();
     goto_out_jump();
+    goto_out_jump_noreturn();
     // goto_multi_out();
     goto_noreturn();
     goto_noreturn_diverge();
diff --git a/tests/ui/asm/x86_64/goto.stderr b/tests/ui/asm/x86_64/goto.stderr
index 216b4d252ec..8f89e2b1290 100644
--- a/tests/ui/asm/x86_64/goto.stderr
+++ b/tests/ui/asm/x86_64/goto.stderr
@@ -1,5 +1,5 @@
 warning: unreachable statement
-  --> $DIR/goto.rs:124:9
+  --> $DIR/goto.rs:143:9
    |
 LL | /         asm!(
 LL | |             "jmp {}",
@@ -13,7 +13,7 @@ LL |           unreachable!();
    |           ^^^^^^^^^^^^^^ unreachable statement
    |
 note: the lint level is defined here
-  --> $DIR/goto.rs:114:8
+  --> $DIR/goto.rs:133:8
    |
 LL | #[warn(unreachable_code)]
    |        ^^^^^^^^^^^^^^^^