From bf3ef0da0c630ab239e4f26e86602eabe585e74f Mon Sep 17 00:00:00 2001
From: Luqman Aden <me@luqman.ca>
Date: Sat, 9 Apr 2022 15:25:46 -0400
Subject: [PATCH 1/2] Switch to the 'normal' basic block for writing asm
 outputs if needed.

We may sometimes emit an `invoke` instead of a `call` for inline
assembly during the MIR -> LLVM IR lowering. But we failed to update
the IR builder's current basic block before writing the results to the
outputs. This would result in invalid IR because the basic block would
end in a `store` instruction, which isn't a valid terminator.
---
 compiler/rustc_codegen_llvm/src/asm.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/compiler/rustc_codegen_llvm/src/asm.rs b/compiler/rustc_codegen_llvm/src/asm.rs
index 03c390b4bd4..91d132eb343 100644
--- a/compiler/rustc_codegen_llvm/src/asm.rs
+++ b/compiler/rustc_codegen_llvm/src/asm.rs
@@ -290,6 +290,11 @@ impl<'ll, 'tcx> AsmBuilderMethods<'tcx> for Builder<'_, 'll, 'tcx> {
         }
         attributes::apply_to_callsite(result, llvm::AttributePlace::Function, &{ attrs });
 
+        // Switch to the 'normal' basic block if we did an `invoke` instead of a `call`
+        if let Some((dest, _, _)) = dest_catch_funclet {
+            self.switch_to_block(dest);
+        }
+
         // Write results to outputs
         for (idx, op) in operands.iter().enumerate() {
             if let InlineAsmOperandRef::Out { reg, place: Some(place), .. }

From 0b2f3604fd733db5ad9498eaf129655879c242b3 Mon Sep 17 00:00:00 2001
From: Luqman Aden <me@luqman.ca>
Date: Sat, 9 Apr 2022 15:16:38 -0700
Subject: [PATCH 2/2] Update asm-may_unwind test to handle use of asm with
 outputs.

---
 src/test/codegen/asm-may_unwind.rs | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/test/codegen/asm-may_unwind.rs b/src/test/codegen/asm-may_unwind.rs
index 3b34d79c3a9..bf4202764a7 100644
--- a/src/test/codegen/asm-may_unwind.rs
+++ b/src/test/codegen/asm-may_unwind.rs
@@ -18,10 +18,23 @@ impl Drop for Foo {
     }
 }
 
-// CHECK-LABEL: @may_unwind
+// CHECK-LABEL: @asm_may_unwind
 #[no_mangle]
-pub unsafe fn may_unwind() {
+pub unsafe fn asm_may_unwind() {
     let _m = Foo;
     // CHECK: invoke void asm sideeffect alignstack inteldialect unwind ""
     asm!("", options(may_unwind));
 }
+
+// CHECK-LABEL: @asm_with_result_may_unwind
+#[no_mangle]
+pub unsafe fn asm_with_result_may_unwind() -> u64 {
+    let _m = Foo;
+    let res: u64;
+    // CHECK: [[RES:%[0-9]+]] = invoke i64 asm sideeffect alignstack inteldialect unwind
+    // CHECK-NEXT: to label %[[NORMALBB:[a-b0-9]+]]
+    asm!("mov {}, 1", out(reg) res, options(may_unwind));
+    // CHECK: [[NORMALBB]]:
+    // CHECK: ret i64 [[RES:%[0-9]+]]
+    res
+}