[WebAssembly] Remove exnref and br_on_exn

This removes `exnref` type and `br_on_exn` instruction. This is
effectively NFC because most uses of these were already removed in the
previous CLs.

Reviewed By: dschuff, tlively

Differential Revision: https://reviews.llvm.org/D94041

1 files changed, 0 insertions, 18 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
index 6e3bdbf..13fcc19 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyRegStackify.cpp
@@ -864,24 +864,6 @@ bool WebAssemblyRegStackify::runOnMachineFunction(MachineFunction &MF) {
         if (WebAssembly::isArgument(DefI->getOpcode()))
           continue;
 
-        // Currently catch's return value register cannot be stackified, because
-        // the wasm LLVM backend currently does not support live-in values
-        // entering blocks, which is a part of multi-value proposal.
-        //
-        // Once we support live-in values of wasm blocks, this can be:
-        // catch                           ; push exnref value onto stack
-        // block exnref -> i32
-        // br_on_exn $__cpp_exception      ; pop the exnref value
-        // end_block
-        //
-        // But because we don't support it yet, the catch instruction's dst
-        // register should be assigned to a local to be propagated across
-        // 'block' boundary now.
-        //
-        // TODO: Fix this once we support the multivalue blocks
-        if (DefI->getOpcode() == WebAssembly::CATCH)
-          continue;
-
         MachineOperand *Def = DefI->findRegisterDefOperand(Reg);
         assert(Def != nullptr);