From 2fc1f9b9716f8561c94ecdeb8196ac4ce582f318 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Tue, 10 Sep 2024 05:00:02 +0200
Subject: [PATCH] llvm: Don't use the optimized jump table construction logic
 for wasm.

---
 src/codegen/llvm.zig | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/codegen/llvm.zig b/src/codegen/llvm.zig
index 2f9f9e096b..c8eb37b30a 100644
--- a/src/codegen/llvm.zig
+++ b/src/codegen/llvm.zig
@@ -6544,6 +6544,12 @@ pub const FuncGen = struct {
 
         const jmp_table: ?SwitchDispatchInfo.JmpTable = jmp_table: {
             if (!is_dispatch_loop) break :jmp_table null;
+
+            // Workaround for:
+            // * https://github.com/llvm/llvm-project/blob/56905dab7da50bccfcceaeb496b206ff476127e1/llvm/lib/MC/WasmObjectWriter.cpp#L560
+            // * https://github.com/llvm/llvm-project/blob/56905dab7da50bccfcceaeb496b206ff476127e1/llvm/test/MC/WebAssembly/blockaddress.ll
+            if (zcu.comp.getTarget().isWasm()) break :jmp_table null;
+
             // On a 64-bit target, 1024 pointers in our jump table is about 8K of pointers. This seems just
             // about acceptable - it won't fill L1d cache on most CPUs.
             const max_table_len = 1024;