From d732dab9b048a1c0bc9a8f8ab5c8c6bcddd1cc48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alex=20R=C3=B8nne=20Petersen?= <alex@alexrp.com>
Date: Sun, 23 Aug 2026 15:15:48 +0200
Subject: [PATCH] llvm: add updated issue links for targets with @prefetch
 crashes

Also lift the restriction for ARM which seems to work now.

* https://github.com/llvm/llvm-project/issues/218236
* https://github.com/llvm/llvm-project/issues/218239
---
 src/codegen/llvm/FuncGen.zig | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/src/codegen/llvm/FuncGen.zig b/src/codegen/llvm/FuncGen.zig
index 6ddb1d7f73aa18c1792c08c4aad3e227176ff774..6e80a6a0017e61c25af84cd6581186fe9add95d8 100644
--- a/src/codegen/llvm/FuncGen.zig
+++ b/src/codegen/llvm/FuncGen.zig
@@ -6542,28 +6542,19 @@ fn airPrefetch(self: *FuncGen, inst: Air.Inst.Index) Allocator.Error!Builder.Val
     comptime assert(@backingInt(std.lang.PrefetchOptions.Cache.instruction) == 0);
     comptime assert(@backingInt(std.lang.PrefetchOptions.Cache.data) == 1);
 
-    // LLVM fails during codegen of instruction cache prefetchs for these architectures.
-    // This is an LLVM bug as the prefetch intrinsic should be a noop if not supported
-    // by the target.
-    // To work around this, don't emit llvm.prefetch in this case.
-    // See https://bugs.llvm.org/show_bug.cgi?id=21037
     const zcu = self.object.zcu;
     const target = zcu.getTarget();
     switch (prefetch.cache) {
         .instruction => switch (target.cpu.arch) {
+            // https://github.com/llvm/llvm-project/issues/218236
             .x86_64,
             .x86,
+            // https://github.com/llvm/llvm-project/issues/218239
             .powerpc,
             .powerpcle,
             .powerpc64,
             .powerpc64le,
             => return .none,
-            .arm, .armeb, .thumb, .thumbeb => {
-                switch (prefetch.rw) {
-                    .write => return .none,
-                    else => {},
-                }
-            },
             else => {},
         },
         .data => {},
-- 
2.54.0