From ad36df54951d562c6a0e2c59d37c85bd7d3c7b6b Mon Sep 17 00:00:00 2001
From: Monadic Cat <greenmonadcat@gmail.com>
Date: Fri, 10 Dec 2021 15:15:59 -0600
Subject: [PATCH] add support for Arm64Call relocations in cranelift-jit

---
 cranelift/jit/src/compiled_blob.rs | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/cranelift/jit/src/compiled_blob.rs b/cranelift/jit/src/compiled_blob.rs
index f00165dbab..5dfa6d4812 100644
--- a/cranelift/jit/src/compiled_blob.rs
+++ b/cranelift/jit/src/compiled_blob.rs
@@ -81,6 +81,17 @@ impl CompiledBlob {
                         write_unaligned(at as *mut i32, pcrel)
                     };
                 }
+                Reloc::Arm64Call => {
+                    let base = get_address(name);
+                    // The instruction is 32 bits long.
+                    let iptr = at as *mut u32;
+                    let diff = (base as isize) - (at as isize);
+                    // The lower 26 bits of the `bl` instruction form the
+                    // immediate offset argument.
+                    let chop = 32 - 26;
+                    let imm26 = ((diff >> 2) as u32) << chop >> chop;
+                    unsafe { *iptr |= imm26; }
+                }
                 _ => unimplemented!(),
             }
         }