Commit aa0906e9aa

joachimschmidt557 <joachim.schmidt557@outlook.com>
2021-01-02 18:53:11
stage2 x86_64: fix bug in Function.gen
Previously, the x86_64 backend would remove code for exitlude relocs if the jump amount were 0. This causes issues as earlier jumps rely on the jump being present at the same address.
master
1 parent 4400d2d
Changed files (1)
src
codegen.zig
src/codegen.zig
@@ -543,13 +543,10 @@ fn Function(comptime arch: std.Target.Cpu.Arch) type {
                         if (self.code.items.len >= math.maxInt(i32)) {
                             return self.fail(self.src, "unable to perform relocation: jump too far", .{});
                         }
-                        for (self.exitlude_jump_relocs.items) |jmp_reloc| {
+                        if (self.exitlude_jump_relocs.items.len == 1) {
+                            self.code.items.len -= 5;
+                        } else for (self.exitlude_jump_relocs.items) |jmp_reloc| {
                             const amt = self.code.items.len - (jmp_reloc + 4);
-                            // If it wouldn't jump at all, elide it.
-                            if (amt == 0) {
-                                self.code.items.len -= 5;
-                                continue;
-                            }
                             const s32_amt = @intCast(i32, amt);
                             mem.writeIntLittle(i32, self.code.items[jmp_reloc..][0..4], s32_amt);
                         }