ZJIT: Split Lea memory reads on x86_64

Author: tekknolagi

zjit/src/backend/x86_64/mod.rs

@@ -559,7 +559,8 @@ impl Assembler {
                         asm.store(mem_out, SCRATCH0_OPND);
                     }
                 }
-                Insn::Lea { out, .. } => {
+                Insn::Lea { opnd, out } => {
+                    *opnd = split_stack_membase(asm, *opnd, SCRATCH0_OPND, &stack_state);
                     let mem_out = split_memory_write(out, SCRATCH0_OPND);
                     asm.push_insn(insn);
                     if let Some(mem_out) = mem_out {
@@ -1804,4 +1805,20 @@ mod tests {
         ");
         assert_snapshot!(cb.hexdump(), @"4c8b55f84c8b5df04d8b5b024d0f441a4c895df8");
     }
+
+    #[test]
+    fn test_lea_split_memory_read() {
+        let (mut asm, mut cb) = setup_asm();
+
+        let opnd = Opnd::Mem(Mem { base: MemBase::Stack { stack_idx: 0, num_bits: 64 }, disp: 0, num_bits: 64 });
+        let _ = asm.lea(opnd);
+        asm.compile_with_num_regs(&mut cb, 0);
+
+        assert_disasm_snapshot!(cb.disasm(), @"
+            0x0: mov r11, qword ptr [rbp - 8]
+            0x4: lea r11, [r11]
+            0x7: mov qword ptr [rbp - 8], r11
+        ");
+        assert_snapshot!(cb.hexdump(), @"4c8b5df84d8d1b4c895df8");
+    }
 }