add some debugging output

Author: tenderlove

zjit/src/backend/arm64/mod.rs

@@ -893,6 +893,7 @@ impl Assembler {
                 }
                 // Resolve ParallelMov that couldn't be handled without a scratch register.
                 Insn::ParallelMov { moves } => {
+                    panic!();
                     for (dst, src) in Self::resolve_parallel_moves(moves, Some(SCRATCH0_OPND)).unwrap() {
                         let src = split_stack_membase(asm, src, SCRATCH1_OPND, &stack_state);
                         let dst = split_large_disp(asm, dst, SCRATCH2_OPND);
@@ -1642,6 +1643,23 @@ impl Assembler {
 
         let (assignments, num_stack_slots) = asm.linear_scan(intervals.clone(), regs.len());
 
+        // Dump vreg-to-physical-register mapping if requested
+        if let Some(crate::options::Options { dump_lir: Some(dump_lirs), .. }) = unsafe { crate::options::OPTIONS.as_ref() } {
+            if dump_lirs.contains(&crate::options::DumpLIR::alloc_regs) {
+                println!("VReg assignments:");
+                for (i, alloc) in assignments.iter().enumerate() {
+                    if let Some(alloc) = alloc {
+                        let range = &intervals[i].range;
+                        let alloc_str = match alloc {
+                            Allocation::Reg(n) => format!("{}", regs[*n]),
+                            Allocation::Stack(n) => format!("Stack[{}]", n),
+                        };
+                        println!("  v{} => {} (range: {:?}..{:?})", i, alloc_str, range.start, range.end);
+                    }
+                }
+            }
+        }
+
         // Update FrameSetup slot_count to account for spilled VRegs
         if num_stack_slots > 0 {
             for block in asm.basic_blocks.iter_mut() {

zjit/src/backend/lir.rs

@@ -2237,14 +2237,6 @@ impl Assembler
                     })
                     .collect();
 
-                // Append non-register moves. Moves to memory/stack must come before
-                // moves to registers, because a register-destination move may clobber
-                // a source needed by a memory-destination move.
-                imm_moves.sort_by_key(|m| {
-                    if let Insn::Mov { dest: Opnd::Reg(_), .. } = m { 1 } else { 0 }
-                });
-                moves.extend(imm_moves);
-
                 if moves.is_empty() {
                     continue;
                 }