ZJIT: Remove redundant unboxing

Author: nozomemein

zjit/src/hir.rs

@@ -6545,10 +6545,9 @@ pub fn iseq_to_hir(iseq: *const rb_iseq_t) -> Result<Function, ParseError> {
                     let length = fun.push_insn(block, Insn::ArrayLength { array });
                     fun.push_insn(block, Insn::GuardBitEquals { val: length, expected: Const::CInt64(num as i64), reason: SideExitReason::ExpandArray, state: exit_id });
                     for i in (0..num).rev() {
-                        let index = fun.push_insn(block, Insn::Const { val: Const::Value(VALUE::fixnum_from_usize(i.try_into().unwrap())) });
                         // We do not emit a length guard here because in-bounds is already
                         // ensured by the expandarray length check above.
-                        let index = fun.push_insn(block, Insn::UnboxFixnum { val: index });
+                        let index = fun.push_insn(block, Insn::Const { val: Const::CInt64(i.try_into().unwrap()) });
                         let element = fun.push_insn(block, Insn::ArrayAref { array, index });
                         state.stack_push(element);
                     }

zjit/src/hir/tests.rs

@@ -3565,12 +3565,10 @@ pub mod hir_build_tests {
           v21:ArrayExact = GuardType v13, ArrayExact
           v22:CInt64 = ArrayLength v21
           v23:CInt64[2] = GuardBitEquals v22, CInt64(2)
-          v24:Fixnum[1] = Const Value(1)
-          v25:CInt64[1] = UnboxFixnum v24
-          v26:BasicObject = ArrayAref v21, v25
-          v27:Fixnum[0] = Const Value(0)
-          v28:CInt64[0] = UnboxFixnum v27
-          v29:BasicObject = ArrayAref v21, v28
+          v24:CInt64[1] = Const CInt64(1)
+          v25:BasicObject = ArrayAref v21, v24
+          v26:CInt64[0] = Const CInt64(0)
+          v27:BasicObject = ArrayAref v21, v26
           PatchPoint NoEPEscape(test)
           CheckInterrupts
           Return v13