From 986bb406ad6af93eebd781860c384cc853103827 Mon Sep 17 00:00:00 2001
From: Mike Pall <mike>
Date: Sun, 19 Sep 2021 17:47:11 +0200
Subject: [PATCH] Use IR_HIOP for generalized two-register returns.

Sponsored by OpenResty Inc.
---
 src/lj_asm.c          | 31 ++++++++++++++-----------------
 src/lj_asm_arm.h      | 27 +++++++++++----------------
 src/lj_asm_arm64.h    | 25 +++++++++++++++++++++----
 src/lj_asm_mips.h     | 37 +++++++++++++------------------------
 src/lj_asm_ppc.h      | 29 +++++++++++------------------
 src/lj_asm_x86.h      | 26 +++++++++++---------------
 src/lj_target_arm64.h |  2 ++
 src/lj_target_x86.h   |  3 +--
 8 files changed, 84 insertions(+), 96 deletions(-)

diff --git a/src/lj_asm.c b/src/lj_asm.c
index 1ecbe45e..d377eb4d 100644
--- a/src/lj_asm.c
+++ b/src/lj_asm.c
@@ -818,11 +818,11 @@ static void ra_leftov(ASMState *as, Reg dest, IRRef lref)
 }
 #endif
 
-#if !LJ_64
 /* Force a RID_RETLO/RID_RETHI destination register pair (marked as free). */
 static void ra_destpair(ASMState *as, IRIns *ir)
 {
   Reg destlo = ir->r, desthi = (ir+1)->r;
+  IRIns *irx = (LJ_64 && !irt_is64(ir->t)) ? ir+1 : ir;
   /* First spill unrelated refs blocking the destination registers. */
   if (!rset_test(as->freeset, RID_RETLO) &&
       destlo != RID_RETLO && desthi != RID_RETLO)
@@ -846,29 +846,28 @@ static void ra_destpair(ASMState *as, IRIns *ir)
   /* Check for conflicts and shuffle the registers as needed. */
   if (destlo == RID_RETHI) {
     if (desthi == RID_RETLO) {
-#if LJ_TARGET_X86
-      *--as->mcp = XI_XCHGa + RID_RETHI;
+#if LJ_TARGET_X86ORX64
+      *--as->mcp = REX_64IR(irx, XI_XCHGa + RID_RETHI);
 #else
-      emit_movrr(as, ir, RID_RETHI, RID_TMP);
-      emit_movrr(as, ir, RID_RETLO, RID_RETHI);
-      emit_movrr(as, ir, RID_TMP, RID_RETLO);
+      emit_movrr(as, irx, RID_RETHI, RID_TMP);
+      emit_movrr(as, irx, RID_RETLO, RID_RETHI);
+      emit_movrr(as, irx, RID_TMP, RID_RETLO);
 #endif
     } else {
-      emit_movrr(as, ir, RID_RETHI, RID_RETLO);
-      if (desthi != RID_RETHI) emit_movrr(as, ir, desthi, RID_RETHI);
+      emit_movrr(as, irx, RID_RETHI, RID_RETLO);
+      if (desthi != RID_RETHI) emit_movrr(as, irx, desthi, RID_RETHI);
     }
   } else if (desthi == RID_RETLO) {
-    emit_movrr(as, ir, RID_RETLO, RID_RETHI);
-    if (destlo != RID_RETLO) emit_movrr(as, ir, destlo, RID_RETLO);
+    emit_movrr(as, irx, RID_RETLO, RID_RETHI);
+    if (destlo != RID_RETLO) emit_movrr(as, irx, destlo, RID_RETLO);
   } else {
-    if (desthi != RID_RETHI) emit_movrr(as, ir, desthi, RID_RETHI);
-    if (destlo != RID_RETLO) emit_movrr(as, ir, destlo, RID_RETLO);
+    if (desthi != RID_RETHI) emit_movrr(as, irx, desthi, RID_RETHI);
+    if (destlo != RID_RETLO) emit_movrr(as, irx, destlo, RID_RETLO);
   }
   /* Restore spill slots (if any). */
   if (ra_hasspill((ir+1)->s)) ra_save(as, ir+1, RID_RETHI);
   if (ra_hasspill(ir->s)) ra_save(as, ir, RID_RETLO);
 }
-#endif
 
 /* -- Snapshot handling --------- ----------------------------------------- */
 
@@ -2234,7 +2233,6 @@ static void asm_setup_regsp(ASMState *as)
 		      (RSET_SCRATCH & ~RSET_FPR) : RSET_SCRATCH;
       continue;
       }
-#if LJ_SOFTFP || (LJ_32 && LJ_HASFFI)
     case IR_HIOP:
       switch ((ir-1)->o) {
 #if LJ_SOFTFP && LJ_TARGET_ARM
@@ -2245,7 +2243,7 @@ static void asm_setup_regsp(ASMState *as)
 	}
 	break;
 #endif
-#if !LJ_SOFTFP && LJ_NEED_FP64
+#if !LJ_SOFTFP && LJ_NEED_FP64 && LJ_32 && LJ_HASFFI
       case IR_CONV:
 	if (irt_isfp((ir-1)->t)) {
 	  ir->prev = REGSP_HINT(RID_FPRET);
@@ -2253,7 +2251,7 @@ static void asm_setup_regsp(ASMState *as)
 	}
 #endif
       /* fallthrough */
-      case IR_CALLN: case IR_CALLXS:
+      case IR_CALLN: case IR_CALLL: case IR_CALLS: case IR_CALLXS:
 #if LJ_SOFTFP
       case IR_MIN: case IR_MAX:
 #endif
@@ -2264,7 +2262,6 @@ static void asm_setup_regsp(ASMState *as)
 	break;
       }
       break;
-#endif
 #if LJ_SOFTFP
     case IR_MIN: case IR_MAX:
       if ((ir+1)->o != IR_HIOP) break;
diff --git a/src/lj_asm_arm.h b/src/lj_asm_arm.h
index 3adb534b..e53f9b08 100644
--- a/src/lj_asm_arm.h
+++ b/src/lj_asm_arm.h
@@ -1885,15 +1885,15 @@ static void asm_int64comp(ASMState *as, IRIns *ir)
 }
 #endif
 
-/* -- Support for 64 bit ops in 32 bit mode ------------------------------- */
+/* -- Split register ops -------------------------------------------------- */
 
-/* Hiword op of a split 64 bit op. Previous op must be the loword op. */
+/* Hiword op of a split 32/32 bit op. Previous op is the loword op. */
 static void asm_hiop(ASMState *as, IRIns *ir)
 {
-#if LJ_HASFFI || LJ_SOFTFP
   /* HIOP is marked as a store because it needs its own DCE logic. */
   int uselo = ra_used(ir-1), usehi = ra_used(ir);  /* Loword/hiword used? */
   if (LJ_UNLIKELY(!(as->flags & JIT_F_OPT_DCE))) uselo = usehi = 1;
+#if LJ_HASFFI || LJ_SOFTFP
   if ((ir-1)->o <= IR_NE) {  /* 64 bit integer or FP comparisons. ORDER IR. */
     as->curins--;  /* Always skip the loword comparison. */
 #if LJ_SOFTFP
@@ -1924,6 +1924,7 @@ static void asm_hiop(ASMState *as, IRIns *ir)
       asm_xstore_(as, ir, 4);
     return;
   }
+#endif
   if (!usehi) return;  /* Skip unused hiword op for all remaining ops. */
   switch ((ir-1)->o) {
 #if LJ_HASFFI
@@ -1942,6 +1943,9 @@ static void asm_hiop(ASMState *as, IRIns *ir)
     asm_intneg(as, ir, ARMI_RSC);
     asm_intneg(as, ir-1, ARMI_RSB|ARMI_S);
     break;
+  case IR_CNEWI:
+    /* Nothing to do here. Handled by lo op itself. */
+    break;
 #endif
 #if LJ_SOFTFP
   case IR_SLOAD: case IR_ALOAD: case IR_HLOAD: case IR_ULOAD: case IR_VLOAD:
@@ -1949,25 +1953,16 @@ static void asm_hiop(ASMState *as, IRIns *ir)
     if (!uselo)
       ra_allocref(as, ir->op1, RSET_GPR);  /* Mark lo op as used. */
     break;
+  case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_TOSTR: case IR_TMPREF:
+    /* Nothing to do here. Handled by lo op itself. */
+    break;
 #endif
-  case IR_CALLN:
-  case IR_CALLS:
-  case IR_CALLXS:
+  case IR_CALLN: case IR_CALLL: case IR_CALLS: case IR_CALLXS:
     if (!uselo)
       ra_allocref(as, ir->op1, RID2RSET(RID_RETLO));  /* Mark lo op as used. */
     break;
-#if LJ_SOFTFP
-  case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_TOSTR: case IR_TMPREF:
-#endif
-  case IR_CNEWI:
-    /* Nothing to do here. Handled by lo op itself. */
-    break;
   default: lj_assertA(0, "bad HIOP for op %d", (ir-1)->o); break;
   }
-#else
-  /* Unused without SOFTFP or FFI. */
-  UNUSED(as); UNUSED(ir); lj_assertA(0, "unexpected HIOP");
-#endif
 }
 
 /* -- Profiling ----------------------------------------------------------- */
diff --git a/src/lj_asm_arm64.h b/src/lj_asm_arm64.h
index f51c6f76..3cedd021 100644
--- a/src/lj_asm_arm64.h
+++ b/src/lj_asm_arm64.h
@@ -460,8 +460,11 @@ static void asm_gencall(ASMState *as, const CCallInfo *ci, IRRef *args)
 static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
 {
   RegSet drop = RSET_SCRATCH;
+  int hiop = ((ir+1)->o == IR_HIOP && !irt_isnil((ir+1)->t));
   if (ra_hasreg(ir->r))
     rset_clear(drop, ir->r); /* Dest reg handled below. */
+  if (hiop && ra_hasreg((ir+1)->r))
+    rset_clear(drop, (ir+1)->r);  /* Dest reg handled below. */
   ra_evictset(as, drop); /* Evictions must be performed first. */
   if (ra_used(ir)) {
     lj_assertA(!irt_ispri(ir->t), "PRI dest");
@@ -473,6 +476,8 @@ static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
       } else {
 	ra_destreg(as, ir, RID_FPRET);
       }
+    } else if (hiop) {
+      ra_destpair(as, ir);
     } else {
       ra_destreg(as, ir, RID_RET);
     }
@@ -1720,13 +1725,25 @@ static void asm_comp(ASMState *as, IRIns *ir)
 
 #define asm_equal(as, ir)	asm_comp(as, ir)
 
-/* -- Support for 64 bit ops in 32 bit mode ------------------------------- */
+/* -- Split register ops -------------------------------------------------- */
 
-/* Hiword op of a split 64 bit op. Previous op must be the loword op. */
+/* Hiword op of a split 64/64 bit op. Previous op is the loword op. */
 static void asm_hiop(ASMState *as, IRIns *ir)
 {
-  UNUSED(as); UNUSED(ir);
-  lj_assertA(0, "unexpected HIOP");  /* Unused on 64 bit. */
+  /* HIOP is marked as a store because it needs its own DCE logic. */
+  int uselo = ra_used(ir-1), usehi = ra_used(ir);  /* Loword/hiword used? */
+  if (LJ_UNLIKELY(!(as->flags & JIT_F_OPT_DCE))) uselo = usehi = 1;
+  if (!usehi) return;  /* Skip unused hiword op for all remaining ops. */
+  switch ((ir-1)->o) {
+  case IR_CALLN:
+  case IR_CALLL:
+  case IR_CALLS:
+  case IR_CALLXS:
+    if (!uselo)
+      ra_allocref(as, ir->op1, RID2RSET(RID_RETLO));  /* Mark lo op as used. */
+    break;
+  default: lj_assertA(0, "bad HIOP for op %d", (ir-1)->o); break;
+  }
 }
 
 /* -- Profiling ----------------------------------------------------------- */
diff --git a/src/lj_asm_mips.h b/src/lj_asm_mips.h
index cd32d038..7f7dc6a0 100644
--- a/src/lj_asm_mips.h
+++ b/src/lj_asm_mips.h
@@ -351,19 +351,15 @@ static void asm_gencall(ASMState *as, const CCallInfo *ci, IRRef *args)
 static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
 {
   RegSet drop = RSET_SCRATCH;
-#if LJ_32
   int hiop = ((ir+1)->o == IR_HIOP && !irt_isnil((ir+1)->t));
-#endif
 #if !LJ_SOFTFP
   if ((ci->flags & CCI_NOFPRCLOBBER))
     drop &= ~RSET_FPR;
 #endif
   if (ra_hasreg(ir->r))
     rset_clear(drop, ir->r);  /* Dest reg handled below. */
-#if LJ_32
   if (hiop && ra_hasreg((ir+1)->r))
     rset_clear(drop, (ir+1)->r);  /* Dest reg handled below. */
-#endif
   ra_evictset(as, drop);  /* Evictions must be performed first. */
   if (ra_used(ir)) {
     lj_assertA(!irt_ispri(ir->t), "PRI dest");
@@ -392,10 +388,8 @@ static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
       } else {
 	ra_destreg(as, ir, RID_FPRET);
       }
-#if LJ_32
     } else if (hiop) {
       ra_destpair(as, ir);
-#endif
     } else {
       ra_destreg(as, ir, RID_RET);
     }
@@ -2393,15 +2387,15 @@ static void asm_comp64eq(ASMState *as, IRIns *ir)
 }
 #endif
 
-/* -- Support for 64 bit ops in 32 bit mode ------------------------------- */
+/* -- Split register ops -------------------------------------------------- */
 
-/* Hiword op of a split 64 bit op. Previous op must be the loword op. */
+/* Hiword op of a split 32/32 or 64/64 bit op. Previous op is the loword op. */
 static void asm_hiop(ASMState *as, IRIns *ir)
 {
-#if LJ_32 && (LJ_HASFFI || LJ_SOFTFP)
   /* HIOP is marked as a store because it needs its own DCE logic. */
   int uselo = ra_used(ir-1), usehi = ra_used(ir);  /* Loword/hiword used? */
   if (LJ_UNLIKELY(!(as->flags & JIT_F_OPT_DCE))) uselo = usehi = 1;
+#if LJ_32 && (LJ_HASFFI || LJ_SOFTFP)
   if ((ir-1)->o == IR_CONV) {  /* Conversions to/from 64 bit. */
     as->curins--;  /* Always skip the CONV. */
 #if LJ_HASFFI && !LJ_SOFTFP
@@ -2448,38 +2442,33 @@ static void asm_hiop(ASMState *as, IRIns *ir)
     }
     return;
   }
+#endif
   if (!usehi) return;  /* Skip unused hiword op for all remaining ops. */
   switch ((ir-1)->o) {
-#if LJ_HASFFI
+#if LJ_32 && LJ_HASFFI
   case IR_ADD: as->curins--; asm_add64(as, ir); break;
   case IR_SUB: as->curins--; asm_sub64(as, ir); break;
   case IR_NEG: as->curins--; asm_neg64(as, ir); break;
+  case IR_CNEWI:
+    /* Nothing to do here. Handled by lo op itself. */
+    break;
 #endif
-#if LJ_SOFTFP
+#if LJ_32 && LJ_SOFTFP
   case IR_SLOAD: case IR_ALOAD: case IR_HLOAD: case IR_ULOAD: case IR_VLOAD:
   case IR_STRTO:
     if (!uselo)
       ra_allocref(as, ir->op1, RSET_GPR);  /* Mark lo op as used. */
     break;
+  case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_TOSTR: case IR_TMPREF:
+    /* Nothing to do here. Handled by lo op itself. */
+    break;
 #endif
-  case IR_CALLN:
-  case IR_CALLS:
-  case IR_CALLXS:
+  case IR_CALLN: case IR_CALLL: case IR_CALLS: case IR_CALLXS:
     if (!uselo)
       ra_allocref(as, ir->op1, RID2RSET(RID_RETLO));  /* Mark lo op as used. */
     break;
-#if LJ_SOFTFP
-  case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_TOSTR: case IR_TMPREF:
-#endif
-  case IR_CNEWI:
-    /* Nothing to do here. Handled by lo op itself. */
-    break;
   default: lj_assertA(0, "bad HIOP for op %d", (ir-1)->o); break;
   }
-#else
-  /* Unused on MIPS64 or without SOFTFP or FFI. */
-  UNUSED(as); UNUSED(ir); lj_assertA(0, "unexpected HIOP");
-#endif
 }
 
 /* -- Profiling ----------------------------------------------------------- */
diff --git a/src/lj_asm_ppc.h b/src/lj_asm_ppc.h
index ba60b7e6..f99561b3 100644
--- a/src/lj_asm_ppc.h
+++ b/src/lj_asm_ppc.h
@@ -340,10 +340,8 @@ static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
       } else {
 	ra_destreg(as, ir, RID_FPRET);
       }
-#if LJ_32
     } else if (hiop) {
       ra_destpair(as, ir);
-#endif
     } else {
       ra_destreg(as, ir, RID_RET);
     }
@@ -1942,15 +1940,15 @@ static void asm_comp64(ASMState *as, IRIns *ir)
 }
 #endif
 
-/* -- Support for 64 bit ops in 32 bit mode ------------------------------- */
+/* -- Split register ops -------------------------------------------------- */
 
-/* Hiword op of a split 64 bit op. Previous op must be the loword op. */
+/* Hiword op of a split 32/32 bit op. Previous op is be the loword op. */
 static void asm_hiop(ASMState *as, IRIns *ir)
 {
-#if LJ_HASFFI || LJ_SOFTFP
   /* HIOP is marked as a store because it needs its own DCE logic. */
   int uselo = ra_used(ir-1), usehi = ra_used(ir);  /* Loword/hiword used? */
   if (LJ_UNLIKELY(!(as->flags & JIT_F_OPT_DCE))) uselo = usehi = 1;
+#if LJ_HASFFI || LJ_SOFTFP
   if ((ir-1)->o == IR_CONV) {  /* Conversions to/from 64 bit. */
     as->curins--;  /* Always skip the CONV. */
 #if LJ_HASFFI && !LJ_SOFTFP
@@ -1985,12 +1983,16 @@ static void asm_hiop(ASMState *as, IRIns *ir)
     }
     return;
   }
+#endif
   if (!usehi) return;  /* Skip unused hiword op for all remaining ops. */
   switch ((ir-1)->o) {
 #if LJ_HASFFI
   case IR_ADD: as->curins--; asm_add64(as, ir); break;
   case IR_SUB: as->curins--; asm_sub64(as, ir); break;
   case IR_NEG: as->curins--; asm_neg64(as, ir); break;
+  case IR_CNEWI:
+    /* Nothing to do here. Handled by lo op itself. */
+    break;
 #endif
 #if LJ_SOFTFP
   case IR_SLOAD: case IR_ALOAD: case IR_HLOAD: case IR_ULOAD: case IR_VLOAD:
@@ -1998,25 +2000,16 @@ static void asm_hiop(ASMState *as, IRIns *ir)
     if (!uselo)
       ra_allocref(as, ir->op1, RSET_GPR);  /* Mark lo op as used. */
     break;
+  case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_TOSTR: case IR_TMPREF:
+    /* Nothing to do here. Handled by lo op itself. */
+    break;
 #endif
-  case IR_CALLN:
-  case IR_CALLS:
-  case IR_CALLXS:
+  case IR_CALLN: case IR_CALLL: case IR_CALLS: case IR_CALLXS:
     if (!uselo)
       ra_allocref(as, ir->op1, RID2RSET(RID_RETLO));  /* Mark lo op as used. */
     break;
-#if LJ_SOFTFP
-  case IR_ASTORE: case IR_HSTORE: case IR_USTORE: case IR_TOSTR: case IR_TMPREF:
-#endif
-  case IR_CNEWI:
-    /* Nothing to do here. Handled by lo op itself. */
-    break;
   default: lj_assertA(0, "bad HIOP for op %d", (ir-1)->o); break;
   }
-#else
-  /* Unused without SOFTFP or FFI. */
-  UNUSED(as); UNUSED(ir); lj_assertA(0, "unexpected HIOP");
-#endif
 }
 
 /* -- Profiling ----------------------------------------------------------- */
diff --git a/src/lj_asm_x86.h b/src/lj_asm_x86.h
index 512f1afd..48c31fe3 100644
--- a/src/lj_asm_x86.h
+++ b/src/lj_asm_x86.h
@@ -659,7 +659,7 @@ static void asm_gencall(ASMState *as, const CCallInfo *ci, IRRef *args)
 static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
 {
   RegSet drop = RSET_SCRATCH;
-  int hiop = (LJ_32 && (ir+1)->o == IR_HIOP && !irt_isnil((ir+1)->t));
+  int hiop = ((ir+1)->o == IR_HIOP && !irt_isnil((ir+1)->t));
   if ((ci->flags & CCI_NOFPRCLOBBER))
     drop &= ~RSET_FPR;
   if (ra_hasreg(ir->r))
@@ -699,10 +699,8 @@ static void asm_setupresult(ASMState *as, IRIns *ir, const CCallInfo *ci)
 		  irt_isnum(ir->t) ? XOg_FSTPq : XOg_FSTPd, RID_ESP, ofs);
       }
 #endif
-#if LJ_32
     } else if (hiop) {
       ra_destpair(as, ir);
-#endif
     } else {
       lj_assertA(!irt_ispri(ir->t), "PRI dest");
       ra_destreg(as, ir, RID_RET);
@@ -2611,15 +2609,15 @@ static void asm_comp_int64(ASMState *as, IRIns *ir)
 }
 #endif
 
-/* -- Support for 64 bit ops in 32 bit mode ------------------------------- */
+/* -- Split register ops -------------------------------------------------- */
 
-/* Hiword op of a split 64 bit op. Previous op must be the loword op. */
+/* Hiword op of a split 32/32 or 64/64 bit op. Previous op is the loword op. */
 static void asm_hiop(ASMState *as, IRIns *ir)
 {
-#if LJ_32 && LJ_HASFFI
   /* HIOP is marked as a store because it needs its own DCE logic. */
   int uselo = ra_used(ir-1), usehi = ra_used(ir);  /* Loword/hiword used? */
   if (LJ_UNLIKELY(!(as->flags & JIT_F_OPT_DCE))) uselo = usehi = 1;
+#if LJ_32 && LJ_HASFFI
   if ((ir-1)->o == IR_CONV) {  /* Conversions to/from 64 bit. */
     as->curins--;  /* Always skip the CONV. */
     if (usehi || uselo)
@@ -2633,8 +2631,10 @@ static void asm_hiop(ASMState *as, IRIns *ir)
       asm_fxstore(as, ir);
     return;
   }
+#endif
   if (!usehi) return;  /* Skip unused hiword op for all remaining ops. */
   switch ((ir-1)->o) {
+#if LJ_32 && LJ_HASFFI
   case IR_ADD:
     as->flagmcp = NULL;
     as->curins--;
@@ -2657,20 +2657,16 @@ static void asm_hiop(ASMState *as, IRIns *ir)
     asm_neg_not(as, ir-1, XOg_NEG);
     break;
     }
-  case IR_CALLN:
-  case IR_CALLXS:
-    if (!uselo)
-      ra_allocref(as, ir->op1, RID2RSET(RID_RETLO));  /* Mark lo op as used. */
-    break;
   case IR_CNEWI:
     /* Nothing to do here. Handled by CNEWI itself. */
     break;
+#endif
+  case IR_CALLN: case IR_CALLL: case IR_CALLS: case IR_CALLXS:
+    if (!uselo)
+      ra_allocref(as, ir->op1, RID2RSET(RID_RETLO));  /* Mark lo op as used. */
+    break;
   default: lj_assertA(0, "bad HIOP for op %d", (ir-1)->o); break;
   }
-#else
-  /* Unused on x64 or without FFI. */
-  UNUSED(as); UNUSED(ir); lj_assertA(0, "unexpected HIOP");
-#endif
 }
 
 /* -- Profiling ----------------------------------------------------------- */
diff --git a/src/lj_target_arm64.h b/src/lj_target_arm64.h
index bf568a8d..6d39ffb8 100644
--- a/src/lj_target_arm64.h
+++ b/src/lj_target_arm64.h
@@ -31,6 +31,8 @@ enum {
 
   /* Calling conventions. */
   RID_RET = RID_X0,
+  RID_RETLO = RID_X0,
+  RID_RETHI = RID_X1,
   RID_FPRET = RID_D0,
 
   /* These definitions must match with the *.dasc file(s): */
diff --git a/src/lj_target_x86.h b/src/lj_target_x86.h
index a403f820..d0ce196c 100644
--- a/src/lj_target_x86.h
+++ b/src/lj_target_x86.h
@@ -38,10 +38,9 @@ enum {
   RID_RET = RID_EAX,
 #if LJ_64
   RID_FPRET = RID_XMM0,
-#else
+#endif
   RID_RETLO = RID_EAX,
   RID_RETHI = RID_EDX,
-#endif
 
   /* These definitions must match with the *.dasc file(s): */
   RID_BASE = RID_EDX,		/* Interpreter BASE. */