ARM: Unify rotates to simplify assembler backend.

3 files changed, 13 insertions, 2 deletions

diff --git a/src/lj_arch.h b/src/lj_arch.h
index 978ccd1f..a234a400 100644
--- a/src/lj_arch.h
+++ b/src/lj_arch.h
@@ -137,6 +137,7 @@
 #define LJ_TARGET_JUMPRANGE     25      /* +-2^25 = +-32MB */
 #define LJ_TARGET_MASKSHIFT     0
 #define LJ_TARGET_MASKROT       1
+#define LJ_TARGET_UNIFYROT      2       /* Want only IR_BROR. */
 #define LJ_ARCH_DUALNUM         2
 #define LJ_ARCH_NOJIT           1
 
@@ -158,6 +159,7 @@
 #define LJ_TARGET_JUMPRANGE     25      /* +-2^25 = +-32MB */
 #define LJ_TARGET_MASKSHIFT     0
 #define LJ_TARGET_MASKROT       1
+#define LJ_TARGET_UNIFYROT      1       /* Want only IR_BROL. */
 #define LJ_ARCH_DUALNUM         0
 #define LJ_ARCH_NOFFI           1       /* NYI: comparisons, calls. */
 #define LJ_ARCH_NOJIT           1
diff --git a/src/lj_ffrecord.c b/src/lj_ffrecord.c
index 0de54f04..8cc42406 100644
--- a/src/lj_ffrecord.c
+++ b/src/lj_ffrecord.c
@@ -570,10 +570,17 @@ static void LJ_FASTCALL recff_bit_shift(jit_State *J, RecordFFData *rd)
 {
   TRef tr = lj_opt_narrow_tobit(J, J->base[0]);
   TRef tsh = lj_opt_narrow_tobit(J, J->base[1]);
-  if (!(rd->data < IR_BROL ? LJ_TARGET_MASKSHIFT : LJ_TARGET_MASKROT) &&
+  IROp op = (IROp)rd->data;
+  if (!(op < IR_BROL ? LJ_TARGET_MASKSHIFT : LJ_TARGET_MASKROT) &&
       !tref_isk(tsh))
     tsh = emitir(IRTI(IR_BAND), tsh, lj_ir_kint(J, 31));
-  J->base[0] = emitir(IRTI(rd->data), tr, tsh);
+#ifdef LJ_TARGET_UNIFYROT
+  if (op == (LJ_TARGET_UNIFYROT == 1 ? IR_BROR : IR_BROL)) {
+    op = LJ_TARGET_UNIFYROT == 1 ? IR_BROL : IR_BROR;
+    tsh = emitir(IRTI(IR_NEG), tsh, tsh);
+  }
+#endif
+  J->base[0] = emitir(IRTI(op), tr, tsh);
 }
 
 /* -- String library fast functions --------------------------------------- */
diff --git a/src/lj_opt_fold.c b/src/lj_opt_fold.c
index c8b4edfe..2e61abe4 100644
--- a/src/lj_opt_fold.c
+++ b/src/lj_opt_fold.c
@@ -1303,11 +1303,13 @@ LJFOLDF(simplify_shift_ik)
     fins->op2 = (IRRef1)lj_ir_kint(J, k);
     return RETRYFOLD;
   }
+#ifndef LJ_TARGET_UNIFYROT
   if (fins->o == IR_BROR) {  /* bror(i, k) ==> brol(i, (-k)&mask) */
     fins->o = IR_BROL;
     fins->op2 = (IRRef1)lj_ir_kint(J, (-k)&mask);
     return RETRYFOLD;
   }
+#endif
   return NEXTFOLD;
 }