From: Paolo Bonzini <pbonzini@redhat.com>

Create a function to test whether the second operand of a
binary operation allows a given immediate.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[rth: Split out from a larger patch; keep the declaration internal.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/tcg-internal.h |  5 +++++
 tcg/tcg.c          | 21 +++++++++++++++++----
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/tcg/tcg-internal.h b/tcg/tcg-internal.h
index 2cbfb5d5ca..c1ce50998e 100644
--- a/tcg/tcg-internal.h
+++ b/tcg/tcg-internal.h
@@ -94,4 +94,9 @@ TCGOp *tcg_op_insert_before(TCGContext *s, TCGOp *op,
 TCGOp *tcg_op_insert_after(TCGContext *s, TCGOp *op,
                            TCGOpcode, TCGType, unsigned nargs);
 
+/*
+ * For a binary opcode OP, return true if the second input operand allows IMM.
+ */
+bool tcg_op_imm_match(TCGOpcode op, TCGType type, tcg_target_ulong imm);
+
 #endif /* TCG_INTERNAL_H */
diff --git a/tcg/tcg.c b/tcg/tcg.c
index e7bf4dad4e..778268f5cd 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -3391,11 +3391,9 @@ static void process_constraint_sets(void)
     }
 }
 
-static const TCGArgConstraint *opcode_args_ct(const TCGOp *op)
+static const TCGArgConstraint *op_args_ct(TCGOpcode opc, TCGType type,
+                                          unsigned flags)
 {
-    TCGOpcode opc = op->opc;
-    TCGType type = TCGOP_TYPE(op);
-    unsigned flags = TCGOP_FLAGS(op);
     const TCGOpDef *def = &tcg_op_defs[opc];
     const TCGOutOp *outop = all_outop[opc];
     TCGConstraintSetIndex con_set;
@@ -3422,6 +3420,21 @@ static const TCGArgConstraint *opcode_args_ct(const TCGOp *op)
     return all_cts[con_set];
 }
 
+static const TCGArgConstraint *opcode_args_ct(const TCGOp *op)
+{
+    return op_args_ct(op->opc, TCGOP_TYPE(op), TCGOP_FLAGS(op));
+}
+
+bool tcg_op_imm_match(TCGOpcode opc, TCGType type, tcg_target_ulong imm)
+{
+    const TCGArgConstraint *args_ct = op_args_ct(opc, type, 0);
+    const TCGOpDef *def = &tcg_op_defs[opc];
+
+    tcg_debug_assert(def->nb_oargs == 1);
+    tcg_debug_assert(def->nb_iargs == 2);
+    return tcg_target_const_match(imm, args_ct[2].ct, type, 0, 0);
+}
+
 static void remove_label_use(TCGOp *op, int idx)
 {
     TCGLabel *label = arg_label(op->args[idx]);
-- 
2.43.0