diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2023-10-25 18:39:44 -0700 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2023-11-06 10:43:04 -0800 |
| commit | f245757701ccd2d4f1c9ee0ed349e3a1d8049996 (patch) | |
| tree | 8c628df80b3d49679648cd1dbaa6cec0b10b30c8 /tcg/optimize.c | |
| parent | 6334a968eec3f2498a992a7b96c1bfcaf100066f (diff) | |
tcg/optimize: Canonicalize sub2 with constants to add2
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231026013945.1152174-4-richard.henderson@linaro.org>
Diffstat (limited to 'tcg/optimize.c')
| -rw-r--r-- | tcg/optimize.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/tcg/optimize.c b/tcg/optimize.c index 468f827399..f2d01654c5 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -1044,8 +1044,10 @@ static bool fold_add_vec(OptContext *ctx, TCGOp *op) static bool fold_addsub2(OptContext *ctx, TCGOp *op, bool add) { - if (arg_is_const(op->args[2]) && arg_is_const(op->args[3]) && - arg_is_const(op->args[4]) && arg_is_const(op->args[5])) { + bool a_const = arg_is_const(op->args[2]) && arg_is_const(op->args[3]); + bool b_const = arg_is_const(op->args[4]) && arg_is_const(op->args[5]); + + if (a_const && b_const) { uint64_t al = arg_info(op->args[2])->val; uint64_t ah = arg_info(op->args[3])->val; uint64_t bl = arg_info(op->args[4])->val; @@ -1089,6 +1091,21 @@ static bool fold_addsub2(OptContext *ctx, TCGOp *op, bool add) tcg_opt_gen_movi(ctx, op2, rh, ah); return true; } + + /* Fold sub2 r,x,i to add2 r,x,-i */ + if (!add && b_const) { + uint64_t bl = arg_info(op->args[4])->val; + uint64_t bh = arg_info(op->args[5])->val; + + /* Negate the two parts without assembling and disassembling. */ + bl = -bl; + bh = ~bh + !bl; + + op->opc = (ctx->type == TCG_TYPE_I32 + ? INDEX_op_add2_i32 : INDEX_op_add2_i64); + op->args[4] = arg_new_constant(ctx, bl); + op->args[5] = arg_new_constant(ctx, bh); + } return false; } |