From 6334a968eec3f2498a992a7b96c1bfcaf100066f Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 25 Oct 2023 18:39:43 -0700 Subject: [PATCH] tcg/optimize: Canonicalize subi to addi during optimization MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20231026013945.1152174-3-richard.henderson@linaro.org> --- tcg/optimize.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/tcg/optimize.c b/tcg/optimize.c index d8e437c826..468f827399 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -2166,7 +2166,19 @@ static bool fold_sub_vec(OptContext *ctx, TCGOp *op) static bool fold_sub(OptContext *ctx, TCGOp *op) { - return fold_const2(ctx, op) || fold_sub_vec(ctx, op); + if (fold_const2(ctx, op) || fold_sub_vec(ctx, op)) { + return true; + } + + /* Fold sub r,x,i to add r,x,-i */ + if (arg_is_const(op->args[2])) { + uint64_t val = arg_info(op->args[2])->val; + + op->opc = (ctx->type == TCG_TYPE_I32 + ? INDEX_op_add_i32 : INDEX_op_add_i64); + op->args[2] = arg_new_constant(ctx, -val); + } + return false; } static bool fold_sub2(OptContext *ctx, TCGOp *op)