From patchwork Thu Jul 7 12:37:14 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kirill Batuzov X-Patchwork-Id: 103652 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id C79D31007D7 for ; Thu, 7 Jul 2011 22:52:39 +1000 (EST) Received: from localhost ([::1]:55554 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qeo4I-0003S2-1t for incoming@patchwork.ozlabs.org; Thu, 07 Jul 2011 08:52:34 -0400 Received: from eggs.gnu.org ([140.186.70.92]:45517) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qenpn-0000W8-Ut for qemu-devel@nongnu.org; Thu, 07 Jul 2011 08:37:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Qenpg-0005YF-3O for qemu-devel@nongnu.org; Thu, 07 Jul 2011 08:37:35 -0400 Received: from smtp.ispras.ru ([83.149.198.202]:51662) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Qenpf-0005Xl-4t for qemu-devel@nongnu.org; Thu, 07 Jul 2011 08:37:27 -0400 Received: from ispserv.ispras.ru (ispserv.ispras.ru [83.149.198.72]) by smtp.ispras.ru (Postfix) with ESMTP id 920885D407C; Thu, 7 Jul 2011 16:30:31 +0400 (MSD) Received: from bulbul.intra.ispras.ru (winnie.ispras.ru [83.149.198.236]) by ispserv.ispras.ru (Postfix) with ESMTP id 3C2BB3FC50; Thu, 7 Jul 2011 16:37:26 +0400 (MSD) From: Kirill Batuzov To: qemu-devel@nongnu.org Date: Thu, 7 Jul 2011 16:37:14 +0400 Message-Id: X-Mailer: git-send-email 1.7.4.1 In-Reply-To: References: In-Reply-To: References: X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6, seldom 2.4 (older, 4) X-Received-From: 83.149.198.202 Cc: zhur@ispras.ru Subject: [Qemu-devel] [PATCH v3 3/6] Do constant folding for basic arithmetic operations. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Perform actual constant folding for ADD, SUB and MUL operations. Signed-off-by: Kirill Batuzov --- tcg/optimize.c | 125 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 125 insertions(+), 0 deletions(-) diff --git a/tcg/optimize.c b/tcg/optimize.c index f8afe71..42a1bda 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -96,9 +96,15 @@ static int op_bits(int op) { switch (op) { case INDEX_op_mov_i32: + case INDEX_op_add_i32: + case INDEX_op_sub_i32: + case INDEX_op_mul_i32: return 32; #if TCG_TARGET_REG_BITS == 64 case INDEX_op_mov_i64: + case INDEX_op_add_i64: + case INDEX_op_sub_i64: + case INDEX_op_mul_i64: return 64; #endif default: @@ -156,6 +162,52 @@ static void tcg_opt_gen_movi(TCGArg *gen_args, TCGArg dst, TCGArg val, gen_args[1] = val; } +static int op_to_mov(int op) +{ + switch (op_bits(op)) { + case 32: + return INDEX_op_mov_i32; +#if TCG_TARGET_REG_BITS == 64 + case 64: + return INDEX_op_mov_i64; +#endif + default: + fprintf(stderr, "op_to_mov: unexpected return value of " + "function op_bits.\n"); + tcg_abort(); + } +} + +static TCGArg do_constant_folding_2(int op, TCGArg x, TCGArg y) +{ + switch (op) { + CASE_OP_32_64(add): + return x + y; + + CASE_OP_32_64(sub): + return x - y; + + CASE_OP_32_64(mul): + return x * y; + + default: + fprintf(stderr, + "Unrecognized operation %d in do_constant_folding.\n", op); + tcg_abort(); + } +} + +static TCGArg do_constant_folding(int op, TCGArg x, TCGArg y) +{ + TCGArg res = do_constant_folding_2(op, x, y); +#if TCG_TARGET_REG_BITS == 64 + if (op_bits(op) == 32) { + res &= 0xffffffff; + } +#endif + return res; +} + /* Propagate constants and copies, fold constant expressions. */ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, TCGArg *args, TCGOpDef *tcg_op_defs) @@ -163,6 +215,7 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, int i, nb_ops, op_index, op, nb_temps, nb_globals, nb_call_args; const TCGOpDef *def; TCGArg *gen_args; + TCGArg tmp; /* Array VALS has an element for each temp. If this temp holds a constant then its value is kept in VALS' element. If this temp is a copy of other ones then this equivalence class' @@ -189,6 +242,57 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, } } + /* For commutative operations make constant second argument */ + switch (op) { + CASE_OP_32_64(add): + CASE_OP_32_64(mul): + if (temps[args[1]].state == TCG_TEMP_CONST) { + tmp = args[1]; + args[1] = args[2]; + args[2] = tmp; + } + break; + default: + break; + } + + /* Simplify expression if possible. */ + switch (op) { + CASE_OP_32_64(add): + CASE_OP_32_64(sub): + if (temps[args[1]].state == TCG_TEMP_CONST) { + /* Proceed with possible constant folding. */ + break; + } + if (temps[args[2]].state == TCG_TEMP_CONST + && temps[args[2]].val == 0) { + if ((temps[args[0]].state == TCG_TEMP_COPY + && temps[args[0]].val == args[1]) + || args[0] == args[1]) { + args += 3; + gen_opc_buf[op_index] = INDEX_op_nop; + } else { + gen_opc_buf[op_index] = op_to_mov(op); + tcg_opt_gen_mov(gen_args, args[0], args[1], + nb_temps, nb_globals); + gen_args += 2; + args += 3; + } + continue; + } + break; + CASE_OP_32_64(mul): + if ((temps[args[2]].state == TCG_TEMP_CONST + && temps[args[2]].val == 0)) { + gen_opc_buf[op_index] = op_to_movi(op); + tcg_opt_gen_movi(gen_args, args[0], 0, nb_temps, nb_globals); + args += 3; + gen_args += 2; + continue; + } + break; + } + /* Propagate constants through copy operations and do constant folding. Constants will be substituted to arguments by register allocator where needed and possible. Also detect copies. */ @@ -219,6 +323,27 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, gen_args += 2; args += 2; break; + CASE_OP_32_64(add): + CASE_OP_32_64(sub): + CASE_OP_32_64(mul): + if (temps[args[1]].state == TCG_TEMP_CONST + && temps[args[2]].state == TCG_TEMP_CONST) { + gen_opc_buf[op_index] = op_to_movi(op); + tmp = do_constant_folding(op, temps[args[1]].val, + temps[args[2]].val); + tcg_opt_gen_movi(gen_args, args[0], tmp, nb_temps, nb_globals); + gen_args += 2; + args += 3; + break; + } else { + reset_temp(args[0], nb_temps, nb_globals); + gen_args[0] = args[0]; + gen_args[1] = args[1]; + gen_args[2] = args[2]; + gen_args += 3; + args += 3; + break; + } case INDEX_op_call: nb_call_args = (args[0] >> 16) + (args[0] & 0xffff); if (!(args[nb_call_args + 1] & (TCG_CALL_CONST | TCG_CALL_PURE))) {