From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:35820) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TJ7Ia-0007qF-5b for qemu-devel@nongnu.org; Tue, 02 Oct 2012 14:34:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TJ7IT-0008A2-Aq for qemu-devel@nongnu.org; Tue, 02 Oct 2012 14:34:28 -0400 Received: from mail-pb0-f45.google.com ([209.85.160.45]:35104) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TJ7IT-0007kE-4A for qemu-devel@nongnu.org; Tue, 02 Oct 2012 14:34:21 -0400 Received: by mail-pb0-f45.google.com with SMTP id rp2so9148949pbb.4 for ; Tue, 02 Oct 2012 11:34:20 -0700 (PDT) Sender: Richard Henderson From: Richard Henderson Date: Tue, 2 Oct 2012 11:32:27 -0700 Message-Id: <1349202750-16815-8-git-send-email-rth@twiddle.net> In-Reply-To: <1349202750-16815-1-git-send-email-rth@twiddle.net> References: <1349202750-16815-1-git-send-email-rth@twiddle.net> Subject: [Qemu-devel] [PATCH 07/10] tcg: Do constant folding on double-word comparisons List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Aurelien Jarno Signed-off-by: Richard Henderson --- tcg/optimize.c | 93 +++++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 72 insertions(+), 21 deletions(-) diff --git a/tcg/optimize.c b/tcg/optimize.c index 38027dc..d9251e4 100644 --- a/tcg/optimize.c +++ b/tcg/optimize.c @@ -398,6 +398,40 @@ static TCGArg do_constant_folding_cond(TCGOpcode op, TCGArg x, } } +/* Return 2 if the condition can't be simplified, and the result + of the condition (0 or 1) if it can */ +static TCGArg do_constant_folding_cond2(TCGArg *p1, TCGArg *p2, TCGCond c) +{ + TCGArg al = p1[0], ah = p1[1]; + TCGArg bl = p2[0], bh = p2[1]; + + if (temps[bl].state == TCG_TEMP_CONST + && temps[bh].state == TCG_TEMP_CONST) { + uint64_t b = ((uint64_t)temps[bh].val << 32) | (uint32_t)temps[bl].val; + + if (temps[al].state == TCG_TEMP_CONST + && temps[ah].state == TCG_TEMP_CONST) { + uint64_t a; + a = ((uint64_t)temps[ah].val << 32) | (uint32_t)temps[al].val; + return do_constant_folding_cond_64(a, b, c); + } + if (b == 0) { + switch (c) { + case TCG_COND_LTU: + return 0; + case TCG_COND_GEU: + return 1; + default: + break; + } + } + } + if (temps_are_copies(al, bl) && temps_are_copies(ah, bh)) { + return do_constant_folding_cond_eq(c); + } + return 2; +} + static bool swap_commutative(TCGArg dest, TCGArg *p1, TCGArg *p2) { TCGArg a1 = *p1, a2 = *p2; @@ -763,43 +797,60 @@ static TCGArg *tcg_constant_folding(TCGContext *s, uint16_t *tcg_opc_ptr, goto do_default; case INDEX_op_brcond2_i32: - /* Simplify LT/GE comparisons vs zero to a single compare - vs the high word of the input. */ - if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE) - && temps[args[2]].state == TCG_TEMP_CONST - && temps[args[3]].state == TCG_TEMP_CONST - && temps[args[2]].val == 0 - && temps[args[3]].val == 0) { + tmp = do_constant_folding_cond2(&args[0], &args[2], args[4]); + if (tmp != 2) { + if (tmp) { + memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info)); + gen_opc_buf[op_index] = INDEX_op_br; + gen_args[0] = args[5]; + gen_args += 1; + } else { + gen_opc_buf[op_index] = INDEX_op_nop; + } + } else if ((args[4] == TCG_COND_LT || args[4] == TCG_COND_GE) + && temps[args[2]].state == TCG_TEMP_CONST + && temps[args[3]].state == TCG_TEMP_CONST + && temps[args[2]].val == 0 + && temps[args[3]].val == 0) { + /* Simplify LT/GE comparisons vs zero to a single compare + vs the high word of the input. */ + memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info)); gen_opc_buf[op_index] = INDEX_op_brcond_i32; gen_args[0] = args[1]; gen_args[1] = args[3]; gen_args[2] = args[4]; gen_args[3] = args[5]; gen_args += 4; - args += 6; - memset(temps, 0, nb_temps * sizeof(struct tcg_temp_info)); - break; + } else { + goto do_default; } - goto do_default; + args += 6; + break; case INDEX_op_setcond2_i32: - /* Simplify LT/GE comparisons vs zero to a single compare - vs the high word of the input. */ - if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE) - && temps[args[3]].state == TCG_TEMP_CONST - && temps[args[4]].state == TCG_TEMP_CONST - && temps[args[3]].val == 0 - && temps[args[4]].val == 0) { + tmp = do_constant_folding_cond2(&args[1], &args[3], args[5]); + if (tmp != 2) { + gen_opc_buf[op_index] = INDEX_op_movi_i32; + tcg_opt_gen_movi(gen_args, args[0], tmp); + gen_args += 2; + } else if ((args[5] == TCG_COND_LT || args[5] == TCG_COND_GE) + && temps[args[3]].state == TCG_TEMP_CONST + && temps[args[4]].state == TCG_TEMP_CONST + && temps[args[3]].val == 0 + && temps[args[4]].val == 0) { + /* Simplify LT/GE comparisons vs zero to a single compare + vs the high word of the input. */ gen_opc_buf[op_index] = INDEX_op_setcond_i32; gen_args[0] = args[0]; gen_args[1] = args[2]; gen_args[2] = args[4]; gen_args[3] = args[5]; gen_args += 4; - args += 6; - break; + } else { + goto do_default; } - goto do_default; + args += 6; + break; case INDEX_op_call: nb_call_args = (args[0] >> 16) + (args[0] & 0xffff); -- 1.7.11.4