From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47361) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ay3Cr-0003iM-Mn for qemu-devel@nongnu.org; Wed, 04 May 2016 16:15:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ay3Cf-0004KJ-Tn for qemu-devel@nongnu.org; Wed, 04 May 2016 16:15:32 -0400 Received: from smtp1-g21.free.fr ([212.27.42.1]:33638) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ay3Cf-00043P-9F for qemu-devel@nongnu.org; Wed, 04 May 2016 16:15:25 -0400 From: Laurent Vivier Date: Wed, 4 May 2016 22:12:04 +0200 Message-Id: <1462392752-17703-25-git-send-email-laurent@vivier.eu> In-Reply-To: <1462392752-17703-1-git-send-email-laurent@vivier.eu> References: <1462392752-17703-1-git-send-email-laurent@vivier.eu> Subject: [Qemu-devel] [PATCH 24/52] target-m68k: Optimize some comparisons List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: gerg@uclinux.org, schwab@linux-m68k.org, agraf@suse.de, rth@twiddle.net, Laurent Vivier From: Richard Henderson Signed-off-by: Richard Henderson Signed-off-by: Laurent Vivier --- target-m68k/translate.c | 108 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 102 insertions(+), 6 deletions(-) diff --git a/target-m68k/translate.c b/target-m68k/translate.c index 332c34f..cc8a000 100644 --- a/target-m68k/translate.c +++ b/target-m68k/translate.c @@ -768,10 +768,43 @@ static void gen_cc_cond(DisasCompare *c, DisasContext *s, int cond) { TCGv tmp, tmp2; TCGCond tcond; + CCOp op = s->cc_op; - /* TODO: Optimize compare/branch pairs rather than always flushing - flag state to CC_OP_FLAGS. */ - gen_flush_flags(s); + /* The CC_OP_CMP form can handle most normal comparisons directly. */ + if (op == CC_OP_CMP) { + c->g1 = c->g2 = 1; + c->v1 = QREG_CC_N; + c->v2 = QREG_CC_V; + switch (cond) { + case 2: /* HI */ + case 3: /* LS */ + tcond = TCG_COND_LEU; + goto done; + case 4: /* CC */ + case 5: /* CS */ + tcond = TCG_COND_LTU; + goto done; + case 6: /* NE */ + case 7: /* EQ */ + tcond = TCG_COND_EQ; + goto done; + case 10: /* PL */ + case 11: /* MI */ + c->g1 = c->g2 = 0; + c->v2 = tcg_const_i32(0); + c->v1 = tmp = tcg_temp_new(); + tcg_gen_sub_i32(tmp, QREG_CC_N, QREG_CC_V); + /* fallthru */ + case 12: /* GE */ + case 13: /* LT */ + tcond = TCG_COND_LT; + goto done; + case 14: /* GT */ + case 15: /* LE */ + tcond = TCG_COND_LE; + goto done; + } + } c->g1 = 1; c->g2 = 0; @@ -782,7 +815,71 @@ static void gen_cc_cond(DisasCompare *c, DisasContext *s, int cond) case 1: /* F */ c->v1 = c->v2; tcond = TCG_COND_NEVER; + goto done; + case 14: /* GT (!(Z || (N ^ V))) */ + case 15: /* LE (Z || (N ^ V)) */ + /* Logic operations clear V, which simplifies LE to (Z || N), + and since Z and N are co-located, this becomes a normal + comparison vs N. */ + if (op == CC_OP_LOGIC) { + c->v1 = QREG_CC_N; + tcond = TCG_COND_LE; + goto done; + } + break; + case 12: /* GE (!(N ^ V)) */ + case 13: /* LT (N ^ V) */ + /* Logic operations clear V, which simplifies this to N. */ + if (op != CC_OP_LOGIC) { + break; + } + /* fallthru */ + case 10: /* PL (!N) */ + case 11: /* MI (N) */ + /* Several cases represent N normally. */ + if (op == CC_OP_ADD || op == CC_OP_SUB || op == CC_OP_LOGIC) { + c->v1 = QREG_CC_N; + tcond = TCG_COND_LT; + goto done; + } + break; + case 6: /* NE (!Z) */ + case 7: /* EQ (Z) */ + /* Some cases fold Z into N. */ + if (op == CC_OP_ADD || op == CC_OP_SUB || op == CC_OP_LOGIC) { + tcond = TCG_COND_EQ; + c->v1 = QREG_CC_N; + goto done; + } break; + case 4: /* CC (!C) */ + case 5: /* CS (C) */ + /* Some cases fold C into X. */ + if (op == CC_OP_ADD || op == CC_OP_SUB) { + tcond = TCG_COND_NE; + c->v1 = QREG_CC_X; + goto done; + } + /* fallthru */ + case 8: /* VC (!V) */ + case 9: /* VS (V) */ + /* Logic operations clear V and C. */ + if (op == CC_OP_LOGIC) { + tcond = TCG_COND_NEVER; + c->v2 = c->v1; + } + break; + } + + /* Otherwise, flush flag state to CC_OP_FLAGS. */ + gen_flush_flags(s); + + switch (cond) { + case 0: /* T */ + case 1: /* F */ + default: + /* Invalid, or handled above. */ + abort(); case 2: /* HI (!C && !Z) -> !(C || Z)*/ case 3: /* LS (C || Z) */ c->v1 = tmp = tcg_temp_new(); @@ -830,10 +927,9 @@ static void gen_cc_cond(DisasCompare *c, DisasContext *s, int cond) tcg_temp_free(tmp2); tcond = TCG_COND_LT; break; - default: - /* Should ever happen. */ - abort(); } + + done: if ((cond & 1) == 0) { tcond = tcg_invert_cond(tcond); } -- 2.5.5