From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59358) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gVDVW-00007O-5e for qemu-devel@nongnu.org; Fri, 07 Dec 2018 05:37:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gVDVT-00083g-4l for qemu-devel@nongnu.org; Fri, 07 Dec 2018 05:37:18 -0500 Received: from mail-ot1-x342.google.com ([2607:f8b0:4864:20::342]:41505) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1gVDVS-00082y-Vf for qemu-devel@nongnu.org; Fri, 07 Dec 2018 05:37:15 -0500 Received: by mail-ot1-x342.google.com with SMTP id u16so3339889otk.8 for ; Fri, 07 Dec 2018 02:37:14 -0800 (PST) From: Richard Henderson Date: Fri, 7 Dec 2018 04:36:31 -0600 Message-Id: <20181207103631.28193-27-richard.henderson@linaro.org> In-Reply-To: <20181207103631.28193-1-richard.henderson@linaro.org> References: <20181207103631.28193-1-richard.henderson@linaro.org> Subject: [Qemu-devel] [PATCH 26/26] target/arm: Tidy TBI handling in gen_a64_set_pc List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: peter.maydell@linaro.org, ramana.radhakrishnan@arm.com We can perform this with fewer operations. Signed-off-by: Richard Henderson --- target/arm/translate-a64.c | 65 ++++++++++++++------------------------ 1 file changed, 23 insertions(+), 42 deletions(-) diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 99e1405dff..15080cbb3c 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -261,7 +261,7 @@ void gen_a64_set_pc_im(uint64_t val) /* Load the PC from a generic TCG variable. * * If address tagging is enabled via the TCR TBI bits, then loading - * an address into the PC will clear out any tag in the it: + * an address into the PC will clear out any tag in it: * + for EL2 and EL3 there is only one TBI bit, and if it is set * then the address is zero-extended, clearing bits [63:56] * + for EL0 and EL1, TBI0 controls addresses with bit 55 == 0 @@ -276,56 +276,37 @@ void gen_a64_set_pc_im(uint64_t val) */ static void gen_a64_set_pc(DisasContext *s, TCGv_i64 src) { + bool tbi0 = s->tbi0, tbi1 = s->tbi1; if (s->current_el <= 1) { - /* Test if NEITHER or BOTH TBI values are set. If so, no need to - * examine bit 55 of address, can just generate code. - * If mixed, then test via generated code - */ - if (s->tbi0 && s->tbi1) { - TCGv_i64 tmp_reg = tcg_temp_new_i64(); - /* Both bits set, sign extension from bit 55 into [63:56] will - * cover both cases - */ - tcg_gen_shli_i64(tmp_reg, src, 8); - tcg_gen_sari_i64(cpu_pc, tmp_reg, 8); - tcg_temp_free_i64(tmp_reg); - } else if (!s->tbi0 && !s->tbi1) { - /* Neither bit set, just load it as-is */ - tcg_gen_mov_i64(cpu_pc, src); - } else { - TCGv_i64 tcg_tmpval = tcg_temp_new_i64(); - TCGv_i64 tcg_bit55 = tcg_temp_new_i64(); - TCGv_i64 tcg_zero = tcg_const_i64(0); + if (tbi0 || tbi1) { + /* Sign-extend from bit 55. */ + tcg_gen_sextract_i64(cpu_pc, src, 0, 56); - tcg_gen_andi_i64(tcg_bit55, src, (1ull << 55)); + if (tbi0 != tbi1) { + TCGv_i64 tcg_zero = tcg_const_i64(0); - if (s->tbi0) { - /* tbi0==1, tbi1==0, so 0-fill upper byte if bit 55 = 0 */ - tcg_gen_andi_i64(tcg_tmpval, src, - 0x00FFFFFFFFFFFFFFull); - tcg_gen_movcond_i64(TCG_COND_EQ, cpu_pc, tcg_bit55, tcg_zero, - tcg_tmpval, src); - } else { - /* tbi0==0, tbi1==1, so 1-fill upper byte if bit 55 = 1 */ - tcg_gen_ori_i64(tcg_tmpval, src, - 0xFF00000000000000ull); - tcg_gen_movcond_i64(TCG_COND_NE, cpu_pc, tcg_bit55, tcg_zero, - tcg_tmpval, src); + /* + * The two TBI bits differ. + * If tbi0, then !tbi1: only use the extension if positive. + * if !tbi0, then tbi1: only use the extension if negative. + */ + tcg_gen_movcond_i64(tbi0 ? TCG_COND_GE : TCG_COND_LT, + cpu_pc, cpu_pc, tcg_zero, cpu_pc, src); + tcg_temp_free_i64(tcg_zero); } - tcg_temp_free_i64(tcg_zero); - tcg_temp_free_i64(tcg_bit55); - tcg_temp_free_i64(tcg_tmpval); + return; } - } else { /* EL > 1 */ - if (s->tbi0) { + } else { + if (tbi0) { /* Force tag byte to all zero */ - tcg_gen_andi_i64(cpu_pc, src, 0x00FFFFFFFFFFFFFFull); - } else { - /* Load unmodified address */ - tcg_gen_mov_i64(cpu_pc, src); + tcg_gen_extract_i64(cpu_pc, src, 0, 56); + return; } } + + /* Load unmodified address */ + tcg_gen_mov_i64(cpu_pc, src); } typedef struct DisasCompare64 { -- 2.17.2