From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55815) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQUFu-0006HM-GB for qemu-devel@nongnu.org; Thu, 29 Jun 2017 03:52:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dQUFt-0005x3-LU for qemu-devel@nongnu.org; Thu, 29 Jun 2017 03:52:50 -0400 Received: from mail-yb0-x244.google.com ([2607:f8b0:4002:c09::244]:34577) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dQUFt-0005wv-GF for qemu-devel@nongnu.org; Thu, 29 Jun 2017 03:52:49 -0400 Received: by mail-yb0-x244.google.com with SMTP id b189so3583710yba.1 for ; Thu, 29 Jun 2017 00:52:49 -0700 (PDT) From: Pranith Kumar Date: Thu, 29 Jun 2017 03:52:43 -0400 Message-Id: <20170629075243.26984-4-bobby.prani@gmail.com> In-Reply-To: <20170629075243.26984-1-bobby.prani@gmail.com> References: <20170629075243.26984-1-bobby.prani@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH v3 3/3] tcg/aarch64: Enable indirect jump path using LDR (literal) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: alex.bennee@linaro.org Cc: qemu-devel@nongnu.org, rth@twiddle.net This patch enables the indirect jump path using an LDR (literal) instruction. It will be interesting to test and see which performs better among the two paths. CC: Richard Henderson CC: Alex Bennée Signed-off-by: Pranith Kumar --- tcg/aarch64/tcg-target.inc.c | 42 ++++++++++++++++++++++++++++-------------- 1 file changed, 28 insertions(+), 14 deletions(-) diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c index b7670ecc90..5381c31b45 100644 --- a/tcg/aarch64/tcg-target.inc.c +++ b/tcg/aarch64/tcg-target.inc.c @@ -269,6 +269,8 @@ typedef enum { I3207_BLR = 0xd63f0000, I3207_RET = 0xd65f0000, + /* Load literal for loading the address at pc-relative offset */ + I3305_LDR = 0x58000000, /* Load/store register. Described here as 3.3.12, but the helper that emits them can transform to 3.3.10 or 3.3.13. */ I3312_STRB = 0x38000000 | LDST_ST << 22 | MO_8 << 30, @@ -389,6 +391,11 @@ static inline uint32_t tcg_in32(TCGContext *s) #define tcg_out_insn(S, FMT, OP, ...) \ glue(tcg_out_insn_,FMT)(S, glue(glue(glue(I,FMT),_),OP), ## __VA_ARGS__) +static void tcg_out_insn_3305(TCGContext *s, AArch64Insn insn, int imm19, TCGReg rt) +{ + tcg_out32(s, insn | (imm19 & 0x7ffff) << 5 | rt); +} + static void tcg_out_insn_3201(TCGContext *s, AArch64Insn insn, TCGType ext, TCGReg rt, int imm19) { @@ -864,6 +871,8 @@ static inline void tcg_out_call(TCGContext *s, tcg_insn_unit *target) } } +#ifdef USE_DIRECT_JUMP + void aarch64_tb_set_jmp_target(uintptr_t jmp_addr, uintptr_t addr) { tcg_insn_unit *code_ptr = (tcg_insn_unit *)jmp_addr; @@ -881,6 +890,8 @@ void aarch64_tb_set_jmp_target(uintptr_t jmp_addr, uintptr_t addr) flush_icache_range(jmp_addr, jmp_addr + 8); } +#endif + static inline void tcg_out_goto_label(TCGContext *s, TCGLabel *l) { if (!l->has_value) { @@ -1392,21 +1403,24 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, break; case INDEX_op_goto_tb: -#ifndef USE_DIRECT_JUMP -#error "USE_DIRECT_JUMP required for aarch64" -#endif - /* consistency for USE_DIRECT_JUMP */ - tcg_debug_assert(s->tb_jmp_insn_offset != NULL); - /* Ensure that ADRP+ADD are 8-byte aligned so that an atomic - write can be used to patch the target address. */ - if ((uintptr_t)s->code_ptr & 7) { - tcg_out32(s, NOP); + if (s->tb_jmp_insn_offset != NULL) { + /* USE_DIRECT_JUMP */ + /* Ensure that ADRP+ADD are 8-byte aligned so that an atomic + write can be used to patch the target address. */ + if ((uintptr_t)s->code_ptr & 7) { + tcg_out32(s, NOP); + } + s->tb_jmp_insn_offset[a0] = tcg_current_code_size(s); + /* actual branch destination will be patched by + aarch64_tb_set_jmp_target later, beware of retranslation */ + tcg_out_insn(s, 3406, ADRP, TCG_REG_TMP, 0); + tcg_out_insn(s, 3401, ADDI, TCG_TYPE_I64, TCG_REG_TMP, TCG_REG_TMP, 0); + } else { + /* !USE_DIRECT_JUMP */ + tcg_debug_assert(s->tb_jmp_target_addr != NULL); + intptr_t offset = tcg_pcrel_diff(s, (s->tb_jmp_target_addr + a0)) >> 2; + tcg_out_insn(s, 3305, LDR, offset, TCG_REG_TMP); } - s->tb_jmp_insn_offset[a0] = tcg_current_code_size(s); - /* actual branch destination will be patched by - aarch64_tb_set_jmp_target later, beware of retranslation */ - tcg_out_insn(s, 3406, ADRP, TCG_REG_TMP, 0); - tcg_out_insn(s, 3401, ADDI, TCG_TYPE_I64, TCG_REG_TMP, TCG_REG_TMP, 0); tcg_out_callr(s, TCG_REG_TMP); s->tb_jmp_reset_offset[a0] = tcg_current_code_size(s); break; -- 2.13.0