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[173.198.77.219]) by smtp.gmail.com with ESMTPSA id w7-v6sm8583248pgr.82.2018.06.14.23.25.50 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 14 Jun 2018 23:25:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=zMN/HXhk8ZSZwT20h0XtqERAHzzy6n6yeZmYNCVvvnM=; b=g9PLFNyCjQTC4TQkCGS+Yg7/FldjWbfFNWg0PJvsWKr2vGSioV/3OvIcy7NFztPZ2C TzdeXYvnq5ljYHbt02OLIabfyBN1qMfKIdxaCVpzo6NfDMFFwGbqRLlzFhiI1LlBxRmo x9jyUQisZbC4fCvKA10ZmEESpiuUPmVOXks5o= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=zMN/HXhk8ZSZwT20h0XtqERAHzzy6n6yeZmYNCVvvnM=; b=G7wB+xQDqIR+MsHa8hOLfjtygXPT6VegN3s9brLZyC6OGNOiTcbMF7YJ2QjI5shYTk fDRCr/0jp6UK8E0ydSYlcH2wxl1mTjTlVWg/3LXIulzhf+SDQObXszriMq0XykVVn/ND xm2PruLrs/xcTf0tbBF1Ip9bds16OsM3Bt1yR327W8cAaxpPkLvnZS+d7LqtRX9P3cIH 7UIQM2zCSPC73AKynvv3hro8BWR/aldsPaM06sr4aumZC1tiJz1sJcf3a2wWveYxaA1r JLdp6LS+us5RtLIG9FNv4HB0PMuK25vxGY4iZ1fE4f7MrahY2+ZtLUsho1TXh69Rz+hr sJDw== X-Gm-Message-State: APt69E3JN97siJupoGE7TVGksY29mW+w/J4uU57cQSGl/yhWvYJeZKbX AANe7Q+C9OQ1So6bKtjwCG6ukzHNgrM= X-Google-Smtp-Source: ADUXVKKYDKzga8FCTMqVMPY7JGEAyJZGh8hWttAL6hXzohtDxPlL/S/DqmnUOEwGWAjMaHWL5YMlvQ== X-Received: by 2002:a17:902:1101:: with SMTP id d1-v6mr455156pla.147.1529043953280; Thu, 14 Jun 2018 23:25:53 -0700 (PDT) From: Richard Henderson To: qemu-devel@nongnu.org Date: Thu, 14 Jun 2018 20:25:47 -1000 Message-Id: <20180615062547.4798-1-richard.henderson@linaro.org> X-Mailer: git-send-email 2.17.1 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2607:f8b0:400e:c01::243 Subject: [Qemu-devel] [PATCH] tcg: Reduce max TB opcode count X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason@zx2c4.com, sstabellini@kernel.org, pmatouse@redhat.com, mst@redhat.com, sw@weilnetz.de, crosthwaite.peter@gmail.com, mdroth@linux.vnet.ibm.com, pbonzini@redhat.com, pjp@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Also, assert that we don't overflow any of two different offsets into the TB. Both unwind and goto_tb both record a uint16_t for later use. Signed-off-by: Richard Henderson Reported-by: "Jason A. Donenfeld" Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- This fixes an arm-softmmu test case forwarded to me by Michael Tsirkin. There is a TB generated from that test case that runs to 7800 opcodes, and compiles to 96k on an x64 host. This overflows the 16-bit offset in which we record the goto_tb reset offset. Because of that overflow, we install a jump destination that goes to neverland. Boom. With this reduced op count, the same TB compiles to about 48k for both x64 and ppc64le hosts, and neither assertion fires. r~ --- tcg/tcg.h | 2 +- tcg/aarch64/tcg-target.inc.c | 2 +- tcg/arm/tcg-target.inc.c | 2 +- tcg/i386/tcg-target.inc.c | 2 +- tcg/mips/tcg-target.inc.c | 2 +- tcg/ppc/tcg-target.inc.c | 4 ++-- tcg/s390/tcg-target.inc.c | 2 +- tcg/sparc/tcg-target.inc.c | 4 ++-- tcg/tcg.c | 13 ++++++++++++- tcg/tci/tcg-target.inc.c | 2 +- 10 files changed, 23 insertions(+), 12 deletions(-) diff --git a/tcg/tcg.h b/tcg/tcg.h index 532d2a0710..2902a51505 100644 --- a/tcg/tcg.h +++ b/tcg/tcg.h @@ -852,7 +852,7 @@ static inline bool tcg_op_buf_full(void) * such that a RISC host can reasonably use a 16-bit signed * branch within the TB. */ - return tcg_ctx->nb_ops >=3D 8000; + return tcg_ctx->nb_ops >=3D 4000; } =20 /* pool based memory allocation */ diff --git a/tcg/aarch64/tcg-target.inc.c b/tcg/aarch64/tcg-target.inc.c index be3192078d..4562d36d1b 100644 --- a/tcg/aarch64/tcg-target.inc.c +++ b/tcg/aarch64/tcg-target.inc.c @@ -1733,7 +1733,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, tcg_out_insn(s, 3305, LDR, offset, TCG_REG_TMP); } tcg_out_insn(s, 3207, BR, TCG_REG_TMP); - s->tb_jmp_reset_offset[a0] =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); break; =20 case INDEX_op_goto_ptr: diff --git a/tcg/arm/tcg-target.inc.c b/tcg/arm/tcg-target.inc.c index 56a32a470f..e1fbf465cb 100644 --- a/tcg/arm/tcg-target.inc.c +++ b/tcg/arm/tcg-target.inc.c @@ -1822,7 +1822,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcod= e opc, tcg_out_movi32(s, COND_AL, base, ptr - dil); } tcg_out_ld32_12(s, COND_AL, TCG_REG_PC, base, dil); - s->tb_jmp_reset_offset[args[0]] =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, args[0]); } break; case INDEX_op_goto_ptr: diff --git a/tcg/i386/tcg-target.inc.c b/tcg/i386/tcg-target.inc.c index 0d0ff524b7..e87b0d445e 100644 --- a/tcg/i386/tcg-target.inc.c +++ b/tcg/i386/tcg-target.inc.c @@ -2245,7 +2245,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcod= e opc, tcg_out_modrm_offset(s, OPC_GRP5, EXT5_JMPN_Ev, -1, (intptr_t)(s->tb_jmp_target_addr + a0)); } - s->tb_jmp_reset_offset[a0] =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); break; case INDEX_op_goto_ptr: /* jmp to the given host address (could be epilogue) */ diff --git a/tcg/mips/tcg-target.inc.c b/tcg/mips/tcg-target.inc.c index ca5f1d4894..cff525373b 100644 --- a/tcg/mips/tcg-target.inc.c +++ b/tcg/mips/tcg-target.inc.c @@ -1744,7 +1744,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcod= e opc, tcg_out_opc_reg(s, OPC_JR, 0, TCG_TMP0, 0); } tcg_out_nop(s); - s->tb_jmp_reset_offset[a0] =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); break; case INDEX_op_goto_ptr: /* jmp to the given host address (could be epilogue) */ diff --git a/tcg/ppc/tcg-target.inc.c b/tcg/ppc/tcg-target.inc.c index 86f7de5f7e..c2f729ee8f 100644 --- a/tcg/ppc/tcg-target.inc.c +++ b/tcg/ppc/tcg-target.inc.c @@ -2025,10 +2025,10 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc= , const TCGArg *args, } tcg_out32(s, MTSPR | RS(TCG_REG_TB) | CTR); tcg_out32(s, BCCTR | BO_ALWAYS); - s->tb_jmp_reset_offset[args[0]] =3D c =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, args[0]); if (USE_REG_TB) { /* For the unlinked case, need to reset TCG_REG_TB. */ - c =3D -c; + c =3D -tcg_current_code_size(s); assert(c =3D=3D (int16_t)c); tcg_out32(s, ADDI | TAI(TCG_REG_TB, TCG_REG_TB, c)); } diff --git a/tcg/s390/tcg-target.inc.c b/tcg/s390/tcg-target.inc.c index 9af6dcef05..17c435ade5 100644 --- a/tcg/s390/tcg-target.inc.c +++ b/tcg/s390/tcg-target.inc.c @@ -1783,7 +1783,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcod= e opc, /* and go there */ tcg_out_insn(s, RR, BCR, S390_CC_ALWAYS, TCG_REG_TB); } - s->tb_jmp_reset_offset[a0] =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); =20 /* For the unlinked path of goto_tb, we need to reset TCG_REG_TB to the beginning of this TB. */ diff --git a/tcg/sparc/tcg-target.inc.c b/tcg/sparc/tcg-target.inc.c index bc673bd8c6..04bdc3df5e 100644 --- a/tcg/sparc/tcg-target.inc.c +++ b/tcg/sparc/tcg-target.inc.c @@ -1388,12 +1388,12 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, tcg_out_arithi(s, TCG_REG_G0, TCG_REG_TB, 0, JMPL); tcg_out_nop(s); } - s->tb_jmp_reset_offset[a0] =3D c =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, a0); =20 /* For the unlinked path of goto_tb, we need to reset TCG_REG_TB to the beginning of this TB. */ if (USE_REG_TB) { - c =3D -c; + c =3D -tcg_current_code_size(s); if (check_fit_i32(c, 13)) { tcg_out_arithi(s, TCG_REG_TB, TCG_REG_TB, c, ARITH_ADD); } else { diff --git a/tcg/tcg.c b/tcg/tcg.c index 1d1dfd7f7c..f27b22bd3c 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -306,6 +306,14 @@ TCGLabel *gen_new_label(void) return l; } =20 +static void set_jmp_reset_offset(TCGContext *s, int which) +{ + size_t off =3D tcg_current_code_size(s); + s->tb_jmp_reset_offset[which] =3D off; + /* Make sure that we didn't overflow the stored offset. */ + assert(s->tb_jmp_reset_offset[which] =3D=3D off); +} + #include "tcg-target.inc.c" =20 /* compare a pointer @ptr and a tb_tc @s */ @@ -3532,7 +3540,10 @@ int tcg_gen_code(TCGContext *s, TranslationBlock *tb) break; case INDEX_op_insn_start: if (num_insns >=3D 0) { - s->gen_insn_end_off[num_insns] =3D tcg_current_code_size(s= ); + size_t off =3D tcg_current_code_size(s); + s->gen_insn_end_off[num_insns] =3D off; + /* Assert that we do not overflow our stored offset. */ + assert(s->gen_insn_end_off[num_insns] =3D=3D off); } num_insns++; for (i =3D 0; i < TARGET_INSN_START_WORDS; ++i) { diff --git a/tcg/tci/tcg-target.inc.c b/tcg/tci/tcg-target.inc.c index cc949bea85..62ed097254 100644 --- a/tcg/tci/tcg-target.inc.c +++ b/tcg/tci/tcg-target.inc.c @@ -574,7 +574,7 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, co= nst TCGArg *args, /* Indirect jump method. */ TODO(); } - s->tb_jmp_reset_offset[args[0]] =3D tcg_current_code_size(s); + set_jmp_reset_offset(s, args[0]); break; case INDEX_op_br: tci_out_label(s, arg_label(args[0])); --=20 2.17.1