From patchwork Thu Jan 7 18:29:11 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Richard Henderson X-Patchwork-Id: 43321 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 0F813B7C98 for ; Thu, 21 Jan 2010 04:56:02 +1100 (EST) Received: from localhost ([127.0.0.1]:43502 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NXeik-0006Zj-5A for incoming@patchwork.ozlabs.org; Wed, 20 Jan 2010 12:51:58 -0500 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NXeFT-0008GA-B7 for qemu-devel@nongnu.org; Wed, 20 Jan 2010 12:21:43 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NXeFQ-0008BN-HP for qemu-devel@nongnu.org; Wed, 20 Jan 2010 12:21:40 -0500 Received: from [199.232.76.173] (port=48764 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NXeFN-0008Aq-3N for qemu-devel@nongnu.org; Wed, 20 Jan 2010 12:21:37 -0500 Received: from are.twiddle.net ([75.149.56.221]:44182) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NXeFK-00015b-IH for qemu-devel@nongnu.org; Wed, 20 Jan 2010 12:21:36 -0500 Received: by are.twiddle.net (Postfix, from userid 5000) id 370CCA63; Wed, 20 Jan 2010 09:21:32 -0800 (PST) Message-Id: <4ba6d9d289bb8b90d6e198b58cecb93a80a43534.1264007896.git.rth@twiddle.net> In-Reply-To: References: From: Richard Henderson Date: Thu, 7 Jan 2010 10:29:11 -0800 To: qemu-devel@nongnu.org X-detected-operating-system: by monty-python.gnu.org: GNU/Linux 2.6 (newer, 2) Cc: aurelien@aurel32.net Subject: [Qemu-devel] [PATCH 4/6] tcg-i386: Implement small forward branches. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org There are places, like brcond2, where we know that the destination of a forward branch will be within 127 bytes. Add the R_386_PC8 relocation type to support this. Add a flag to tcg_out_jxx and tcg_out_brcond* to enable it. Set the flag in the brcond2 label_next branches; pass along the input flag otherwise. Signed-off-by: Richard Henderson --- elf.h | 2 + tcg/i386/tcg-target.c | 116 +++++++++++++++++++++++++++++++++---------------- 2 files changed, 80 insertions(+), 38 deletions(-) diff --git a/elf.h b/elf.h index 11674d7..c84c8ab 100644 --- a/elf.h +++ b/elf.h @@ -243,6 +243,8 @@ typedef struct { #define R_386_GOTOFF 9 #define R_386_GOTPC 10 #define R_386_NUM 11 +/* Not a dynamic reloc, so not included in R_386_NUM. Used in TCG. */ +#define R_386_PC8 23 #define R_MIPS_NONE 0 #define R_MIPS_16 1 diff --git a/tcg/i386/tcg-target.c b/tcg/i386/tcg-target.c index 972b102..e1691b3 100644 --- a/tcg/i386/tcg-target.c +++ b/tcg/i386/tcg-target.c @@ -61,6 +61,12 @@ static void patch_reloc(uint8_t *code_ptr, int type, case R_386_PC32: *(uint32_t *)code_ptr = value - (long)code_ptr; break; + case R_386_PC8: + value -= (long)code_ptr; + if (value != (int8_t)value) + tcg_abort(); + *(uint8_t *)code_ptr = value; + break; default: tcg_abort(); } @@ -305,7 +311,8 @@ static void tcg_out_addi(TCGContext *s, int reg, tcg_target_long val) tgen_arithi(s, ARITH_ADD, reg, val, 0); } -static void tcg_out_jxx(TCGContext *s, int opc, int label_index) +/* Use SMALL != 0 to force a short forward branch. */ +static void tcg_out_jxx(TCGContext *s, int opc, int label_index, int small) { int32_t val, val1; TCGLabel *l = &s->labels[label_index]; @@ -314,12 +321,16 @@ static void tcg_out_jxx(TCGContext *s, int opc, int label_index) val = l->u.value - (tcg_target_long)s->code_ptr; val1 = val - 2; if ((int8_t)val1 == val1) { - if (opc == -1) + if (opc == -1) { tcg_out8(s, 0xeb); - else + } else { tcg_out8(s, 0x70 + opc); + } tcg_out8(s, val1); } else { + if (small) { + tcg_abort(); + } if (opc == -1) { tcg_out8(s, 0xe9); tcg_out32(s, val - 5); @@ -329,6 +340,14 @@ static void tcg_out_jxx(TCGContext *s, int opc, int label_index) tcg_out32(s, val - 6); } } + } else if (small) { + if (opc == -1) { + tcg_out8(s, 0xeb); + } else { + tcg_out8(s, 0x70 + opc); + } + tcg_out_reloc(s, s->code_ptr, R_386_PC8, label_index, -1); + s->code_ptr += 1; } else { if (opc == -1) { tcg_out8(s, 0xe9); @@ -343,7 +362,7 @@ static void tcg_out_jxx(TCGContext *s, int opc, int label_index) static void tcg_out_brcond(TCGContext *s, int cond, TCGArg arg1, TCGArg arg2, int const_arg2, - int label_index) + int label_index, int small) { if (const_arg2) { if (arg2 == 0) { @@ -355,64 +374,84 @@ static void tcg_out_brcond(TCGContext *s, int cond, } else { tcg_out_modrm(s, 0x01 | (ARITH_CMP << 3), arg2, arg1); } - tcg_out_jxx(s, tcg_cond_to_jcc[cond], label_index); + tcg_out_jxx(s, tcg_cond_to_jcc[cond], label_index, small); } /* XXX: we implement it at the target level to avoid having to handle cross basic blocks temporaries */ -static void tcg_out_brcond2(TCGContext *s, - const TCGArg *args, const int *const_args) +static void tcg_out_brcond2(TCGContext *s, const TCGArg *args, + const int *const_args, int small) { int label_next; label_next = gen_new_label(); switch(args[4]) { case TCG_COND_EQ: - tcg_out_brcond(s, TCG_COND_NE, args[0], args[2], const_args[2], label_next); - tcg_out_brcond(s, TCG_COND_EQ, args[1], args[3], const_args[3], args[5]); + tcg_out_brcond(s, TCG_COND_NE, args[0], args[2], const_args[2], + label_next, 1); + tcg_out_brcond(s, TCG_COND_EQ, args[1], args[3], const_args[3], + args[5], small); break; case TCG_COND_NE: - tcg_out_brcond(s, TCG_COND_NE, args[0], args[2], const_args[2], args[5]); - tcg_out_brcond(s, TCG_COND_NE, args[1], args[3], const_args[3], args[5]); + tcg_out_brcond(s, TCG_COND_NE, args[0], args[2], const_args[2], + args[5], small); + tcg_out_brcond(s, TCG_COND_NE, args[1], args[3], const_args[3], + args[5], small); break; case TCG_COND_LT: - tcg_out_brcond(s, TCG_COND_LT, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_LTU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_LT, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_LTU, args[0], args[2], const_args[2], + args[5], small); break; case TCG_COND_LE: - tcg_out_brcond(s, TCG_COND_LT, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_LEU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_LT, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_LEU, args[0], args[2], const_args[2], + args[5], small); break; case TCG_COND_GT: - tcg_out_brcond(s, TCG_COND_GT, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_GTU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_GT, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_GTU, args[0], args[2], const_args[2], + args[5], small); break; case TCG_COND_GE: - tcg_out_brcond(s, TCG_COND_GT, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_GEU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_GT, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_GEU, args[0], args[2], const_args[2], + args[5], small); break; case TCG_COND_LTU: - tcg_out_brcond(s, TCG_COND_LTU, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_LTU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_LTU, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_LTU, args[0], args[2], const_args[2], + args[5], small); break; case TCG_COND_LEU: - tcg_out_brcond(s, TCG_COND_LTU, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_LEU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_LTU, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_LEU, args[0], args[2], const_args[2], + args[5], small); break; case TCG_COND_GTU: - tcg_out_brcond(s, TCG_COND_GTU, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_GTU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_GTU, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_GTU, args[0], args[2], const_args[2], + args[5], small); break; case TCG_COND_GEU: - tcg_out_brcond(s, TCG_COND_GTU, args[1], args[3], const_args[3], args[5]); - tcg_out_jxx(s, JCC_JNE, label_next); - tcg_out_brcond(s, TCG_COND_GEU, args[0], args[2], const_args[2], args[5]); + tcg_out_brcond(s, TCG_COND_GTU, args[1], args[3], const_args[3], + args[5], small); + tcg_out_jxx(s, JCC_JNE, label_next, 1); + tcg_out_brcond(s, TCG_COND_GEU, args[0], args[2], const_args[2], + args[5], small); break; default: tcg_abort(); @@ -913,7 +952,7 @@ static inline void tcg_out_op(TCGContext *s, int opc, } break; case INDEX_op_br: - tcg_out_jxx(s, JCC_JMP, args[0]); + tcg_out_jxx(s, JCC_JMP, args[0], 0); break; case INDEX_op_movi_i32: tcg_out_movi(s, TCG_TYPE_I32, args[0], args[1]); @@ -1044,10 +1083,11 @@ static inline void tcg_out_op(TCGContext *s, int opc, tcg_out_modrm(s, 0x01 | (ARITH_SBB << 3), args[5], args[1]); break; case INDEX_op_brcond_i32: - tcg_out_brcond(s, args[2], args[0], args[1], const_args[1], args[3]); + tcg_out_brcond(s, args[2], args[0], args[1], const_args[1], + args[3], 0); break; case INDEX_op_brcond2_i32: - tcg_out_brcond2(s, args, const_args); + tcg_out_brcond2(s, args, const_args, 0); break; case INDEX_op_bswap16_i32: