From patchwork Wed Mar 16 15:21:31 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Maydell X-Patchwork-Id: 638 Return-Path: Delivered-To: unknown Received: from imap.gmail.com (74.125.159.109) by localhost6.localdomain6 with IMAP4-SSL; 08 Jun 2011 14:44:17 -0000 Delivered-To: patches@linaro.org Received: by 10.151.46.5 with SMTP id y5cs11181ybj; Wed, 16 Mar 2011 08:21:36 -0700 (PDT) Received: by 10.227.140.159 with SMTP id i31mr90259wbu.166.1300288895627; Wed, 16 Mar 2011 08:21:35 -0700 (PDT) Received: from mnementh.archaic.org.uk (mnementh.archaic.org.uk [81.2.115.146]) by mx.google.com with ESMTPS id j5si93698wbc.45.2011.03.16.08.21.33 (version=TLSv1/SSLv3 cipher=OTHER); Wed, 16 Mar 2011 08:21:34 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of pm215@archaic.org.uk designates 81.2.115.146 as permitted sender) client-ip=81.2.115.146; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of pm215@archaic.org.uk designates 81.2.115.146 as permitted sender) smtp.mail=pm215@archaic.org.uk Received: from pm215 by mnementh.archaic.org.uk with local (Exim 4.72) (envelope-from ) id 1PzsXT-0007xB-Gi; Wed, 16 Mar 2011 15:21:31 +0000 From: Peter Maydell To: qemu-devel@nongnu.org Cc: patches@linaro.org, Andrzej Zaborowski Subject: [PATCH] tcg/arm: Support host code being compiled for Thumb Date: Wed, 16 Mar 2011 15:21:31 +0000 Message-Id: <1300288891-30550-1-git-send-email-peter.maydell@linaro.org> X-Mailer: git-send-email 1.7.2.3 Although the TCG generated code is always in ARM mode, it is possible that the host code was compiled by gcc in Thumb mode (this is often the default for Linux distributions targeting ARM v7 only). Handle this by using BLX imm when doing a call from ARM into Thumb mode. Since BLX imm is not a conditionalisable instruction, we make tcg_out_call() no longer take a condition code; we were only ever using it with COND_AL anyway. Signed-off-by: Peter Maydell --- tcg/arm/tcg-target.c | 35 ++++++++++++++++++++++++++--------- 1 files changed, 26 insertions(+), 9 deletions(-) diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c index 918e2f7..d7ee554 100644 --- a/tcg/arm/tcg-target.c +++ b/tcg/arm/tcg-target.c @@ -375,6 +375,12 @@ static inline void tcg_out_blx(TCGContext *s, int cond, int rn) tcg_out32(s, (cond << 28) | 0x012fff30 | rn); } +static inline void tcg_out_blx_imm(TCGContext *s, int32_t offset) +{ + tcg_out32(s, 0xfa000000 | ((offset & 2) << 23) | + (((offset - 8) >> 2) & 0x00ffffff)); +} + static inline void tcg_out_dat_reg(TCGContext *s, int cond, int opc, int rd, int rn, int rm, int shift) { @@ -840,6 +846,11 @@ static inline void tcg_out_goto(TCGContext *s, int cond, uint32_t addr) { int32_t val; + if (addr & 1) { + /* goto to a Thumb destination isn't supported */ + tcg_abort(); + } + val = addr - (tcg_target_long) s->code_ptr; if (val - 8 < 0x01fffffd && val - 8 > -0x01fffffd) tcg_out_b(s, cond, val); @@ -860,14 +871,22 @@ static inline void tcg_out_goto(TCGContext *s, int cond, uint32_t addr) } } -static inline void tcg_out_call(TCGContext *s, int cond, uint32_t addr) +static inline void tcg_out_call(TCGContext *s, uint32_t addr) { int32_t val; val = addr - (tcg_target_long) s->code_ptr; - if (val < 0x01fffffd && val > -0x01fffffd) - tcg_out_bl(s, cond, val); - else { + if (((val - 8) < 0x02000000) && ((val - 8) >= -0x02000000)) { + if (addr & 1) { + /* Use BLX if the target is in Thumb mode */ + if (!use_armv5_instructions) { + tcg_abort(); + } + tcg_out_blx_imm(s, val); + } else { + tcg_out_bl(s, COND_AL, val); + } + } else { #if 1 tcg_abort(); #else @@ -1063,8 +1082,7 @@ static inline void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int opc) TCG_REG_R1, 0, addr_reg2, SHIFT_IMM_LSL(0)); tcg_out_dat_imm(s, COND_AL, ARITH_MOV, TCG_REG_R2, 0, mem_index); # endif - tcg_out_bl(s, COND_AL, (tcg_target_long) qemu_ld_helpers[s_bits] - - (tcg_target_long) s->code_ptr); + tcg_out_call(s, (tcg_target_long)qemu_ld_helpers[s_bits]); switch (opc) { case 0 | 4: @@ -1330,8 +1348,7 @@ static inline void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int opc) } # endif - tcg_out_bl(s, COND_AL, (tcg_target_long) qemu_st_helpers[s_bits] - - (tcg_target_long) s->code_ptr); + tcg_out_call(s, (tcg_target_long)qemu_st_helpers[s_bits]); if (opc == 3) tcg_out_dat_imm(s, COND_AL, ARITH_ADD, TCG_REG_R13, TCG_REG_R13, 0x10); @@ -1443,7 +1460,7 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, break; case INDEX_op_call: if (const_args[0]) - tcg_out_call(s, COND_AL, args[0]); + tcg_out_call(s, args[0]); else tcg_out_callr(s, COND_AL, args[0]); break;