From patchwork Wed Mar 28 00:32:19 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [10/14] tcg-sparc: Clean up cruft stemming from attempts to use global registers. Date: Tue, 27 Mar 2012 14:32:19 -0000 From: Richard Henderson X-Patchwork-Id: 149066 Message-Id: <1332894743-27418-11-git-send-email-rth@twiddle.net> To: qemu-devel@nongnu.org Cc: blauwirbel@gmail.com Don't use -ffixed-gN. Don't link statically. Don't save/restore AREG0 around calls. Don't allocate space on the stack for AREG0 save. Signed-off-by: Richard Henderson --- configure | 12 ---------- tcg/sparc/tcg-target.c | 57 ++++++++++++++++-------------------------------- tcg/sparc/tcg-target.h | 18 ++++++--------- 3 files changed, 26 insertions(+), 61 deletions(-) diff --git a/configure b/configure index a79a090..4ae70c0 100755 --- a/configure +++ b/configure @@ -815,19 +815,11 @@ case "$cpu" in sparc) LDFLAGS="-m32 $LDFLAGS" QEMU_CFLAGS="-m32 -mcpu=ultrasparc $QEMU_CFLAGS" - QEMU_CFLAGS="-ffixed-g2 -ffixed-g3 $QEMU_CFLAGS" - if test "$solaris" = "no" ; then - QEMU_CFLAGS="-ffixed-g1 -ffixed-g6 $QEMU_CFLAGS" - fi host_guest_base="yes" ;; sparc64) LDFLAGS="-m64 $LDFLAGS" QEMU_CFLAGS="-m64 -mcpu=ultrasparc $QEMU_CFLAGS" - QEMU_CFLAGS="-ffixed-g5 -ffixed-g6 -ffixed-g7 $QEMU_CFLAGS" - if test "$solaris" != "no" ; then - QEMU_CFLAGS="-ffixed-g1 $QEMU_CFLAGS" - fi host_guest_base="yes" ;; s390) @@ -3817,10 +3809,6 @@ fi if test "$target_linux_user" = "yes" -o "$target_bsd_user" = "yes" ; then case "$ARCH" in - sparc) - # -static is used to avoid g1/g3 usage by the dynamic linker - ldflags="$linker_script -static $ldflags" - ;; alpha | s390x) # The default placement of the application is fine. ;; diff --git a/tcg/sparc/tcg-target.c b/tcg/sparc/tcg-target.c index ad040fb..88c5140 100644 --- a/tcg/sparc/tcg-target.c +++ b/tcg/sparc/tcg-target.c @@ -167,9 +167,6 @@ static int target_parse_constraint(TCGArgConstraint *ct, const char **pct_str) tcg_regset_reset_reg(ct->u.regs, TCG_REG_O0); tcg_regset_reset_reg(ct->u.regs, TCG_REG_O1); tcg_regset_reset_reg(ct->u.regs, TCG_REG_O2); -#ifdef CONFIG_TCG_PASS_AREG0 - tcg_regset_reset_reg(ct->u.regs, TCG_REG_O3); -#endif break; case 'I': ct->ct |= TCG_CT_CONST_S11; @@ -690,11 +687,22 @@ static void tcg_out_setcond2_i32(TCGContext *s, TCGCond cond, TCGArg ret, /* Generate global QEMU prologue and epilogue code */ static void tcg_target_qemu_prologue(TCGContext *s) { - tcg_set_frame(s, TCG_REG_I6, TCG_TARGET_CALL_STACK_OFFSET, - CPU_TEMP_BUF_NLONGS * (int)sizeof(long)); + int tmp_buf_size, frame_size; + + /* The TCG temp buffer is at the top of the frame, immediately + below the frame pointer. */ + tmp_buf_size = CPU_TEMP_BUF_NLONGS * (int)sizeof(long); + tcg_set_frame(s, TCG_REG_I6, TCG_TARGET_STACK_BIAS - tmp_buf_size, + tmp_buf_size); + + /* TCG_TARGET_CALL_STACK_OFFSET includes the stack bias, but is + otherwise the minimal frame usable by callees. */ + frame_size = TCG_TARGET_CALL_STACK_OFFSET - TCG_TARGET_STACK_BIAS; + frame_size += TCG_STATIC_CALL_ARGS_SIZE + tmp_buf_size; + frame_size += TCG_TARGET_STACK_ALIGN - 1; + frame_size &= -TCG_TARGET_STACK_ALIGN; tcg_out32(s, SAVE | INSN_RD(TCG_REG_O6) | INSN_RS1(TCG_REG_O6) | - INSN_IMM13(-(TCG_TARGET_STACK_MINFRAME + - CPU_TEMP_BUF_NLONGS * (int)sizeof(long)))); + INSN_IMM13(-frame_size)); #ifdef CONFIG_USE_GUEST_BASE if (GUEST_BASE != 0) { @@ -707,6 +715,8 @@ static void tcg_target_qemu_prologue(TCGContext *s) INSN_RS2(TCG_REG_G0)); /* delay slot */ tcg_out_nop(s); + + /* No epilogue required. We issue ret + restore directly in the TB. */ } #if defined(CONFIG_SOFTMMU) @@ -911,12 +921,6 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int sizeop) tcg_out_mov(s, TCG_TYPE_REG, tcg_target_call_iarg_regs[n++], args[addrlo_idx]); - /* Store AREG0 in stack to avoid ugly glibc bugs that mangle - global registers */ - tcg_out_st(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK, - TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE - - sizeof(long)); - /* qemu_ld_helper[s_bits](arg0, arg1) */ tcg_out32(s, CALL | ((((tcg_target_ulong)qemu_ld_helpers[s_bits] - (tcg_target_ulong)s->code_ptr) >> 2) @@ -924,11 +928,6 @@ static void tcg_out_qemu_ld(TCGContext *s, const TCGArg *args, int sizeop) /* delay slot */ tcg_out_movi(s, TCG_TYPE_I32, tcg_target_call_iarg_regs[n], memi); - /* Reload AREG0. */ - tcg_out_ld(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK, - TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE - - sizeof(long)); - n = tcg_target_call_oarg_regs[0]; /* datalo = sign_extend(arg0) */ switch (sizeop) { @@ -1043,12 +1042,6 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int sizeop) } tcg_out_mov(s, TCG_TYPE_REG, tcg_target_call_iarg_regs[n++], datalo); - /* Store AREG0 in stack to avoid ugly glibc bugs that mangle - global registers */ - tcg_out_st(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK, - TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE - - sizeof(long)); - /* qemu_st_helper[s_bits](arg0, arg1, arg2) */ tcg_out32(s, CALL | ((((tcg_target_ulong)qemu_st_helpers[sizeop] - (tcg_target_ulong)s->code_ptr) >> 2) @@ -1056,11 +1049,6 @@ static void tcg_out_qemu_st(TCGContext *s, const TCGArg *args, int sizeop) /* delay slot */ tcg_out_movi(s, TCG_TYPE_REG, tcg_target_call_iarg_regs[n], memi); - /* Reload AREG0. */ - tcg_out_ld(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK, - TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE - - sizeof(long)); - *label_ptr |= INSN_OFF19((unsigned long)s->code_ptr - (unsigned long)label_ptr); #else @@ -1123,15 +1111,8 @@ static inline void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, tcg_out32(s, JMPL | INSN_RD(TCG_REG_O7) | INSN_RS1(TCG_REG_I5) | INSN_RS2(TCG_REG_G0)); } - /* Store AREG0 in stack to avoid ugly glibc bugs that mangle - global registers */ - // delay slot - tcg_out_st(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK, - TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE - - sizeof(long)); - tcg_out_ld(s, TCG_TYPE_REG, TCG_AREG0, TCG_REG_CALL_STACK, - TCG_TARGET_CALL_STACK_OFFSET - TCG_STATIC_CALL_ARGS_SIZE - - sizeof(long)); + /* delay slot */ + tcg_out_nop(s); break; case INDEX_op_jmp: case INDEX_op_br: diff --git a/tcg/sparc/tcg-target.h b/tcg/sparc/tcg-target.h index 31b98e2..b7afa7b 100644 --- a/tcg/sparc/tcg-target.h +++ b/tcg/sparc/tcg-target.h @@ -66,20 +66,16 @@ typedef enum { #define TCG_CT_CONST_S13 0x200 /* used for function call generation */ -#define TCG_REG_CALL_STACK TCG_REG_I6 +#define TCG_REG_CALL_STACK TCG_REG_O6 #if TCG_TARGET_REG_BITS == 64 -// Reserve space for AREG0 -#define TCG_TARGET_STACK_MINFRAME (176 + 4 * (int)sizeof(long) + \ - TCG_STATIC_CALL_ARGS_SIZE) -#define TCG_TARGET_CALL_STACK_OFFSET (2047 - 16) -#define TCG_TARGET_STACK_ALIGN 16 +#define TCG_TARGET_STACK_BIAS 2047 +#define TCG_TARGET_STACK_ALIGN 16 +#define TCG_TARGET_CALL_STACK_OFFSET (128 + 6*8 + TCG_TARGET_STACK_BIAS) #else -// AREG0 + one word for alignment -#define TCG_TARGET_STACK_MINFRAME (92 + (2 + 1) * (int)sizeof(long) + \ - TCG_STATIC_CALL_ARGS_SIZE) -#define TCG_TARGET_CALL_STACK_OFFSET TCG_TARGET_STACK_MINFRAME -#define TCG_TARGET_STACK_ALIGN 8 +#define TCG_TARGET_STACK_BIAS 0 +#define TCG_TARGET_STACK_ALIGN 8 +#define TCG_TARGET_CALL_STACK_OFFSET (64 + 4 + 6*4) #endif #if TCG_TARGET_REG_BITS == 64