diff options
| author | Richard Henderson <rth@twiddle.net> | 2014-03-25 17:11:37 -0400 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2014-03-27 16:33:01 -0400 |
| commit | 1a8e80d7e82aa385ad887dba5d039e399a18264b (patch) | |
| tree | a908a6638484be7de25484dc08ab135d9fb677f1 | |
| parent | 9c5793c5036c7608ff2c87846c6d11f904c08b58 (diff) | |
tcg-arm: Avoid ldrd/strd for user-only emulation
The arm ldrd/strd insns must cause alignment traps, whereas
at least for armv7 ldr/str must handle unaligned operations.
While this is hardly the only problem facing user-only emu,
this solves one problem for i386 on armv7 emulation.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Huw Davies <huw@codeweavers.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
| -rw-r--r-- | tcg/arm/tcg-target.c | 21 |
1 files changed, 17 insertions, 4 deletions
diff --git a/tcg/arm/tcg-target.c b/tcg/arm/tcg-target.c index c8884b31f4..a65fc658e1 100644 --- a/tcg/arm/tcg-target.c +++ b/tcg/arm/tcg-target.c @@ -60,6 +60,13 @@ static int arm_arch = __ARM_ARCH; bool use_idiv_instructions; #endif +/* ??? Ought to think about changing CONFIG_SOFTMMU to always defined. */ +#ifdef CONFIG_SOFTMMU +# define USING_SOFTMMU 1 +#else +# define USING_SOFTMMU 0 +#endif + #ifndef NDEBUG static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = { "%r0", @@ -1404,7 +1411,9 @@ static inline void tcg_out_qemu_ld_index(TCGContext *s, TCGMemOp opc, TCGReg dl = (bswap ? datahi : datalo); TCGReg dh = (bswap ? datalo : datahi); - if (use_armv6_instructions && (dl & 1) == 0 && dh == dl + 1) { + /* Avoid ldrd for user-only emulation, to handle unaligned. */ + if (USING_SOFTMMU && use_armv6_instructions + && (dl & 1) == 0 && dh == dl + 1) { tcg_out_ldrd_r(s, COND_AL, dl, addrlo, addend); } else if (dl != addend) { tcg_out_ld32_rwb(s, COND_AL, dl, addend, addrlo); @@ -1463,7 +1472,9 @@ static inline void tcg_out_qemu_ld_direct(TCGContext *s, TCGMemOp opc, TCGReg dl = (bswap ? datahi : datalo); TCGReg dh = (bswap ? datalo : datahi); - if (use_armv6_instructions && (dl & 1) == 0 && dh == dl + 1) { + /* Avoid ldrd for user-only emulation, to handle unaligned. */ + if (USING_SOFTMMU && use_armv6_instructions + && (dl & 1) == 0 && dh == dl + 1) { tcg_out_ldrd_8(s, COND_AL, dl, addrlo, 0); } else if (dl == addrlo) { tcg_out_ld32_12(s, COND_AL, dh, addrlo, bswap ? 0 : 4); @@ -1548,12 +1559,13 @@ static inline void tcg_out_qemu_st_index(TCGContext *s, int cond, TCGMemOp opc, } break; case MO_64: + /* Avoid strd for user-only emulation, to handle unaligned. */ if (bswap) { tcg_out_bswap32(s, cond, TCG_REG_R0, datahi); tcg_out_st32_rwb(s, cond, TCG_REG_R0, addend, addrlo); tcg_out_bswap32(s, cond, TCG_REG_R0, datalo); tcg_out_st32_12(s, cond, TCG_REG_R0, addend, 4); - } else if (use_armv6_instructions + } else if (USING_SOFTMMU && use_armv6_instructions && (datalo & 1) == 0 && datahi == datalo + 1) { tcg_out_strd_r(s, cond, datalo, addrlo, addend); } else { @@ -1592,12 +1604,13 @@ static inline void tcg_out_qemu_st_direct(TCGContext *s, TCGMemOp opc, } break; case MO_64: + /* Avoid strd for user-only emulation, to handle unaligned. */ if (bswap) { tcg_out_bswap32(s, COND_AL, TCG_REG_R0, datahi); tcg_out_st32_12(s, COND_AL, TCG_REG_R0, addrlo, 0); tcg_out_bswap32(s, COND_AL, TCG_REG_R0, datalo); tcg_out_st32_12(s, COND_AL, TCG_REG_R0, addrlo, 4); - } else if (use_armv6_instructions + } else if (USING_SOFTMMU && use_armv6_instructions && (datalo & 1) == 0 && datahi == datalo + 1) { tcg_out_strd_8(s, COND_AL, datalo, addrlo, 0); } else { |