diff mbox series

[v4,4/7] tcg/arm: Check alignment for ldrd and strd

Message ID 20220108063313.477784-5-richard.henderson@linaro.org
State Superseded
Headers show
Series tcg/arm: Unaligned access and other cleanup | expand

Commit Message

Richard Henderson Jan. 8, 2022, 6:33 a.m. UTC 
We will shortly allow the use of unaligned memory accesses,
and these require proper alignment.  Use get_alignment_bits
to verify and remove USING_SOFTMMU.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
 tcg/arm/tcg-target.c.inc | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

Comments

Peter Maydell Jan. 11, 2022, 11:32 a.m. UTC | #1 
On Sat, 8 Jan 2022 at 06:33, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> We will shortly allow the use of unaligned memory accesses,
> and these require proper alignment.  Use get_alignment_bits
> to verify and remove USING_SOFTMMU.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>  tcg/arm/tcg-target.c.inc | 22 ++++++++--------------
>  1 file changed, 8 insertions(+), 14 deletions(-)
>
> diff --git a/tcg/arm/tcg-target.c.inc b/tcg/arm/tcg-target.c.inc
> index ea8b90e6e2..8a20224dd1 100644
> --- a/tcg/arm/tcg-target.c.inc
> +++ b/tcg/arm/tcg-target.c.inc
> @@ -35,12 +35,6 @@ bool use_neon_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

Removing this ifdef leaves the CONFIG_SOFTMMU ??? comment without
anything it refers to. The perennial question of whether we should
have a linux-user with softmmu isn't very arm-specific, so I
would just delete the ??? comment too.

Anyway
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>

thanks
-- PMM
diff mbox series

Patch

diff --git a/tcg/arm/tcg-target.c.inc b/tcg/arm/tcg-target.c.inc
index ea8b90e6e2..8a20224dd1 100644
--- a/tcg/arm/tcg-target.c.inc
+++ b/tcg/arm/tcg-target.c.inc
@@ -35,12 +35,6 @@  bool use_neon_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
-
 #ifdef CONFIG_DEBUG_TCG
 static const char * const tcg_target_reg_names[TCG_TARGET_NB_REGS] = {
     "%r0",  "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
@@ -1621,8 +1615,8 @@  static void tcg_out_qemu_ld_index(TCGContext *s, MemOp opc,
         tcg_out_ld32_r(s, COND_AL, datalo, addrlo, addend);
         break;
     case MO_Q:
-        /* Avoid ldrd for user-only emulation, to handle unaligned.  */
-        if (USING_SOFTMMU
+        /* LDRD requires alignment; double-check that. */
+        if (get_alignment_bits(opc) >= MO_64
             && (datalo & 1) == 0 && datahi == datalo + 1) {
             tcg_out_ldrd_r(s, COND_AL, datalo, addrlo, addend);
         } else if (datalo != addend) {
@@ -1664,8 +1658,8 @@  static void tcg_out_qemu_ld_direct(TCGContext *s, MemOp opc, TCGReg datalo,
         tcg_out_ld32_12(s, COND_AL, datalo, addrlo, 0);
         break;
     case MO_Q:
-        /* Avoid ldrd for user-only emulation, to handle unaligned.  */
-        if (USING_SOFTMMU
+        /* LDRD requires alignment; double-check that. */
+        if (get_alignment_bits(opc) >= MO_64
             && (datalo & 1) == 0 && datahi == datalo + 1) {
             tcg_out_ldrd_8(s, COND_AL, datalo, addrlo, 0);
         } else if (datalo == addrlo) {
@@ -1741,8 +1735,8 @@  static void tcg_out_qemu_st_index(TCGContext *s, ARMCond cond, MemOp opc,
         tcg_out_st32_r(s, cond, datalo, addrlo, addend);
         break;
     case MO_64:
-        /* Avoid strd for user-only emulation, to handle unaligned.  */
-        if (USING_SOFTMMU
+        /* STRD requires alignment; double-check that. */
+        if (get_alignment_bits(opc) >= MO_64
             && (datalo & 1) == 0 && datahi == datalo + 1) {
             tcg_out_strd_r(s, cond, datalo, addrlo, addend);
         } else {
@@ -1773,8 +1767,8 @@  static void tcg_out_qemu_st_direct(TCGContext *s, MemOp opc, TCGReg datalo,
         tcg_out_st32_12(s, COND_AL, datalo, addrlo, 0);
         break;
     case MO_64:
-        /* Avoid strd for user-only emulation, to handle unaligned.  */
-        if (USING_SOFTMMU
+        /* STRD requires alignment; double-check that. */
+        if (get_alignment_bits(opc) >= MO_64
             && (datalo & 1) == 0 && datahi == datalo + 1) {
             tcg_out_strd_8(s, COND_AL, datalo, addrlo, 0);
         } else {