[Qemu-devel] [PATCH v4 0/3] target-mips: Add support for misaligned accesses

[Qemu-devel] [PATCH v4 0/3] target-mips: Add support for misaligned accesses

[Yongbok Kim]

This patch set adds support for misaligned memory accesses in MIPS architecture
Release 6 and MIPS SIMD Architecture.

The behaviour, semantics, and architecture specifications of misaligned memory
accesses are described in:
MIPS Architecture For Programmers Volume I-A: Introduction to the MIPS64
Architecture, Appendix B Misaligned Memory Accesses.
Available at http://www.imgtec.com/mips/architectures/mips64.asp

Regards,
Yongbok

v4: 
* Removed the work-around per the recent TCG change for misaligned accesses
* Added probe_write() (Richard)
* Used helper_ret_*_mmu directly (Richard)
* Removed TLB checking for MSA LD (Richard)
* Removed unnecessary save_cpu_state() calls

v3:
* Rewrote MSA patch
* Work-around is using byte-to-byte accesses and endianness corrections for 
  R5+MSA. (This replaces the misaligned flag from v2.) (Leon)
* Bug fixes (Leon)
* Separate helper functions for each data formats

v2:
* Removed re-translation in the mips_cpu_do_unaligned_access() (Peter)
* Checks validity only if an access is spanning into two pages in MSA (Leon)
* Introduced misaligned flag to indicate MSA ld/st is ongoing, is used to
  allow misaligned accesses in the mips_cpu_do_unaligned_access() callback.
  This is crucial to support MSA misaligned accesses in Release 5 cores.

Yongbok Kim (3):
  target-mips: Misaligned memory accesses for R6
  softmmu: Add probe_write()
  target-mips: Misaligned memory accesses for MSA

 include/exec/exec-all.h      |    2 +
 softmmu_template.h           |   21 ++++++
 target-mips/helper.h         |   10 +++-
 target-mips/op_helper.c      |  144 +++++++++++++++++++++++------------------
 target-mips/translate.c      |   21 ++++--
 target-mips/translate_init.c |    2 +-
 6 files changed, 127 insertions(+), 73 deletions(-)

-- 
1.7.5.4

[Qemu-devel] [PATCH v4 1/3] target-mips: Misaligned memory accesses for R6

[Yongbok Kim]

Release 6 requires misaligned memory access support for all ordinary memory
access instructions (for example, LW/SW, LWC1/SWC1).
However misaligned support is not provided for certain special memory accesses
such as atomics (for example, LL/SC).

Allows misaligned accesses from mips_cpu_do_unaligned_access() callback,
if it is a R6 core. As the helper functions of LL/SC is checking misalignment,
just allowing all for R6 is good enough.

Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
Reviewed-by: Andreas Färber <afaerber@suse.de>
---
 target-mips/op_helper.c      |    7 +++++++
 target-mips/translate_init.c |    2 +-
 2 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
index 73a8e45..58f02cf 100644
--- a/target-mips/op_helper.c
+++ b/target-mips/op_helper.c
@@ -2215,6 +2215,13 @@ void mips_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
     int error_code = 0;
     int excp;
 
+    if (env->insn_flags & ISA_MIPS32R6) {
+        /* Release 6 provides support for misaligned memory access for
+         * all ordinary memory reference instructions
+         * */
+        return;
+    }
+
     env->CP0_BadVAddr = addr;
 
     if (access_type == MMU_DATA_STORE) {
diff --git a/target-mips/translate_init.c b/target-mips/translate_init.c
index 85a65e7..ec54fef 100644
--- a/target-mips/translate_init.c
+++ b/target-mips/translate_init.c
@@ -607,7 +607,7 @@ static const mips_def_t mips_defs[] =
     },
     {
         /* A generic CPU supporting MIPS64 Release 6 ISA.
-           FIXME: Support IEEE 754-2008 FP and misaligned memory accesses.
+           FIXME: Support IEEE 754-2008 FP.
                   Eventually this should be replaced by a real CPU model. */
         .name = "MIPS64R6-generic",
         .CP0_PRid = 0x00010000,
-- 
1.7.5.4

Re: [Qemu-devel] [PATCH v4 1/3] target-mips: Misaligned memory accesses for R6

[Richard Henderson]

On 05/20/2015 08:12 AM, Yongbok Kim wrote:
> diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
> index 73a8e45..58f02cf 100644
> --- a/target-mips/op_helper.c
> +++ b/target-mips/op_helper.c
> @@ -2215,6 +2215,13 @@ void mips_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
>      int error_code = 0;
>      int excp;
>  
> +    if (env->insn_flags & ISA_MIPS32R6) {
> +        /* Release 6 provides support for misaligned memory access for
> +         * all ordinary memory reference instructions
> +         * */
> +        return;
> +    }

This should be done instead with MO_UNALN, at translate time.
See target-ppc, DisasContext, default_tcg_memop_mask.


r~

Re: [Qemu-devel] [PATCH v4 1/3] target-mips: Misaligned memory accesses for R6

[Yongbok Kim]

On 20/05/2015 18:09, Richard Henderson wrote:
> On 05/20/2015 08:12 AM, Yongbok Kim wrote:
>> diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
>> index 73a8e45..58f02cf 100644
>> --- a/target-mips/op_helper.c
>> +++ b/target-mips/op_helper.c
>> @@ -2215,6 +2215,13 @@ void mips_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
>>      int error_code = 0;
>>      int excp;
>>  
>> +    if (env->insn_flags & ISA_MIPS32R6) {
>> +        /* Release 6 provides support for misaligned memory access for
>> +         * all ordinary memory reference instructions
>> +         * */
>> +        return;
>> +    }
> 
> This should be done instead with MO_UNALN, at translate time.
> See target-ppc, DisasContext, default_tcg_memop_mask.
> 
> 
> r~
> 

Fair enough. Actually I considered to pass the information but didn't
bother as this way is so simple.

Regards,
Yongbok

Re: [Qemu-devel] [PATCH v4 1/3] target-mips: Misaligned memory accesses for R6

[Richard Henderson]

On 05/21/2015 02:47 AM, Yongbok Kim wrote:
> Fair enough. Actually I considered to pass the information but didn't
> bother as this way is so simple.

If you ever quit relying on a separate heck for atomics,
which you probably should, this would be incorrect.


r~

[Qemu-devel] [PATCH v4 2/3] softmmu: Add probe_write()

[Yongbok Kim]

Add probe_write() forces a tlb_fill if the specified guest virtual
index isn't in the TCG softmmu TLB.

Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
---
 include/exec/exec-all.h |    2 ++
 softmmu_template.h      |   21 +++++++++++++++++++++
 2 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h
index b58cd47..af51203 100644
--- a/include/exec/exec-all.h
+++ b/include/exec/exec-all.h
@@ -109,6 +109,8 @@ void tlb_set_page_with_attrs(CPUState *cpu, target_ulong vaddr,
                              hwaddr paddr, MemTxAttrs attrs,
                              int prot, int mmu_idx, target_ulong size);
 void tb_invalidate_phys_addr(AddressSpace *as, hwaddr addr);
+void probe_write(CPUArchState *env, target_ulong addr, int mmu_idx,
+                 uintptr_t retaddr);
 #else
 static inline void tlb_flush_page(CPUState *cpu, target_ulong addr)
 {
diff --git a/softmmu_template.h b/softmmu_template.h
index 39f571b..c175d17 100644
--- a/softmmu_template.h
+++ b/softmmu_template.h
@@ -548,6 +548,27 @@ glue(glue(helper_st, SUFFIX), MMUSUFFIX)(CPUArchState *env, target_ulong addr,
     helper_te_st_name(env, addr, val, oi, GETRA());
 }
 
+#if DATA_SIZE == 1
+/*
+ * Force a tlb_fill if the specified guest virtual index isn't in the TCG
+ * softmmu TLB.
+ */
+void probe_write(CPUArchState *env, target_ulong addr, int mmu_idx,
+                 uintptr_t retaddr)
+{
+    int index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
+    target_ulong tlb_addr = env->tlb_table[mmu_idx][index].addr_write;
+
+    if ((addr & TARGET_PAGE_MASK)
+        != (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
+        /* TLB entry is for a different page */
+        if (!VICTIM_TLB_HIT(addr_write)) {
+            tlb_fill(ENV_GET_CPU(env), addr, MMU_DATA_STORE, mmu_idx, retaddr);
+        }
+    }
+    return;
+}
+#endif
 #endif /* !defined(SOFTMMU_CODE_ACCESS) */
 
 #undef READ_ACCESS_TYPE
-- 
1.7.5.4

Re: [Qemu-devel] [PATCH v4 2/3] softmmu: Add probe_write()

[Richard Henderson]

On 05/20/2015 08:12 AM, Yongbok Kim wrote:
> +    }
> +    return;
> +}

Drop the useless return.


r~

[Qemu-devel] [PATCH v4 3/3] target-mips: Misaligned memory accesses for MSA

[Yongbok Kim]

MIPS SIMD Architecture vector loads and stores require misalignment support.
MSA Memory access should work as an atomic operation. Therefore, it has to
check validity of all addresses for a vector store access if it is spanning
into two pages.

Separating helper functions for each data format as format is known in
translation.
To use mmu_idx from cpu_mmu_index() instead of calculating it from hflag.
Removing save_cpu_state() call in translation because it is able to use
cpu_restore_state() on fault as GETRA() is passed.

Signed-off-by: Yongbok Kim <yongbok.kim@imgtec.com>
---
 target-mips/helper.h    |   10 +++-
 target-mips/op_helper.c |  137 +++++++++++++++++++++++++---------------------
 target-mips/translate.c |   21 +++++---
 3 files changed, 96 insertions(+), 72 deletions(-)

diff --git a/target-mips/helper.h b/target-mips/helper.h
index 3bd0b02..c532276 100644
--- a/target-mips/helper.h
+++ b/target-mips/helper.h
@@ -931,5 +931,11 @@ DEF_HELPER_4(msa_ftint_u_df, void, env, i32, i32, i32)
 DEF_HELPER_4(msa_ffint_s_df, void, env, i32, i32, i32)
 DEF_HELPER_4(msa_ffint_u_df, void, env, i32, i32, i32)
 
-DEF_HELPER_5(msa_ld_df, void, env, i32, i32, i32, s32)
-DEF_HELPER_5(msa_st_df, void, env, i32, i32, i32, s32)
+#define MSALDST_PROTO(type)                                 \
+DEF_HELPER_4(msa_ld_ ## type, void, env, i32, i32, s32)     \
+DEF_HELPER_4(msa_st_ ## type, void, env, i32, i32, s32)
+MSALDST_PROTO(b)
+MSALDST_PROTO(h)
+MSALDST_PROTO(w)
+MSALDST_PROTO(d)
+#undef MSALDST_PROTO
diff --git a/target-mips/op_helper.c b/target-mips/op_helper.c
index 58f02cf..37667c1 100644
--- a/target-mips/op_helper.c
+++ b/target-mips/op_helper.c
@@ -3565,72 +3565,83 @@ FOP_CONDN_S(sne,  (float32_lt(fst1, fst0, &env->active_fpu.fp_status)
 /* Element-by-element access macros */
 #define DF_ELEMENTS(df) (MSA_WRLEN / DF_BITS(df))
 
-void helper_msa_ld_df(CPUMIPSState *env, uint32_t df, uint32_t wd, uint32_t rs,
-                     int32_t s10)
-{
-    wr_t *pwd = &(env->active_fpu.fpr[wd].wr);
-    target_ulong addr = env->active_tc.gpr[rs] + (s10 << df);
-    int i;
-
-    switch (df) {
-    case DF_BYTE:
-        for (i = 0; i < DF_ELEMENTS(DF_BYTE); i++) {
-            pwd->b[i] = do_lbu(env, addr + (i << DF_BYTE),
-                                env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
-    case DF_HALF:
-        for (i = 0; i < DF_ELEMENTS(DF_HALF); i++) {
-            pwd->h[i] = do_lhu(env, addr + (i << DF_HALF),
-                                env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
-    case DF_WORD:
-        for (i = 0; i < DF_ELEMENTS(DF_WORD); i++) {
-            pwd->w[i] = do_lw(env, addr + (i << DF_WORD),
-                                env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
-    case DF_DOUBLE:
-        for (i = 0; i < DF_ELEMENTS(DF_DOUBLE); i++) {
-            pwd->d[i] = do_ld(env, addr + (i << DF_DOUBLE),
-                                env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
-    }
+#define MSA_LD_DF(DF, TYPE, LD_INSN, ...)                               \
+void helper_msa_ld_ ## TYPE(CPUMIPSState *env, uint32_t wd, uint32_t rs,\
+                     int32_t s10)                                       \
+{                                                                       \
+    wr_t *pwd = &(env->active_fpu.fpr[wd].wr);                          \
+    wr_t wx;                                                            \
+    target_ulong addr = env->active_tc.gpr[rs] + (s10 << DF);           \
+    int i;                                                              \
+    for (i = 0; i < DF_ELEMENTS(DF); i++) {                             \
+        wx.TYPE[i] = LD_INSN(env, addr + (i << DF), ##__VA_ARGS__);     \
+    }                                                                   \
+    memcpy(pwd, &wx, sizeof(wr_t));                                     \
 }
 
-void helper_msa_st_df(CPUMIPSState *env, uint32_t df, uint32_t wd, uint32_t rs,
-                     int32_t s10)
+#if !defined(CONFIG_USER_ONLY)
+MSA_LD_DF(DF_BYTE,   b, helper_ret_ldub_mmu, \
+          make_memop_idx(MO_UNALN, cpu_mmu_index(env)), GETRA())
+MSA_LD_DF(DF_HALF,   h, helper_ret_lduw_mmu, \
+          make_memop_idx(MO_UNALN, cpu_mmu_index(env)), GETRA())
+MSA_LD_DF(DF_WORD,   w, helper_ret_ldul_mmu, \
+          make_memop_idx(MO_UNALN, cpu_mmu_index(env)), GETRA())
+MSA_LD_DF(DF_DOUBLE, d, helper_ret_ldq_mmu,  \
+          make_memop_idx(MO_UNALN, cpu_mmu_index(env)), GETRA())
+#else
+MSA_LD_DF(DF_BYTE,   b, cpu_ldub_data)
+MSA_LD_DF(DF_HALF,   h, cpu_lduw_data)
+MSA_LD_DF(DF_WORD,   w, cpu_ldl_data)
+MSA_LD_DF(DF_DOUBLE, d, cpu_ldq_data)
+#endif
+
+static inline void ensure_writable_pages(CPUMIPSState *env,
+                                         target_ulong addr,
+                                         int mmu_idx,
+                                         uintptr_t retaddr)
 {
-    wr_t *pwd = &(env->active_fpu.fpr[wd].wr);
-    target_ulong addr = env->active_tc.gpr[rs] + (s10 << df);
-    int i;
+#if !defined(CONFIG_USER_ONLY)
+#define MSA_PAGESPAN(x) (unlikely((((x) & ~TARGET_PAGE_MASK)                \
+                                   + MSA_WRLEN/8 - 1) >= TARGET_PAGE_SIZE))
+    target_ulong page_addr;
 
-    switch (df) {
-    case DF_BYTE:
-        for (i = 0; i < DF_ELEMENTS(DF_BYTE); i++) {
-            do_sb(env, addr + (i << DF_BYTE), pwd->b[i],
-                    env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
-    case DF_HALF:
-        for (i = 0; i < DF_ELEMENTS(DF_HALF); i++) {
-            do_sh(env, addr + (i << DF_HALF), pwd->h[i],
-                    env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
-    case DF_WORD:
-        for (i = 0; i < DF_ELEMENTS(DF_WORD); i++) {
-            do_sw(env, addr + (i << DF_WORD), pwd->w[i],
-                    env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
-    case DF_DOUBLE:
-        for (i = 0; i < DF_ELEMENTS(DF_DOUBLE); i++) {
-            do_sd(env, addr + (i << DF_DOUBLE), pwd->d[i],
-                    env->hflags & MIPS_HFLAG_KSU);
-        }
-        break;
+    if (MSA_PAGESPAN(addr)) {
+        /* first page */
+        probe_write(env, addr, mmu_idx, retaddr);
+        /* second page */
+        page_addr = (addr & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE;
+        probe_write(env, page_addr, mmu_idx, retaddr);
     }
+#endif
 }
+
+#define MSA_ST_DF(DF, TYPE, ST_INSN, ...)                               \
+void helper_msa_st_ ## TYPE(CPUMIPSState *env, uint32_t wd, uint32_t rs,\
+                     int32_t s10)                                       \
+{                                                                       \
+    wr_t *pwd = &(env->active_fpu.fpr[wd].wr);                          \
+    target_ulong addr = env->active_tc.gpr[rs] + (s10 << DF);           \
+    int mmu_idx = cpu_mmu_index(env);                                   \
+    int i;                                                              \
+    ensure_writable_pages(env, addr, mmu_idx, GETRA());                 \
+    for (i = 0; i < DF_ELEMENTS(DF); i++) {                             \
+        ST_INSN(env, addr + (i << DF), pwd->TYPE[i], ##__VA_ARGS__);    \
+    }                                                                   \
+}
+
+#if !defined(CONFIG_USER_ONLY)
+MSA_ST_DF(DF_BYTE,   b, helper_ret_stb_mmu, \
+          make_memop_idx(MO_UNALN, mmu_idx), GETRA())
+MSA_ST_DF(DF_HALF,   h, helper_ret_stw_mmu, \
+          make_memop_idx(MO_UNALN, mmu_idx), GETRA())
+MSA_ST_DF(DF_WORD,   w, helper_ret_stl_mmu, \
+          make_memop_idx(MO_UNALN, mmu_idx), GETRA())
+MSA_ST_DF(DF_DOUBLE, d, helper_ret_stq_mmu,  \
+          make_memop_idx(MO_UNALN, mmu_idx), GETRA())
+#else
+MSA_ST_DF(DF_BYTE,   b, cpu_stb_data)
+MSA_ST_DF(DF_HALF,   h, cpu_stw_data)
+MSA_ST_DF(DF_WORD,   w, cpu_stl_data)
+MSA_ST_DF(DF_DOUBLE, d, cpu_stq_data)
+#endif
+
diff --git a/target-mips/translate.c b/target-mips/translate.c
index fd063a2..88b3206 100644
--- a/target-mips/translate.c
+++ b/target-mips/translate.c
@@ -18402,32 +18402,39 @@ static void gen_msa(CPUMIPSState *env, DisasContext *ctx)
             int32_t s10 = sextract32(ctx->opcode, 16, 10);
             uint8_t rs = (ctx->opcode >> 11) & 0x1f;
             uint8_t wd = (ctx->opcode >> 6) & 0x1f;
-            uint8_t df = (ctx->opcode >> 0) & 0x3;
 
-            TCGv_i32 tdf = tcg_const_i32(df);
             TCGv_i32 twd = tcg_const_i32(wd);
             TCGv_i32 trs = tcg_const_i32(rs);
             TCGv_i32 ts10 = tcg_const_i32(s10);
 
             switch (MASK_MSA_MINOR(opcode)) {
             case OPC_LD_B:
+                gen_helper_msa_ld_b(cpu_env, twd, trs, ts10);
+                break;
             case OPC_LD_H:
+                gen_helper_msa_ld_h(cpu_env, twd, trs, ts10);
+                break;
             case OPC_LD_W:
+                gen_helper_msa_ld_w(cpu_env, twd, trs, ts10);
+                break;
             case OPC_LD_D:
-                save_cpu_state(ctx, 1);
-                gen_helper_msa_ld_df(cpu_env, tdf, twd, trs, ts10);
+                gen_helper_msa_ld_d(cpu_env, twd, trs, ts10);
                 break;
             case OPC_ST_B:
+                gen_helper_msa_st_b(cpu_env, twd, trs, ts10);
+                break;
             case OPC_ST_H:
+                gen_helper_msa_st_h(cpu_env, twd, trs, ts10);
+                break;
             case OPC_ST_W:
+                gen_helper_msa_st_w(cpu_env, twd, trs, ts10);
+                break;
             case OPC_ST_D:
-                save_cpu_state(ctx, 1);
-                gen_helper_msa_st_df(cpu_env, tdf, twd, trs, ts10);
+                gen_helper_msa_st_d(cpu_env, twd, trs, ts10);
                 break;
             }
 
             tcg_temp_free_i32(twd);
-            tcg_temp_free_i32(tdf);
             tcg_temp_free_i32(trs);
             tcg_temp_free_i32(ts10);
         }
-- 
1.7.5.4

Re: [Qemu-devel] [PATCH v4 3/3] target-mips: Misaligned memory accesses for MSA

[Richard Henderson]

On 05/20/2015 08:12 AM, Yongbok Kim wrote:
> +#define MSA_LD_DF(DF, TYPE, LD_INSN, ...)                               \
> +void helper_msa_ld_ ## TYPE(CPUMIPSState *env, uint32_t wd, uint32_t rs,\
> +                     int32_t s10)                                       \
> +{                                                                       \
> +    wr_t *pwd = &(env->active_fpu.fpr[wd].wr);                          \
> +    wr_t wx;                                                            \
> +    target_ulong addr = env->active_tc.gpr[rs] + (s10 << DF);           \

It would be nice to clean this up a bit more.  For instance, don't pass the
register number and offset.  Instead, compute the address properly during
translation and pass that down.

> +    int i;                                                              \
> +    for (i = 0; i < DF_ELEMENTS(DF); i++) {                             \
> +        wx.TYPE[i] = LD_INSN(env, addr + (i << DF), ##__VA_ARGS__);     \

Why the varargs?  They're the same all the time.

> +MSA_LD_DF(DF_BYTE,   b, helper_ret_ldub_mmu, \
> +          make_memop_idx(MO_UNALN, cpu_mmu_index(env)), GETRA())

I would prefer it if you'd pass the full and proper TCGMemOp.
I.e. MO_TE | MO_{8,16,32,64} | MO_UNALN.

And you might as well hoist that out of the load/store loops.


r~

Re: [Qemu-devel] [PATCH v4 3/3] target-mips: Misaligned memory accesses for MSA

[Yongbok Kim]

On 20/05/2015 18:25, Richard Henderson wrote:

> 
>> +    int i;                                                              \
>> +    for (i = 0; i < DF_ELEMENTS(DF); i++) {                             \
>> +        wx.TYPE[i] = LD_INSN(env, addr + (i << DF), ##__VA_ARGS__);     \
> 
> Why the varargs?  They're the same all the time.

No, they aren't. we still need to support linux user mode which don't have
any extra argument.

MSA_LD_DF(DF_BYTE,   b, helper_ret_ldub_mmu, \
          make_memop_idx(MO_UNALN, cpu_mmu_index(env)), GETRA())

VS.

MSA_LD_DF(DF_BYTE,   b, cpu_ldub_data)


Regards,
Yongbok

Re: [Qemu-devel] [PATCH v4 3/3] target-mips: Misaligned memory accesses for MSA

[Richard Henderson]

On 05/21/2015 02:47 AM, Yongbok Kim wrote:
> On 20/05/2015 18:25, Richard Henderson wrote:
> 
>>
>>> +    int i;                                                              \
>>> +    for (i = 0; i < DF_ELEMENTS(DF); i++) {                             \
>>> +        wx.TYPE[i] = LD_INSN(env, addr + (i << DF), ##__VA_ARGS__);     \
>>
>> Why the varargs?  They're the same all the time.
> 
> No, they aren't. we still need to support linux user mode which don't have
> any extra argument.
> 
> MSA_LD_DF(DF_BYTE,   b, helper_ret_ldub_mmu, \
>           make_memop_idx(MO_UNALN, cpu_mmu_index(env)), GETRA())
> 
> VS.
> 
> MSA_LD_DF(DF_BYTE,   b, cpu_ldub_data)

Ah, I'd missed that.  Thanks,


r~