* Re: [Qemu-devel] [PATCH] softmmu_template: POC simpler do_unl_access inline
2016-01-07 15:10 ` [Qemu-devel] [PATCH] softmmu_template: POC simpler do_unl_access inline Alex Bennée
@ 2016-01-07 15:21 ` alvise rigo
0 siblings, 0 replies; 2+ messages in thread
From: alvise rigo @ 2016-01-07 15:21 UTC (permalink / raw)
To: Alex Bennée
Cc: mttcg, Peter Crosthwaite, Mark Burton, QEMU Developers,
Paolo Bonzini, Richard Henderson, KONRAD Frédéric
On Thu, Jan 7, 2016 at 4:10 PM, Alex Bennée <alex.bennee@linaro.org> wrote:
> As any constant arguments will be folded by the compiler when a function
I don't understand. If I look at a preprocessed cputlb.c file, I can
see both the le and be variants of the helpers.
Given this, how can little_endian be a constant?
alvise
> is in-lined we can squash the be/le handlers together and let the
> compiler figure it out.
> ---
> softmmu_template.h | 68 ++++++++++++++++++++----------------------------------
> 1 file changed, 25 insertions(+), 43 deletions(-)
>
> diff --git a/softmmu_template.h b/softmmu_template.h
> index 65cce0a..6d86a21 100644
> --- a/softmmu_template.h
> +++ b/softmmu_template.h
> @@ -108,6 +108,8 @@
> # define helper_be_st_name glue(glue(helper_be_st, SUFFIX), MMUSUFFIX)
> #endif
>
> +#define helper_generic_st_name glue(glue(helper_generic_st, SUFFIX), MMUSUFFIX)
> +
> #ifdef TARGET_WORDS_BIGENDIAN
> # define helper_te_ld_name helper_be_ld_name
> # define helper_te_st_name helper_be_st_name
> @@ -378,12 +380,13 @@ static inline void glue(io_write, SUFFIX)(CPUArchState *env,
> iotlbentry->attrs);
> }
>
> -static inline void glue(helper_le_st_name, _do_unl_access)(CPUArchState *env,
> - DATA_TYPE val,
> - target_ulong addr,
> - TCGMemOpIdx oi,
> - unsigned mmu_idx,
> - uintptr_t retaddr)
> +static inline void glue(helper_generic_st_name, _do_unl_access)(CPUArchState *env,
> + bool little_endian,
> + DATA_TYPE val,
> + target_ulong addr,
> + TCGMemOpIdx oi,
> + unsigned mmu_idx,
> + uintptr_t retaddr)
> {
> int i;
>
> @@ -391,12 +394,17 @@ static inline void glue(helper_le_st_name, _do_unl_access)(CPUArchState *env,
> cpu_unaligned_access(ENV_GET_CPU(env), addr, MMU_DATA_STORE,
> mmu_idx, retaddr);
> }
> - /* XXX: not efficient, but simple */
> /* Note: relies on the fact that tlb_fill() does not remove the
> * previous page from the TLB cache. */
> for (i = DATA_SIZE - 1; i >= 0; i--) {
> - /* Little-endian extract. */
> - uint8_t val8 = val >> (i * 8);
> + uint8_t val8;
> + if (little_endian) {
> + /* Little-endian extract. */
> + val8 = val >> (i * 8);
> + } else {
> + /* Big-endian extract. */
> + val8 = val >> (((DATA_SIZE - 1) * 8) - (i * 8));
> + }
> /* Note the adjustment at the beginning of the function.
> Undo that for the recursion. */
> glue(helper_ret_stb, MMUSUFFIX)(env, addr + i, val8,
> @@ -415,8 +423,8 @@ static inline void glue(helper_le_st_name, _do_mmio_access)(CPUArchState *env,
> CPUIOTLBEntry *iotlbentry = &env->iotlb[mmu_idx][index];
>
> if ((addr & (DATA_SIZE - 1)) != 0) {
> - glue(helper_le_st_name, _do_unl_access)(env, val, addr, mmu_idx,
> - oi, retaddr);
> + glue(helper_generic_st_name, _do_unl_access)(env, true, val, addr,
> + mmu_idx, oi, retaddr);
> }
> /* ??? Note that the io helpers always read data in the target
> byte ordering. We should push the LE/BE request down into io. */
> @@ -438,8 +446,8 @@ static inline void glue(helper_le_st_name, _do_ram_access)(CPUArchState *env,
> if (DATA_SIZE > 1
> && unlikely((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1
> >= TARGET_PAGE_SIZE)) {
> - glue(helper_le_st_name, _do_unl_access)(env, val, addr, oi, mmu_idx,
> - retaddr);
> + glue(helper_generic_st_name, _do_unl_access)(env, true, val, addr, oi, mmu_idx,
> + retaddr);
> return;
> }
>
> @@ -538,32 +546,6 @@ void helper_le_st_name(CPUArchState *env, target_ulong addr, DATA_TYPE val,
> }
>
> #if DATA_SIZE > 1
> -static inline void glue(helper_be_st_name, _do_unl_access)(CPUArchState *env,
> - DATA_TYPE val,
> - target_ulong addr,
> - TCGMemOpIdx oi,
> - unsigned mmu_idx,
> - uintptr_t retaddr)
> -{
> - int i;
> -
> - if ((get_memop(oi) & MO_AMASK) == MO_ALIGN) {
> - cpu_unaligned_access(ENV_GET_CPU(env), addr, MMU_DATA_STORE,
> - mmu_idx, retaddr);
> - }
> - /* XXX: not efficient, but simple */
> - /* Note: relies on the fact that tlb_fill() does not remove the
> - * previous page from the TLB cache. */
> - for (i = DATA_SIZE - 1; i >= 0; i--) {
> - /* Big-endian extract. */
> - uint8_t val8 = val >> (((DATA_SIZE - 1) * 8) - (i * 8));
> - /* Note the adjustment at the beginning of the function.
> - Undo that for the recursion. */
> - glue(helper_ret_stb, MMUSUFFIX)(env, addr + i, val8,
> - oi, retaddr + GETPC_ADJ);
> - }
> -}
> -
> static inline void glue(helper_be_st_name, _do_mmio_access)(CPUArchState *env,
> DATA_TYPE val,
> target_ulong addr,
> @@ -575,8 +557,8 @@ static inline void glue(helper_be_st_name, _do_mmio_access)(CPUArchState *env,
> CPUIOTLBEntry *iotlbentry = &env->iotlb[mmu_idx][index];
>
> if ((addr & (DATA_SIZE - 1)) != 0) {
> - glue(helper_be_st_name, _do_unl_access)(env, val, addr, mmu_idx,
> - oi, retaddr);
> + glue(helper_generic_st_name, _do_unl_access)(env, false, val, addr, mmu_idx,
> + oi, retaddr);
> }
> /* ??? Note that the io helpers always read data in the target
> byte ordering. We should push the LE/BE request down into io. */
> @@ -598,8 +580,8 @@ static inline void glue(helper_be_st_name, _do_ram_access)(CPUArchState *env,
> if (DATA_SIZE > 1
> && unlikely((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1
> >= TARGET_PAGE_SIZE)) {
> - glue(helper_be_st_name, _do_unl_access)(env, val, addr, oi, mmu_idx,
> - retaddr);
> + glue(helper_generic_st_name, _do_unl_access)(env, false, val, addr, oi, mmu_idx,
> + retaddr);
> return;
> }
>
> --
> 2.6.4
>
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