Richard Henderson <r...@twiddle.net> writes:
> This avoids needing to test the index of a temp against nb_globals.
>
> Signed-off-by: Richard Henderson <r...@twiddle.net>
> ---
> tcg/optimize.c | 15 ++++++++-------
> tcg/tcg.c | 11 ++++++++---
> tcg/tcg.h | 12 ++++++++----
> 3 files changed, 24 insertions(+), 14 deletions(-)
>
> diff --git a/tcg/optimize.c b/tcg/optimize.c
> index d8c3a7e..55f9e83 100644
> --- a/tcg/optimize.c
> +++ b/tcg/optimize.c
> @@ -116,25 +116,26 @@ static TCGOpcode op_to_movi(TCGOpcode op)
> }
> }
>
> -static TCGArg find_better_copy(TCGContext *s, TCGArg temp)
> +static TCGArg find_better_copy(TCGContext *s, TCGArg arg)
> {
> + TCGTemp *ts = arg_temp(arg);
> TCGArg i;
>
> /* If this is already a global, we can't do better. */
> - if (temp < s->nb_globals) {
> - return temp;
> + if (ts->temp_global) {
> + return arg;
> }
>
> /* Search for a global first. */
> - for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy) {
> + for (i = temps[arg].next_copy ; i != arg; i = temps[i].next_copy) {
> if (i < s->nb_globals) {
> return i;
> }
> }
>
> /* If it is a temp, search for a temp local. */
> - if (!arg_temp(temp)->temp_local) {
> - for (i = temps[temp].next_copy ; i != temp ; i = temps[i].next_copy)
> {
> + if (!ts->temp_local) {
> + for (i = temps[arg].next_copy ; i != arg; i = temps[i].next_copy) {
> if (s->temps[i].temp_local) {
> return i;
> }
> @@ -142,7 +143,7 @@ static TCGArg find_better_copy(TCGContext *s, TCGArg temp)
> }
>
> /* Failure to find a better representation, return the same temp. */
> - return temp;
> + return arg;
> }
>
> static bool temps_are_copies(TCGArg arg1, TCGArg arg2)
> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index 068ac51..0bb88b1 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -489,9 +489,14 @@ static inline TCGTemp *tcg_temp_alloc(TCGContext *s)
>
> static inline TCGTemp *tcg_global_alloc(TCGContext *s)
> {
> + TCGTemp *ts;
> +
> tcg_debug_assert(s->nb_globals == s->nb_temps);
> s->nb_globals++;
> - return tcg_temp_alloc(s);
> + ts = tcg_temp_alloc(s);
> + ts->temp_global = 1;
> +
> + return ts;
> }
>
> static int tcg_global_reg_new_internal(TCGContext *s, TCGType type,
> @@ -967,7 +972,7 @@ static char *tcg_get_arg_str_ptr(TCGContext *s, char
> *buf, int buf_size,
> {
> int idx = temp_idx(s, ts);
>
> - if (idx < s->nb_globals) {
> + if (ts->temp_global) {
> pstrcpy(buf, buf_size, ts->name);
> } else if (ts->temp_local) {
> snprintf(buf, buf_size, "loc%d", idx - s->nb_globals);
> @@ -1905,7 +1910,7 @@ static void temp_free_or_dead(TCGContext *s, TCGTemp
> *ts, int free_or_dead)
> }
> ts->val_type = (free_or_dead < 0
> || ts->temp_local
> - || temp_idx(s, ts) < s->nb_globals
> + || ts->temp_global
> ? TEMP_VAL_MEM : TEMP_VAL_DEAD);
> }
>
> diff --git a/tcg/tcg.h b/tcg/tcg.h
> index 70d9fda..3b35344 100644
> --- a/tcg/tcg.h
> +++ b/tcg/tcg.h
> @@ -586,10 +586,14 @@ typedef struct TCGTemp {
> unsigned int indirect_base:1;
> unsigned int mem_coherent:1;
> unsigned int mem_allocated:1;
> - unsigned int temp_local:1; /* If true, the temp is saved across
> - basic blocks. Otherwise, it is not
> - preserved across basic blocks. */
> - unsigned int temp_allocated:1; /* never used for code gen */
> + /* If true, the temp is saved across both basic blocks and
> + translation blocks. */
> + unsigned int temp_global:1;
> + /* If true, the temp is saved across basic blocks but dead
> + at the end of translation blocks. If false, the temp is
> + dead at the end of basic blocks. */
> + unsigned int temp_local:1;
> + unsigned int temp_allocated:1;
This is where my knowledge of the TCG internals gets slightly confused.
As far as I'm aware all our TranslationBlocks are Basic Blocks - they
don't have any branches until the end of the block. What is the
distinction here?
Is a temp_global truly global? I thought the guest state was fully
rectified by the time we leave the basic block.
>
> tcg_target_long val;
> struct TCGTemp *mem_base;
--
Alex Bennée
