Re: [trans-mem] optimize transaction local malloc/alloca memory

[Richard Henderson <rth at redhat dot com>]

On 12/04/2009 06:26 AM, Aldy Hernandez wrote:
> +  p = malloc (sizeof (*p) * 100);
> +
> +  __transaction {
> +    /* Instrument store, since memory pointed to by P is not
> +       transaction local.  */
> +    p[5] = 123;
> +
> +    if (something())
> +      __transaction_cancel;
> +  }
> +  return p[5];
> +}
> +
> +/* { dg-final { scan-tree-dump-times "ITM_WU" 1 "tmmark" } } */

Not the best test case to add, since P is thread-private. You could 
instrument this with either a log function or a local copy.

> +  if (stmt&&  is_gimple_call (stmt))

Formatting.

> +      if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL
> +	&&  (DECL_FUNCTION_CODE (fn) == BUILT_IN_MALLOC
> +	      || DECL_FUNCTION_CODE (fn) == BUILT_IN_ALLOCA))

gimple_call_flags (stmt) & ECF_MALLOC

> @@ -1149,6 +1219,8 @@ requires_barrier (basic_block entry_bloc
>     switch (TREE_CODE (x))
>       {
>       case INDIRECT_REF:
> +      if (transaction_local_dynamic_memory_p (entry_block, TREE_OPERAND (x, 0)))
> +	return false;

You're going to do the whole walking and analysis thing for every memory 
reference?  I could imagine it'd be a lot better to cache this data so 
that in the next statement, which might well also use the same base 
SSA_NAME, doesn't have to re-do the analysis.


r~