bitmap gen = bb_info->gen;
bitmap kill = bb_info->kill;
- /* We need to use a scratch set here so that the value returned from
- this function invocation properly reflects if the sets changed in
- a significant way; i.e. not just because the lr set was anded
- in. */
+ /* We need to use a scratch set here so that the value returned from this
+ function invocation properly reflects whether the sets changed in a
+ significant way; i.e. not just because the lr set was anded in. */
bitmap_and (df_live_scratch, gen, bb_lr_info->out);
/* No register may reach a location where it is not used. Thus
we trim the rr result to the places where it is used. */
MULTIPLE DEFINITIONS
Find the locations in the function reached by multiple definition sites
- for a pseudo. In and out bitvectors are built for each basic
- block.
+ for a live pseudo. In and out bitvectors are built for each basic
+ block. They are restricted for efficiency to live registers.
The gen and kill sets for the problem are obvious. Together they
include all defined registers in a basic block; the gen set includes
propagating the information to BB3's successors.
---------------------------------------------------------------------------*/
+/* Scratch var used by transfer functions. This is used to do md analysis
+ only for live registers. */
+static bitmap df_md_scratch;
+
/* Set basic block info. */
static void
sizeof (struct df_md_bb_info), 50);
df_grow_bb_info (df_md);
+ df_md_scratch = BITMAP_ALLOC (NULL);
EXECUTE_IF_SET_IN_BITMAP (all_blocks, 0, bb_index, bi)
{
bitmap kill = df_md_get_bb_info (bb_index)->kill;
EXECUTE_IF_SET_IN_BITMAP (frontiers[bb_index], 0, df_bb_index, bi2)
{
+ basic_block bb = BASIC_BLOCK (df_bb_index);
if (bitmap_bit_p (all_blocks, df_bb_index))
- bitmap_ior_into (df_md_get_bb_info (df_bb_index)->init, kill);
+ bitmap_ior_and_into (df_md_get_bb_info (df_bb_index)->init, kill,
+ df_get_live_in (bb));
}
}
static bool
df_md_transfer_function (int bb_index)
{
+ basic_block bb = BASIC_BLOCK (bb_index);
struct df_md_bb_info *bb_info = df_md_get_bb_info (bb_index);
bitmap in = bb_info->in;
bitmap out = bb_info->out;
bitmap gen = bb_info->gen;
bitmap kill = bb_info->kill;
- return bitmap_ior_and_compl (out, gen, in, kill);
+ /* We need to use a scratch set here so that the value returned from this
+ function invocation properly reflects whether the sets changed in a
+ significant way; i.e. not just because the live set was anded in. */
+ bitmap_and (df_md_scratch, gen, df_get_live_out (bb));
+
+ /* Multiple definitions of a register are not relevant if it is not
+ live. Thus we trim the result to the places where it is live. */
+ bitmap_and_into (in, df_get_live_in (bb));
+
+ return bitmap_ior_and_compl (out, df_md_scratch, in, kill);
}
/* Initialize the solution bit vectors for problem. */
}
}
+ BITMAP_FREE (df_md_scratch);
free_alloc_pool (df_md->block_pool);
df_md->block_info_size = 0;