Eric Botcazou
Eric Botcazou
parent
de696511fe
commit
2426d8dd9e
|
|
@ -1,3 +1,7 @@
|
|||
2003-10-21 Eric Botcazou <ebotcazou@libertysurf.fr>
|
||||
|
||||
* web.c: Fix various comments.
|
||||
|
||||
2003-10-20 Nicolas Pitre <nico@cam.org>
|
||||
|
||||
* config/arm/arm.c (arm_override_options): Set arm_constant_limit
|
||||
|
|
|
|||
72
gcc/web.c
72
gcc/web.c
|
|
@ -1,5 +1,5 @@
|
|||
/* Web construction code for GNU compiler.
|
||||
Contributed by Jan Hubicka
|
||||
Contributed by Jan Hubicka.
|
||||
Copyright (C) 2001, 2002 Free Software Foundation, Inc.
|
||||
|
||||
This file is part of GCC.
|
||||
|
|
@ -19,28 +19,28 @@ along with GCC; see the file COPYING. If not, write to the Free
|
|||
Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
||||
02111-1307, USA. */
|
||||
|
||||
/* Simple optimization pass that splits indepdendent uses of each pseudo
|
||||
/* Simple optimization pass that splits independent uses of each pseudo,
|
||||
increasing effectivity of other optimizations. The optimization can
|
||||
serve as an example of the use of dataflow module.
|
||||
serve as an example of use for the dataflow module.
|
||||
|
||||
We don't split registers with REG_USERVAR set unless -fmessy-debugging is
|
||||
used, because debug information about such split variables is almost
|
||||
useless.
|
||||
We don't split registers with REG_USERVAR set unless -fmessy-debugging
|
||||
is specified, because debugging information about such split variables
|
||||
is almost unusable.
|
||||
|
||||
TODO
|
||||
- Add code to keep debugging up-to-date after splitting of user variable
|
||||
pseudos. This can be done by remembering all the pseudos used for the
|
||||
variable and use life analysis information before reload to determing
|
||||
wich one of the possible choices is alive and in case more are live,
|
||||
choose one with latest definition.
|
||||
- Add code to keep debugging up-to-date after splitting user variable
|
||||
pseudos. This can be done by keeping track of all the pseudos used
|
||||
for the variable and using life analysis information before reload
|
||||
to determine which one is live and, in case more than one are live,
|
||||
choose the one with the latest definition.
|
||||
|
||||
Some other optimization passes will benefit from the infrastructure
|
||||
too.
|
||||
Other optimization passes can benefit from the infrastructure too.
|
||||
|
||||
- We may use profile information and ignore infrequent use for purposes
|
||||
of web unifying inserting the compensation code later to implement full
|
||||
induction variable expansion for loops (currently we expand only if
|
||||
induction is dead afterwards, that is often the case anyway). */
|
||||
- We may use profile information and ignore infrequent use for the
|
||||
purpose of web unifying, inserting the compensation code later to
|
||||
implement full induction variable expansion for loops (currently
|
||||
we expand only if the induction variable is dead afterward, which
|
||||
is often the case). */
|
||||
|
||||
#include "config.h"
|
||||
#include "system.h"
|
||||
|
|
@ -60,9 +60,9 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
|
|||
/* This entry is allocated for each reference in the insn stream. */
|
||||
struct web_entry
|
||||
{
|
||||
/* pointer to the parent in the union/find tree. */
|
||||
/* Pointer to the parent in the union/find tree. */
|
||||
struct web_entry *pred;
|
||||
/* Newly assigned register to the entry. Set only for roots. */
|
||||
/* Newly assigned register to the entry. Set only for roots. */
|
||||
rtx reg;
|
||||
};
|
||||
|
||||
|
|
@ -77,7 +77,7 @@ static rtx entry_register PARAMS ((struct web_entry *,
|
|||
static void replace_ref PARAMS ((struct ref *, rtx));
|
||||
static int mark_addressof PARAMS ((rtx *, void *));
|
||||
|
||||
/* Find the root of unionfind tree (the representatnt of set). */
|
||||
/* Find the root of unionfind tree (the representative of set). */
|
||||
|
||||
static struct web_entry *
|
||||
unionfind_root (element)
|
||||
|
|
@ -109,8 +109,8 @@ unionfind_union (first, second)
|
|||
second->pred = first;
|
||||
}
|
||||
|
||||
/* For each use, all possible defs reaching it must come in same register,
|
||||
union them. */
|
||||
/* For each use, all possible defs reaching it must come in the same
|
||||
register, union them. */
|
||||
|
||||
static void
|
||||
union_defs (df, use, def_entry, use_entry)
|
||||
|
|
@ -125,9 +125,9 @@ union_defs (df, use, def_entry, use_entry)
|
|||
struct df_link *def_link = DF_INSN_DEFS (df, insn);
|
||||
rtx set = single_set (insn);
|
||||
|
||||
/* Some instructions may use match_dup for it's operands. In case the
|
||||
operands are dead, we will assign them different pseudos creating
|
||||
invalid instruction, so union all uses of the same operands for each
|
||||
/* Some instructions may use match_dup for their operands. In case the
|
||||
operands are dead, we will assign them different pseudos, creating
|
||||
invalid instructions, so union all uses of the same operand for each
|
||||
insn. */
|
||||
|
||||
while (use_link)
|
||||
|
|
@ -139,9 +139,9 @@ union_defs (df, use, def_entry, use_entry)
|
|||
use_link = use_link->next;
|
||||
}
|
||||
|
||||
/* Recognize trivial noop moves and attempt to keep them noop.
|
||||
While most of noop moves should be removed we still keep some at
|
||||
libcall boundaries and such. */
|
||||
/* Recognize trivial noop moves and attempt to keep them as noop.
|
||||
While most of noop moves should be removed, we still keep some
|
||||
of them at libcall boundaries and such. */
|
||||
|
||||
if (set
|
||||
&& SET_SRC (set) == DF_REF_REG (use)
|
||||
|
|
@ -162,7 +162,7 @@ union_defs (df, use, def_entry, use_entry)
|
|||
link = link->next;
|
||||
}
|
||||
|
||||
/* An READ_WRITE use require the corresponding def to be in the same
|
||||
/* A READ_WRITE use requires the corresponding def to be in the same
|
||||
register. Find it and union. */
|
||||
if (use->flags & DF_REF_READ_WRITE)
|
||||
{
|
||||
|
|
@ -176,7 +176,7 @@ union_defs (df, use, def_entry, use_entry)
|
|||
}
|
||||
}
|
||||
|
||||
/* Find corresponding register for given entry. */
|
||||
/* Find the corresponding register for the given entry. */
|
||||
|
||||
static rtx
|
||||
entry_register (entry, ref, used, use_addressof)
|
||||
|
|
@ -188,14 +188,12 @@ entry_register (entry, ref, used, use_addressof)
|
|||
struct web_entry *root;
|
||||
rtx reg, newreg;
|
||||
|
||||
/* Find corresponding web and see if it has been visited. */
|
||||
|
||||
/* Find the corresponding web and see if it has been visited. */
|
||||
root = unionfind_root (entry);
|
||||
if (root->reg)
|
||||
return root->reg;
|
||||
|
||||
/* We are seeing this web first time, do the assignment. */
|
||||
|
||||
/* We are seeing this web for the first time, do the assignment. */
|
||||
reg = DF_REF_REAL_REG (ref);
|
||||
|
||||
/* In case the original register is already assigned, generate new one. */
|
||||
|
|
@ -252,7 +250,7 @@ replace_ref (ref, reg)
|
|||
*loc = reg;
|
||||
}
|
||||
|
||||
/* Mark each pseudo, whose address is taken. */
|
||||
/* Mark each pseudo whose address is taken. */
|
||||
|
||||
static int
|
||||
mark_addressof (rtl, data)
|
||||
|
|
@ -312,8 +310,8 @@ web_main ()
|
|||
replace_ref (df->defs[i], entry_register (def_entry + i, df->defs[i],
|
||||
used, use_addressof));
|
||||
|
||||
/* Dataflow information is corrupt here, but it can be easy to update it
|
||||
by creating new entries for new registers and update or calilng
|
||||
/* Dataflow information is corrupt here, but it can be easily updated
|
||||
by creating new entries for new registers and updates or calling
|
||||
df_insns_modify. */
|
||||
free (def_entry);
|
||||
free (use_entry);
|
||||
|
|
|
|||
Loading…
Reference in New Issue