On 12-09-28 4:07 PM, Jeff Law wrote:
On 09/27/2012 04:58 PM, Vladimir Makarov wrote:
The following patch modifies some code in the rest of compiler for
correct work of LRA. The code works the same way when LRA is not
used. It is achieved by checking a new variable lra_in_progress.
2012-09-27 Vladimir Makarov <vmaka...@redhat.com>
* rtlanal.c (simplify_subreg_regno): Permit ARG_POINTER_REGNUM and
STACK_POINTER_REGNU for LRA.
* jump.c (true_regnum): Always use hard_regno for
subreg_get_info when
lra is in progress.
* expr.c (emit_move_insn_1): Pass an additional argument to
emit_move_via_integer. Use emit_move_via_integer for LRA only if
the insn is recognized.
* recog.c (general_operand, register_operand): Accept paradoxical
FLOAD_MODE
subregs for LRA.
(scratch_operand): Accept pseudos for LRA.
* emit-rtl.c (gen_rtx_REG): Add lra_in_progress.
(validate_subreg): Don't check offset for LRA and
floating point modes.
* rtl.h (lra_in_progress): New external.
* ira.c (lra_in_progress): Define.
s/FLOAD/FLOAT/ to fix ChangeLog typo.
Thanks. I fixed it will be in the revised versions of the patches.
Index: jump.c
===================================================================
--- jump.c (revision 191771)
+++ jump.c (working copy)
@@ -1868,7 +1868,8 @@ true_regnum (const_rtx x)
{
if (REG_P (x))
{
- if (REGNO (x) >= FIRST_PSEUDO_REGISTER && reg_renumber[REGNO
(x)] >= 0)
+ if (REGNO (x) >= FIRST_PSEUDO_REGISTER
+ && (lra_in_progress || reg_renumber[REGNO (x)] >= 0))
return reg_renumber[REGNO (x)];
return REGNO (x);
}
This hunk doesn't make any sense to me, unless you want true_regnum to
return a negative value during LRA for cases where the pseudo is still
unassigned. Is that what's you're intending here? If that's what you
want, then I think it's worth a quick comment.
Yes, that was my intention. LRA works a bit different from reload. It
needs the current assignment of pseudos (assigned hard register or -1
even it is not assigned).
I'll add the comment about this in the next version of the patch. The
code looks a bit strange and could be more clear but I kept in my mind
removing code for reload in the future.
@@ -1880,7 +1881,8 @@ true_regnum (const_rtx x)
{
struct subreg_info info;
- subreg_get_info (REGNO (SUBREG_REG (x)),
+ subreg_get_info (lra_in_progress
+ ? (unsigned) base : REGNO (SUBREG_REG (x)),
GET_MODE (SUBREG_REG (x)),
SUBREG_BYTE (x), GET_MODE (x), &info);
I'd be good to indicate why you want to do something different for LRA
here.
I need to know the current allocation with taking into account that the
subregister with final hard register will be representable. I'll add the
comment.
Index: rtlanal.c
===================================================================
--- rtlanal.c (revision 191771)
+++ rtlanal.c (working copy)
@@ -3465,7 +3465,9 @@ simplify_subreg_regno (unsigned int xreg
/* Give the backend a chance to disallow the mode change. */
if (GET_MODE_CLASS (xmode) != MODE_COMPLEX_INT
&& GET_MODE_CLASS (xmode) != MODE_COMPLEX_FLOAT
- && REG_CANNOT_CHANGE_MODE_P (xregno, xmode, ymode))
+ && REG_CANNOT_CHANGE_MODE_P (xregno, xmode, ymode)
+ /* We can use mode change in LRA for some transformations. */
+ && ! lra_in_progress)
return -1;
#endif
I don't think this change is reflected in the ChangeLog.
You are right. I added the change description in the ChangeLog. Reload
has no problem in representation of some decisions because it uses
internal representation. It is a problem for LRA using RTL when for
example two insn operands in different modes should have the same hard
register according to the constraint. I use subreg for that even it is
not a correct in other parts of the compiler.
I think just the minor ChangeLog updates and clarification of the
changes to jump.c are all that's needed for this patch to be approved.
Thanks, Jeff. I really appreciate your help.
