This is one more version of the patch to fix the PR59535
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59535
Here are the results of applying the patch:
Thumb Thumb2
reload 2626334 2400154
lra (before the patch) 2665749 2414926
lra (after the patch) 2626334 2397132
I already wrote that the change in arm.h is to prevent reloading sp as
an address by LRA. Reload has no such problem as it uses legitimate
address hook and LRA mostly relies on base_reg_class.
Richard, I need an approval for this change.
2014-02-11 Vladimir Makarov <[email protected]>
PR rtl-optimization/59535
* lra-constraints.c (process_alt_operands): Encourage alternative
when unassigned pseudo class is superset of the alternative class.
(inherit_reload_reg): Don't inherit when optimizing for code size.
* config/arm/arm.h (MODE_BASE_REG_CLASS): Return CORE_REGS for
Thumb2 and BASE_REGS for modes not less than 4 for LRA.
Index: lra-constraints.c
===================================================================
--- lra-constraints.c (revision 207562)
+++ lra-constraints.c (working copy)
@@ -2112,6 +2112,21 @@ process_alt_operands (int only_alternati
goto fail;
}
+ /* If not assigned pseudo has a class which a subset of
+ required reg class, it is a less costly alternative
+ as the pseudo still can get a hard reg of necessary
+ class. */
+ if (! no_regs_p && REG_P (op) && hard_regno[nop] < 0
+ && (cl = get_reg_class (REGNO (op))) != NO_REGS
+ && ira_class_subset_p[this_alternative][cl])
+ {
+ if (lra_dump_file != NULL)
+ fprintf
+ (lra_dump_file,
+ " %d Super set class reg: reject-=3\n", nop);
+ reject -= 3;
+ }
+
this_alternative_offmemok = offmemok;
if (this_costly_alternative != NO_REGS)
{
@@ -4391,6 +4406,9 @@ static bool
inherit_reload_reg (bool def_p, int original_regno,
enum reg_class cl, rtx insn, rtx next_usage_insns)
{
+ if (optimize_function_for_size_p (cfun))
+ return false;
+
enum reg_class rclass = lra_get_allocno_class (original_regno);
rtx original_reg = regno_reg_rtx[original_regno];
rtx new_reg, new_insns, usage_insn;
Index: config/arm/arm.h
===================================================================
--- config/arm/arm.h (revision 207562)
+++ config/arm/arm.h (working copy)
@@ -1272,8 +1272,10 @@ enum reg_class
when addressing quantities in QI or HI mode; if we don't know the
mode, then we must be conservative. */
#define MODE_BASE_REG_CLASS(MODE) \
- (TARGET_ARM || (TARGET_THUMB2 && !optimize_size) ? CORE_REGS : \
- (((MODE) == SImode) ? BASE_REGS : LO_REGS))
+ (TARGET_ARM || (TARGET_THUMB2 && (!optimize_size || arm_lra_flag)) \
+ ? CORE_REGS : ((MODE) == SImode \
+ || (arm_lra_flag && GET_MODE_SIZE (MODE) >= 4) \
+ ? BASE_REGS : LO_REGS))
/* For Thumb we can not support SP+reg addressing, so we return LO_REGS
instead of BASE_REGS. */
