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CRIS regclass update, fixing build breakage
- From: Hans-Peter Nilsson <hans-peter dot nilsson at axis dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Fri, 10 Jun 2011 02:08:00 +0200
- Subject: CRIS regclass update, fixing build breakage
Updating register classes so that the narrowest class for the
SRP register is now a singleton class, instead of having other
register members without means to move to/from SRP cheaper than
memory, matching the documentation update. Also fixing the
buglet of not fixing the condition-code-register, ehm. (Not
that there could be moves for anything but CCmode to or from it,
which is useless anyway for a CC0 port.) All-in-all, together
with the ira-costs.c patch just committed, unbreaking build for
cris-elf with results at patched r174780 similar to those of
r174114 before the breakage, just adding a libstdc++ SEGV for
20_util/is_nothrow_copy_assignable/value.cc; a regression which
seems unrelated anyway -save-temps makes it go away. Committed.
PR rtl-optimization/49154
* config/cris/cris.h (FIXED_REGISTERS): Include CRIS_CC0_REGNUM.
(enum reg_class): Add SRP_REGS and MOF_SRP_REGS.
(REG_CLASS_NAMES, REG_CLASS_CONTENTS, REGNO_REG_CLASS)
(PREFERRED_RELOAD_CLASS, SECONDARY_RELOAD_CLASS): Adjust to fit.
* config/cris/cris.h (cris_register_move_cost): Remove
!TARGET_V32 code. Tweak comments.
diff --git gcc/config/cris/cris.c gcc/config/cris/cris.c
index 110e985..159b31b 100644
--- gcc/config/cris/cris.c
+++ gcc/config/cris/cris.c
@@ -1360,24 +1360,11 @@ static int
cris_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
reg_class_t from, reg_class_t to)
{
- if (!TARGET_V32)
- {
- /* Pretend that classes that we don't support are ALL_REGS, so
- we give them the highest cost. */
- if (from != SPECIAL_REGS && from != MOF_REGS
- && from != GENERAL_REGS && from != GENNONACR_REGS)
- from = ALL_REGS;
-
- if (to != SPECIAL_REGS && to != MOF_REGS
- && to != GENERAL_REGS && to != GENNONACR_REGS)
- to = ALL_REGS;
- }
-
/* Can't move to and from a SPECIAL_REGS register, so we have to say
their move cost within that class is higher. How about 7? That's 3
for a move to a GENERAL_REGS register, 3 for the move from the
GENERAL_REGS register, and 1 for the increased register pressure.
- Also, it's higher than the memory move cost, which is in order.
+ Also, it's higher than the memory move cost, as it should.
We also do this for ALL_REGS, since we don't want that class to be
preferred (even to memory) at all where GENERAL_REGS doesn't fit.
Whenever it's about to be used, it's for SPECIAL_REGS. If we don't
@@ -1386,13 +1373,15 @@ cris_register_move_cost (enum machine_mode mode ATTRIBUTE_UNUSED,
GENERAL_REGS left to allocate. This is because the fall-back when
the most preferred register class isn't available, isn't the next
(or next good) wider register class, but the *most widest* register
- class. */
+ class. FIXME: pre-IRA comment, perhaps obsolete now. */
if ((reg_classes_intersect_p (from, SPECIAL_REGS)
&& reg_classes_intersect_p (to, SPECIAL_REGS))
|| from == ALL_REGS || to == ALL_REGS)
return 7;
+ /* Make moves to/from SPECIAL_REGS slightly more expensive, as we
+ generally prefer GENERAL_REGS. */
if (reg_classes_intersect_p (from, SPECIAL_REGS)
|| reg_classes_intersect_p (to, SPECIAL_REGS))
return 3;
diff --git gcc/config/cris/cris.h gcc/config/cris/cris.h
index 57bdd46..872165e 100644
--- gcc/config/cris/cris.h
+++ gcc/config/cris/cris.h
@@ -418,7 +418,7 @@ extern int cris_cpu_version;
registers are fixed at the moment. The faked argument pointer register
is fixed too. */
#define FIXED_REGISTERS \
- {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 0}
+ {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1}
/* Register r9 is used for structure-address, r10-r13 for parameters,
r10- for return values. */
@@ -488,17 +488,17 @@ extern int cris_cpu_version;
/* Node: Register Classes */
-/* FIXME: A separate class for the return register would make sense.
-
- We need a separate register class to handle register allocation for
+/* We need a separate register class to handle register allocation for
ACR, since it can't be used for post-increment.
It's not obvious, but having subunions of all movable-between
- register classes does really help register allocation. */
+ register classes does really help register allocation (pre-IRA
+ comment). */
enum reg_class
{
NO_REGS,
- ACR_REGS, MOF_REGS, CC0_REGS, SPECIAL_REGS,
+ ACR_REGS, MOF_REGS, SRP_REGS, CC0_REGS,
+ MOF_SRP_REGS, SPECIAL_REGS,
SPEC_ACR_REGS, GENNONACR_REGS,
SPEC_GENNONACR_REGS, GENERAL_REGS,
ALL_REGS,
@@ -509,7 +509,8 @@ enum reg_class
#define REG_CLASS_NAMES \
{"NO_REGS", \
- "ACR_REGS", "MOF_REGS", "CC0_REGS", "SPECIAL_REGS", \
+ "ACR_REGS", "MOF_REGS", "SRP_REGS", "CC0_REGS", \
+ "MOF_SRP_REGS", "SPECIAL_REGS", \
"SPEC_ACR_REGS", "GENNONACR_REGS", "SPEC_GENNONACR_REGS", \
"GENERAL_REGS", "ALL_REGS"}
@@ -522,7 +523,10 @@ enum reg_class
{0}, \
{1 << CRIS_ACR_REGNUM}, \
{1 << CRIS_MOF_REGNUM}, \
+ {1 << CRIS_SRP_REGNUM}, \
{1 << CRIS_CC0_REGNUM}, \
+ {(1 << CRIS_MOF_REGNUM) \
+ | (1 << CRIS_SRP_REGNUM)}, \
{CRIS_SPECIAL_REGS_CONTENTS}, \
{CRIS_SPECIAL_REGS_CONTENTS \
| (1 << CRIS_ACR_REGNUM)}, \
@@ -539,8 +543,8 @@ enum reg_class
#define REGNO_REG_CLASS(REGNO) \
((REGNO) == CRIS_ACR_REGNUM ? ACR_REGS : \
(REGNO) == CRIS_MOF_REGNUM ? MOF_REGS : \
+ (REGNO) == CRIS_SRP_REGNUM ? SRP_REGS : \
(REGNO) == CRIS_CC0_REGNUM ? CC0_REGS : \
- (REGNO) == CRIS_SRP_REGNUM ? SPECIAL_REGS : \
GENERAL_REGS)
#define BASE_REG_CLASS GENERAL_REGS
@@ -590,6 +594,7 @@ enum reg_class
#define PREFERRED_RELOAD_CLASS(X, CLASS) \
((CLASS) != ACR_REGS \
&& (CLASS) != MOF_REGS \
+ && (CLASS) != SRP_REGS \
&& (CLASS) != CC0_REGS \
&& (CLASS) != SPECIAL_REGS \
? GENERAL_REGS : (CLASS))
@@ -601,7 +606,7 @@ enum reg_class
the effect that any X that isn't a special-register is treated as
a non-empty intersection with GENERAL_REGS. */
#define SECONDARY_RELOAD_CLASS(CLASS, MODE, X) \
- ((((CLASS) == SPECIAL_REGS || (CLASS) == MOF_REGS) \
+ ((reg_class_subset_p (CLASS, SPECIAL_REGS) \
&& ((GET_MODE_SIZE (MODE) < 4 && MEM_P (X)) \
|| !reg_classes_intersect_p (REGNO_REG_CLASS (true_regnum (X)), \
GENERAL_REGS))) \
brgds, H-P