The introduction of further architectural-feature dependent ifuncs
for AArch64 makes hard-coding ifunc `_i<n>' suffixes to functions
cumbersome to work with. It is awkward to remember which ifunc maps
onto which arch feature and makes the code harder to maintain when new
ifuncs are added and their suffixes possibly altered.
This patch uses pre-processor `#define' statements to map each suffix to
a descriptive feature name macro, for example:
#define LSE2 _i1
and reconstructs function names with the pre-processor's token
concatenation feature, such that for `MACRO(<name>_i<n>)', we would
now have `MACRO_FEAT(name, feature)' and in the macro definition body
we replace `name` with `name##feature`.
Consequently, for base functionality, where the ifunc suffix is
absent, the macro interface remains the same. For example, the entry
and endpoints of `libat_store_16' remain defined by:
- ENTRY (libat_store_16)
and
- END (libat_store_16)
For the LSE2 implementation of the same 16-byte atomic store, we now
have:
- ENTRY_FEAT (libat_store_16, LSE2)
and
- END_FEAT (libat_store_16, LSE2)
For the alising of ifunc names, we define the following new
implementation of the ALIAS macro:
- ALIAS (FN_BASE_NAME, FROM_SUFFIX, TO_SUFFIX)
Defining the base feature name macro to map `CORE' to the empty string,
mapping LSE2 to the base implementation, we'd alias the LSE2
`libat_exchange_16' to it base implementation with:
- ALIAS (libat_exchange_16, LSE2, CORE)
libatomic/ChangeLog:
* config/linux/aarch64/atomic_16.S (CORE): New macro.
(LSE2): Likewise.
(ENTRY_FEAT): Likewise.
(END_FEAT): Likewise.
(ENTRY_FEAT1): Likewise.
(END_FEAT1): Likewise.
(ALIAS): Modify macro to take in `arch' arguments.
---
libatomic/config/linux/aarch64/atomic_16.S | 83 +++++++++++++---------
1 file changed, 49 insertions(+), 34 deletions(-)
diff --git a/libatomic/config/linux/aarch64/atomic_16.S
b/libatomic/config/linux/aarch64/atomic_16.S
index a099037179b..eb8e749b8a2 100644
--- a/libatomic/config/linux/aarch64/atomic_16.S
+++ b/libatomic/config/linux/aarch64/atomic_16.S
@@ -40,22 +40,38 @@
.arch armv8-a+lse
-#define ENTRY(name) \
- .global name; \
- .hidden name; \
- .type name,%function; \
- .p2align 4; \
-name: \
- .cfi_startproc; \
+#define ENTRY(name) ENTRY_FEAT (name, CORE)
+
+#define ENTRY_FEAT(name, feat) \
+ ENTRY_FEAT1(name, feat)
+
+#define ENTRY_FEAT1(name, feat) \
+ .global name##feat; \
+ .hidden name##feat; \
+ .type name##feat,%function; \
+ .p2align 4; \
+name##feat: \
+ .cfi_startproc; \
hint 34 // bti c
-#define END(name) \
- .cfi_endproc; \
- .size name, .-name;
+#define END(name) END_FEAT (name, CORE)
-#define ALIAS(alias,name) \
- .global alias; \
- .set alias, name;
+#define END_FEAT(name, feat) \
+ END_FEAT1(name, feat)
+
+#define END_FEAT1(name, feat) \
+ .cfi_endproc; \
+ .size name##feat, .-name##feat;
+
+#define ALIAS(alias, from, to) \
+ ALIAS1(alias,from,to)
+
+#define ALIAS1(alias, from, to) \
+ .global alias##from; \
+ .set alias##from, alias##to;
+
+#define CORE
+#define LSE2 _i1
#define res0 x0
#define res1 x1
@@ -108,7 +124,7 @@ ENTRY (libat_load_16)
END (libat_load_16)
-ENTRY (libat_load_16_i1)
+ENTRY_FEAT (libat_load_16, LSE2)
cbnz w1, 1f
/* RELAXED. */
@@ -128,7 +144,7 @@ ENTRY (libat_load_16_i1)
ldp res0, res1, [x0]
dmb ishld
ret
-END (libat_load_16_i1)
+END_FEAT (libat_load_16, LSE2)
ENTRY (libat_store_16)
@@ -148,7 +164,7 @@ ENTRY (libat_store_16)
END (libat_store_16)
-ENTRY (libat_store_16_i1)
+ENTRY_FEAT (libat_store_16, LSE2)
cbnz w4, 1f
/* RELAXED. */
@@ -160,7 +176,7 @@ ENTRY (libat_store_16_i1)
stlxp w4, in0, in1, [x0]
cbnz w4, 1b
ret
-END (libat_store_16_i1)
+END_FEAT (libat_store_16, LSE2)
ENTRY (libat_exchange_16)
@@ -237,7 +253,7 @@ ENTRY (libat_compare_exchange_16)
END (libat_compare_exchange_16)
-ENTRY (libat_compare_exchange_16_i1)
+ENTRY_FEAT (libat_compare_exchange_16, LSE2)
ldp exp0, exp1, [x1]
mov tmp0, exp0
mov tmp1, exp1
@@ -270,7 +286,7 @@ ENTRY (libat_compare_exchange_16_i1)
/* ACQ_REL/SEQ_CST. */
4: caspal exp0, exp1, in0, in1, [x0]
b 0b
-END (libat_compare_exchange_16_i1)
+END_FEAT (libat_compare_exchange_16, LSE2)
ENTRY (libat_fetch_add_16)
@@ -556,21 +572,20 @@ END (libat_test_and_set_16)
/* Alias entry points which are the same in baseline and LSE2. */
-ALIAS (libat_exchange_16_i1, libat_exchange_16)
-ALIAS (libat_fetch_add_16_i1, libat_fetch_add_16)
-ALIAS (libat_add_fetch_16_i1, libat_add_fetch_16)
-ALIAS (libat_fetch_sub_16_i1, libat_fetch_sub_16)
-ALIAS (libat_sub_fetch_16_i1, libat_sub_fetch_16)
-ALIAS (libat_fetch_or_16_i1, libat_fetch_or_16)
-ALIAS (libat_or_fetch_16_i1, libat_or_fetch_16)
-ALIAS (libat_fetch_and_16_i1, libat_fetch_and_16)
-ALIAS (libat_and_fetch_16_i1, libat_and_fetch_16)
-ALIAS (libat_fetch_xor_16_i1, libat_fetch_xor_16)
-ALIAS (libat_xor_fetch_16_i1, libat_xor_fetch_16)
-ALIAS (libat_fetch_nand_16_i1, libat_fetch_nand_16)
-ALIAS (libat_nand_fetch_16_i1, libat_nand_fetch_16)
-ALIAS (libat_test_and_set_16_i1, libat_test_and_set_16)
-
+ALIAS (libat_exchange_16, LSE2, CORE)
+ALIAS (libat_fetch_add_16, LSE2, CORE)
+ALIAS (libat_add_fetch_16, LSE2, CORE)
+ALIAS (libat_fetch_sub_16, LSE2, CORE)
+ALIAS (libat_sub_fetch_16, LSE2, CORE)
+ALIAS (libat_fetch_or_16, LSE2, CORE)
+ALIAS (libat_or_fetch_16, LSE2, CORE)
+ALIAS (libat_fetch_and_16, LSE2, CORE)
+ALIAS (libat_and_fetch_16, LSE2, CORE)
+ALIAS (libat_fetch_xor_16, LSE2, CORE)
+ALIAS (libat_xor_fetch_16, LSE2, CORE)
+ALIAS (libat_fetch_nand_16, LSE2, CORE)
+ALIAS (libat_nand_fetch_16, LSE2, CORE)
+ALIAS (libat_test_and_set_16, LSE2, CORE)
/* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code. */
#define FEATURE_1_AND 0xc0000000
--
2.42.0
