[PATCH v2 1/2] libatomic: atomic_16.S: Improve ENTRY, END and ALIAS macro interface

[Victor Do Nascimento <victor.donascimento@arm.com>]

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)', we would now have
`MACRO(name, feature)' and in the macro definition body we replace
`name` with `name##feature`.

libatomic/ChangeLog:
	* config/linux/aarch64/atomic_16.S (CORE): New macro.
	(LSE2): Likewise.
	(ENTRY): Modify macro to take in `arch' argument.
	(END): Likewise.
	(ALIAS): Likewise.
	(ENTRY1): New macro.
	(END1): Likewise.
	(ALIAS): Likewise.
---
 libatomic/config/linux/aarch64/atomic_16.S | 147 +++++++++++----------
 1 file changed, 79 insertions(+), 68 deletions(-)

diff --git a/libatomic/config/linux/aarch64/atomic_16.S b/libatomic/config/linux/aarch64/atomic_16.S
index 0485c284117..3f6225830e6 100644
--- a/libatomic/config/linux/aarch64/atomic_16.S
+++ b/libatomic/config/linux/aarch64/atomic_16.S
@@ -39,22 +39,34 @@
 
 	.arch	armv8-a+lse
 
-#define ENTRY(name)		\
-	.global name;		\
-	.hidden name;		\
-	.type name,%function;	\
-	.p2align 4;		\
-name:				\
-	.cfi_startproc;		\
+#define ENTRY(name, feat)		\
+	ENTRY1(name, feat)
+
+#define ENTRY1(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, feat)			\
+	END1(name, feat)
 
-#define ALIAS(alias,name)	\
-	.global alias;		\
-	.set alias, name;
+#define END1(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
@@ -89,7 +101,7 @@ name:				\
 #define SEQ_CST 5
 
 
-ENTRY (libat_load_16)
+ENTRY (libat_load_16, CORE)
 	mov	x5, x0
 	cbnz	w1, 2f
 
@@ -104,10 +116,10 @@ ENTRY (libat_load_16)
 	stxp	w4, res0, res1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_load_16)
+END (libat_load_16, CORE)
 
 
-ENTRY (libat_load_16_i1)
+ENTRY (libat_load_16, LSE2)
 	cbnz	w1, 1f
 
 	/* RELAXED.  */
@@ -127,10 +139,10 @@ ENTRY (libat_load_16_i1)
 	ldp	res0, res1, [x0]
 	dmb	ishld
 	ret
-END (libat_load_16_i1)
+END (libat_load_16, LSE2)
 
 
-ENTRY (libat_store_16)
+ENTRY (libat_store_16, CORE)
 	cbnz	w4, 2f
 
 	/* RELAXED.  */
@@ -144,10 +156,10 @@ ENTRY (libat_store_16)
 	stlxp	w4, in0, in1, [x0]
 	cbnz	w4, 2b
 	ret
-END (libat_store_16)
+END (libat_store_16, CORE)
 
 
-ENTRY (libat_store_16_i1)
+ENTRY (libat_store_16, LSE2)
 	cbnz	w4, 1f
 
 	/* RELAXED.  */
@@ -159,10 +171,10 @@ ENTRY (libat_store_16_i1)
 	stlxp	w4, in0, in1, [x0]
 	cbnz	w4, 1b
 	ret
-END (libat_store_16_i1)
+END (libat_store_16, LSE2)
 
 
-ENTRY (libat_exchange_16)
+ENTRY (libat_exchange_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -186,10 +198,10 @@ ENTRY (libat_exchange_16)
 	stlxp	w4, in0, in1, [x5]
 	cbnz	w4, 4b
 	ret
-END (libat_exchange_16)
+END (libat_exchange_16, CORE)
 
 
-ENTRY (libat_compare_exchange_16)
+ENTRY (libat_compare_exchange_16, CORE)
 	ldp	exp0, exp1, [x1]
 	cbz	w4, 3f
 	cmp	w4, RELEASE
@@ -228,10 +240,10 @@ ENTRY (libat_compare_exchange_16)
 	cbnz	w4, 4b
 	mov	x0, 1
 	ret
-END (libat_compare_exchange_16)
+END (libat_compare_exchange_16, CORE)
 
 
-ENTRY (libat_compare_exchange_16_i1)
+ENTRY (libat_compare_exchange_16, LSE2)
 	ldp	exp0, exp1, [x1]
 	mov	tmp0, exp0
 	mov	tmp1, exp1
@@ -264,10 +276,10 @@ 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 (libat_compare_exchange_16, LSE2)
 
 
-ENTRY (libat_fetch_add_16)
+ENTRY (libat_fetch_add_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -286,10 +298,10 @@ ENTRY (libat_fetch_add_16)
 	stlxp	w4, tmp0, tmp1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_fetch_add_16)
+END (libat_fetch_add_16, CORE)
 
 
-ENTRY (libat_add_fetch_16)
+ENTRY (libat_add_fetch_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -308,10 +320,10 @@ ENTRY (libat_add_fetch_16)
 	stlxp	w4, res0, res1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_add_fetch_16)
+END (libat_add_fetch_16, CORE)
 
 
-ENTRY (libat_fetch_sub_16)
+ENTRY (libat_fetch_sub_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -330,10 +342,10 @@ ENTRY (libat_fetch_sub_16)
 	stlxp	w4, tmp0, tmp1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_fetch_sub_16)
+END (libat_fetch_sub_16, CORE)
 
 
-ENTRY (libat_sub_fetch_16)
+ENTRY (libat_sub_fetch_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -352,10 +364,10 @@ ENTRY (libat_sub_fetch_16)
 	stlxp	w4, res0, res1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_sub_fetch_16)
+END (libat_sub_fetch_16, CORE)
 
 
-ENTRY (libat_fetch_or_16)
+ENTRY (libat_fetch_or_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -374,10 +386,10 @@ ENTRY (libat_fetch_or_16)
 	stlxp	w4, tmp0, tmp1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_fetch_or_16)
+END (libat_fetch_or_16, CORE)
 
 
-ENTRY (libat_or_fetch_16)
+ENTRY (libat_or_fetch_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -396,10 +408,10 @@ ENTRY (libat_or_fetch_16)
 	stlxp	w4, res0, res1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_or_fetch_16)
+END (libat_or_fetch_16, CORE)
 
 
-ENTRY (libat_fetch_and_16)
+ENTRY (libat_fetch_and_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -418,10 +430,10 @@ ENTRY (libat_fetch_and_16)
 	stlxp	w4, tmp0, tmp1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_fetch_and_16)
+END (libat_fetch_and_16, CORE)
 
 
-ENTRY (libat_and_fetch_16)
+ENTRY (libat_and_fetch_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -440,10 +452,10 @@ ENTRY (libat_and_fetch_16)
 	stlxp	w4, res0, res1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_and_fetch_16)
+END (libat_and_fetch_16, CORE)
 
 
-ENTRY (libat_fetch_xor_16)
+ENTRY (libat_fetch_xor_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -462,10 +474,10 @@ ENTRY (libat_fetch_xor_16)
 	stlxp	w4, tmp0, tmp1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_fetch_xor_16)
+END (libat_fetch_xor_16, CORE)
 
 
-ENTRY (libat_xor_fetch_16)
+ENTRY (libat_xor_fetch_16, CORE)
 	mov	x5, x0
 	cbnz	w4, 2f
 
@@ -484,10 +496,10 @@ ENTRY (libat_xor_fetch_16)
 	stlxp	w4, res0, res1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_xor_fetch_16)
+END (libat_xor_fetch_16, CORE)
 
 
-ENTRY (libat_fetch_nand_16)
+ENTRY (libat_fetch_nand_16, CORE)
 	mov	x5, x0
 	mvn	in0, in0
 	mvn	in1, in1
@@ -508,10 +520,10 @@ ENTRY (libat_fetch_nand_16)
 	stlxp	w4, tmp0, tmp1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_fetch_nand_16)
+END (libat_fetch_nand_16, CORE)
 
 
-ENTRY (libat_nand_fetch_16)
+ENTRY (libat_nand_fetch_16, CORE)
 	mov	x5, x0
 	mvn	in0, in0
 	mvn	in1, in1
@@ -532,12 +544,12 @@ ENTRY (libat_nand_fetch_16)
 	stlxp	w4, res0, res1, [x5]
 	cbnz	w4, 2b
 	ret
-END (libat_nand_fetch_16)
+END (libat_nand_fetch_16, CORE)
 
 
 /* __atomic_test_and_set is always inlined, so this entry is unused and
    only required for completeness.  */
-ENTRY (libat_test_and_set_16)
+ENTRY (libat_test_and_set_16, CORE)
 
 	/* RELAXED/ACQUIRE/CONSUME/RELEASE/ACQ_REL/SEQ_CST.  */
 	mov	x5, x0
@@ -545,26 +557,25 @@ ENTRY (libat_test_and_set_16)
 	stlxrb	w4, w2, [x5]
 	cbnz	w4, 1b
 	ret
-END (libat_test_and_set_16)
+END (libat_test_and_set_16, CORE)
 
 
 /* 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