libatomic: Cleanup macros in atomic_16.S

  As mentioned in https://gcc.gnu.org/pipermail/gcc-patches/2024-March/648397.html ,
do some additional cleanup of the macros and aliases:

Cleanup the macros to add the libat_ prefixes in atomic_16.S.  Emit the
alias to __atomic_<op> when ifuncs are not enabled in the ENTRY macro.

Passes regress and bootstrap, OK for commit?

libatomic:
        * config/linux/aarch64/atomic_16.S: Add __libat_ prefix in the
        LSE2/LSE128/CORE macros, remove elsewhere.  Add ATOMIC macro.

---
  

Wilco Dijkstra <Wilco.Dijkstra@arm.com> writes:
> As mentioned in https://gcc.gnu.org/pipermail/gcc-patches/2024-March/648397.html ,
> do some additional cleanup of the macros and aliases:
>
> Cleanup the macros to add the libat_ prefixes in atomic_16.S.  Emit the
> alias to __atomic_<op> when ifuncs are not enabled in the ENTRY macro.
>
> Passes regress and bootstrap, OK for commit?
>
> libatomic:
>         * config/linux/aarch64/atomic_16.S: Add __libat_ prefix in the
>         LSE2/LSE128/CORE macros, remove elsewhere.  Add ATOMIC macro.

Thanks for doing this.  LGTM, but one minor suggestion below:

> diff --git a/libatomic/config/linux/aarch64/atomic_16.S b/libatomic/config/linux/aarch64/atomic_16.S
> index 4e3fa870b0338da4cfcdb0879ab8bed8d041a0a3..d0343507120c06a483ffdae1a793b6b5263cfe98 100644
> --- a/libatomic/config/linux/aarch64/atomic_16.S
> +++ b/libatomic/config/linux/aarch64/atomic_16.S
> @@ -45,7 +45,7 @@
>  # define HAVE_FEAT_LSE128 0
>  #endif
>
> -#define HAVE_FEAT_LSE2  HAVE_IFUNC
> +#define HAVE_FEAT_LSE2 HAVE_IFUNC
>
>  #if HAVE_FEAT_LSE128
>         .arch   armv9-a+lse128
> @@ -53,31 +53,37 @@
>         .arch   armv8-a+lse
>  #endif
>
> -#define LSE128(NAME)   NAME##_i1
> -#define LSE2(NAME)     NAME##_i2
> -#define CORE(NAME)     NAME
> +#define LSE128(NAME)   libat_##NAME##_i1
> +#define LSE2(NAME)     libat_##NAME##_i2
> +#define CORE(NAME)     libat_##NAME
> +#define ATOMIC(NAME)   __atomic_##NAME
>
> -#define ENTRY_FEAT(NAME, FEAT)  \
> -       ENTRY (FEAT (NAME))
> +#if HAVE_IFUNC
> +# define ENTRY(NAME)   ENTRY2 (CORE (NAME), )
> +#else
> +/* Emit __atomic_* entrypoints if no ifuncs.  */
> +# define ENTRY(NAME)   ENTRY2 (CORE (NAME), ALIAS (NAME, ATOMIC, CORE))
> +#endif
> +#define ENTRY_FEAT(NAME, FEAT) ENTRY2 (FEAT (NAME), )

Perhaps we should define this only in the HAVE_IFUNC arm, so that it's
a noisy failure if we forget to protect an ENTRY_FEAT with an appropriate
#ifdef.

OK for GCC 15 with or without that change.

Richard

> +
> +#define END(NAME)              END2 (CORE (NAME))
> +#define END_FEAT(NAME, FEAT)   END2 (FEAT (NAME))
>
> -#define ENTRY(NAME)            \
> +#define ENTRY2(NAME, ALIASES)  \
>         .global NAME;           \
>         .hidden NAME;           \
>         .type NAME,%function;   \
>         .p2align 4;             \
> +       ALIASES;                \
>  NAME:                          \
> -       .cfi_startproc; \
> -       hint    34      // bti c
> -
> -#define END_FEAT(NAME, FEAT)   \
> -       END (FEAT (NAME))
> +       .cfi_startproc;         \
> +       hint    34;     // bti c
>
> -#define END(NAME)              \
> +#define END2(NAME)             \
>         .cfi_endproc;           \
>         .size NAME, .-NAME;
>
> -#define ALIAS(NAME, FROM, TO)  ALIAS1 (FROM (NAME),TO (NAME))
> -#define ALIAS2(NAME)           ALIAS1 (__atomic_##NAME, libat_##NAME)
> +#define ALIAS(NAME, FROM, TO)  ALIAS1 (FROM (NAME), TO (NAME))
>
>  #define ALIAS1(ALIAS, NAME)    \
>         .global ALIAS;          \
> @@ -116,7 +122,7 @@ NAME:                               \
>  #define SEQ_CST 5
>
>
> -ENTRY (libat_load_16)
> +ENTRY (load_16)
>         mov     x5, x0
>         cbnz    w1, 2f
>
> @@ -131,11 +137,11 @@ ENTRY (libat_load_16)
>         stxp    w4, res0, res1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_load_16)
> +END (load_16)
>
>
>  #if HAVE_FEAT_LSE2
> -ENTRY_FEAT (libat_load_16, LSE2)
> +ENTRY_FEAT (load_16, LSE2)
>         cbnz    w1, 1f
>
>         /* RELAXED.  */
> @@ -155,11 +161,11 @@ ENTRY_FEAT (libat_load_16, LSE2)
>         ldp     res0, res1, [x0]
>         dmb     ishld
>         ret
> -END_FEAT (libat_load_16, LSE2)
> +END_FEAT (load_16, LSE2)
>  #endif
>
>
> -ENTRY (libat_store_16)
> +ENTRY (store_16)
>         cbnz    w4, 2f
>
>         /* RELAXED.  */
> @@ -173,11 +179,11 @@ ENTRY (libat_store_16)
>         stlxp   w4, in0, in1, [x0]
>         cbnz    w4, 2b
>         ret
> -END (libat_store_16)
> +END (store_16)
>
>
>  #if HAVE_FEAT_LSE2
> -ENTRY_FEAT (libat_store_16, LSE2)
> +ENTRY_FEAT (store_16, LSE2)
>         cbnz    w4, 1f
>
>         /* RELAXED.  */
> @@ -189,11 +195,11 @@ ENTRY_FEAT (libat_store_16, LSE2)
>         stlxp   w4, in0, in1, [x0]
>         cbnz    w4, 1b
>         ret
> -END_FEAT (libat_store_16, LSE2)
> +END_FEAT (store_16, LSE2)
>  #endif
>
>
> -ENTRY (libat_exchange_16)
> +ENTRY (exchange_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -217,11 +223,11 @@ ENTRY (libat_exchange_16)
>         stlxp   w4, in0, in1, [x5]
>         cbnz    w4, 4b
>         ret
> -END (libat_exchange_16)
> +END (exchange_16)
>
>
>  #if HAVE_FEAT_LSE128
> -ENTRY_FEAT (libat_exchange_16, LSE128)
> +ENTRY_FEAT (exchange_16, LSE128)
>         mov     tmp0, x0
>         mov     res0, in0
>         mov     res1, in1
> @@ -241,11 +247,11 @@ ENTRY_FEAT (libat_exchange_16, LSE128)
>         /* RELEASE/ACQ_REL/SEQ_CST.  */
>  2:     swppal  res0, res1, [tmp0]
>         ret
> -END_FEAT (libat_exchange_16, LSE128)
> +END_FEAT (exchange_16, LSE128)
>  #endif
>
>
> -ENTRY (libat_compare_exchange_16)
> +ENTRY (compare_exchange_16)
>         ldp     exp0, exp1, [x1]
>         cbz     w4, 3f
>         cmp     w4, RELEASE
> @@ -289,11 +295,11 @@ ENTRY (libat_compare_exchange_16)
>         stp     tmp0, tmp1, [x1]
>  6:     cset    x0, eq
>         ret
> -END (libat_compare_exchange_16)
> +END (compare_exchange_16)
>
>
>  #if HAVE_FEAT_LSE2
> -ENTRY_FEAT (libat_compare_exchange_16, LSE2)
> +ENTRY_FEAT (compare_exchange_16, LSE2)
>         ldp     exp0, exp1, [x1]
>         mov     tmp0, exp0
>         mov     tmp1, exp1
> @@ -326,11 +332,11 @@ ENTRY_FEAT (libat_compare_exchange_16, LSE2)
>         /* ACQ_REL/SEQ_CST.  */
>  4:     caspal  exp0, exp1, in0, in1, [x0]
>         b       0b
> -END_FEAT (libat_compare_exchange_16, LSE2)
> +END_FEAT (compare_exchange_16, LSE2)
>  #endif
>
>
> -ENTRY (libat_fetch_add_16)
> +ENTRY (fetch_add_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -349,10 +355,10 @@ ENTRY (libat_fetch_add_16)
>         stlxp   w4, tmp0, tmp1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_fetch_add_16)
> +END (fetch_add_16)
>
>
> -ENTRY (libat_add_fetch_16)
> +ENTRY (add_fetch_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -371,10 +377,10 @@ ENTRY (libat_add_fetch_16)
>         stlxp   w4, res0, res1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_add_fetch_16)
> +END (add_fetch_16)
>
>
> -ENTRY (libat_fetch_sub_16)
> +ENTRY (fetch_sub_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -393,10 +399,10 @@ ENTRY (libat_fetch_sub_16)
>         stlxp   w4, tmp0, tmp1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_fetch_sub_16)
> +END (fetch_sub_16)
>
>
> -ENTRY (libat_sub_fetch_16)
> +ENTRY (sub_fetch_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -415,10 +421,10 @@ ENTRY (libat_sub_fetch_16)
>         stlxp   w4, res0, res1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_sub_fetch_16)
> +END (sub_fetch_16)
>
>
> -ENTRY (libat_fetch_or_16)
> +ENTRY (fetch_or_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -437,11 +443,11 @@ ENTRY (libat_fetch_or_16)
>         stlxp   w4, tmp0, tmp1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_fetch_or_16)
> +END (fetch_or_16)
>
>
>  #if HAVE_FEAT_LSE128
> -ENTRY_FEAT (libat_fetch_or_16, LSE128)
> +ENTRY_FEAT (fetch_or_16, LSE128)
>         mov     tmp0, x0
>         mov     res0, in0
>         mov     res1, in1
> @@ -461,11 +467,11 @@ ENTRY_FEAT (libat_fetch_or_16, LSE128)
>         /* RELEASE/ACQ_REL/SEQ_CST.  */
>  2:     ldsetpal        res0, res1, [tmp0]
>         ret
> -END_FEAT (libat_fetch_or_16, LSE128)
> +END_FEAT (fetch_or_16, LSE128)
>  #endif
>
>
> -ENTRY (libat_or_fetch_16)
> +ENTRY (or_fetch_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -484,11 +490,11 @@ ENTRY (libat_or_fetch_16)
>         stlxp   w4, res0, res1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_or_fetch_16)
> +END (or_fetch_16)
>
>
>  #if HAVE_FEAT_LSE128
> -ENTRY_FEAT (libat_or_fetch_16, LSE128)
> +ENTRY_FEAT (or_fetch_16, LSE128)
>         cbnz    w4, 1f
>         mov     tmp0, in0
>         mov     tmp1, in1
> @@ -513,11 +519,11 @@ ENTRY_FEAT (libat_or_fetch_16, LSE128)
>         orr     res0, in0, tmp0
>         orr     res1, in1, tmp1
>         ret
> -END_FEAT (libat_or_fetch_16, LSE128)
> +END_FEAT (or_fetch_16, LSE128)
>  #endif
>
>
> -ENTRY (libat_fetch_and_16)
> +ENTRY (fetch_and_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -536,11 +542,11 @@ ENTRY (libat_fetch_and_16)
>         stlxp   w4, tmp0, tmp1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_fetch_and_16)
> +END (fetch_and_16)
>
>
>  #if HAVE_FEAT_LSE128
> -ENTRY_FEAT (libat_fetch_and_16, LSE128)
> +ENTRY_FEAT (fetch_and_16, LSE128)
>         mov     tmp0, x0
>         mvn     res0, in0
>         mvn     res1, in1
> @@ -561,11 +567,11 @@ ENTRY_FEAT (libat_fetch_and_16, LSE128)
>         /* RELEASE/ACQ_REL/SEQ_CST.  */
>  2:     ldclrpal        res0, res1, [tmp0]
>         ret
> -END_FEAT (libat_fetch_and_16, LSE128)
> +END_FEAT (fetch_and_16, LSE128)
>  #endif
>
>
> -ENTRY (libat_and_fetch_16)
> +ENTRY (and_fetch_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -584,11 +590,11 @@ ENTRY (libat_and_fetch_16)
>         stlxp   w4, res0, res1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_and_fetch_16)
> +END (and_fetch_16)
>
>
>  #if HAVE_FEAT_LSE128
> -ENTRY_FEAT (libat_and_fetch_16, LSE128)
> +ENTRY_FEAT (and_fetch_16, LSE128)
>         mvn     tmp0, in0
>         mvn     tmp0, in1
>         cbnz    w4, 1f
> @@ -614,11 +620,11 @@ ENTRY_FEAT (libat_and_fetch_16, LSE128)
>         and     res0, tmp0, in0
>         and     res1, tmp1, in1
>         ret
> -END_FEAT (libat_and_fetch_16, LSE128)
> +END_FEAT (and_fetch_16, LSE128)
>  #endif
>
>
> -ENTRY (libat_fetch_xor_16)
> +ENTRY (fetch_xor_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -637,10 +643,10 @@ ENTRY (libat_fetch_xor_16)
>         stlxp   w4, tmp0, tmp1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_fetch_xor_16)
> +END (fetch_xor_16)
>
>
> -ENTRY (libat_xor_fetch_16)
> +ENTRY (xor_fetch_16)
>         mov     x5, x0
>         cbnz    w4, 2f
>
> @@ -659,10 +665,10 @@ ENTRY (libat_xor_fetch_16)
>         stlxp   w4, res0, res1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_xor_fetch_16)
> +END (xor_fetch_16)
>
>
> -ENTRY (libat_fetch_nand_16)
> +ENTRY (fetch_nand_16)
>         mov     x5, x0
>         mvn     in0, in0
>         mvn     in1, in1
> @@ -683,10 +689,10 @@ ENTRY (libat_fetch_nand_16)
>         stlxp   w4, tmp0, tmp1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_fetch_nand_16)
> +END (fetch_nand_16)
>
>
> -ENTRY (libat_nand_fetch_16)
> +ENTRY (nand_fetch_16)
>         mov     x5, x0
>         mvn     in0, in0
>         mvn     in1, in1
> @@ -707,12 +713,12 @@ ENTRY (libat_nand_fetch_16)
>         stlxp   w4, res0, res1, [x5]
>         cbnz    w4, 2b
>         ret
> -END (libat_nand_fetch_16)
> +END (nand_fetch_16)
>
>
>  /* __atomic_test_and_set is always inlined, so this entry is unused and
>     only required for completeness.  */
> -ENTRY (libat_test_and_set_16)
> +ENTRY (test_and_set_16)
>
>         /* RELAXED/ACQUIRE/CONSUME/RELEASE/ACQ_REL/SEQ_CST.  */
>         mov     x5, x0
> @@ -720,70 +726,48 @@ ENTRY (libat_test_and_set_16)
>         stlxrb  w4, w2, [x5]
>         cbnz    w4, 1b
>         ret
> -END (libat_test_and_set_16)
> +END (test_and_set_16)
>
>
>  /* Alias entry points which are the same in LSE2 and LSE128.  */
>
>  #if HAVE_IFUNC
>  # if !HAVE_FEAT_LSE128
> -ALIAS (libat_exchange_16, LSE128, LSE2)
> -ALIAS (libat_fetch_or_16, LSE128, LSE2)
> -ALIAS (libat_fetch_and_16, LSE128, LSE2)
> -ALIAS (libat_or_fetch_16, LSE128, LSE2)
> -ALIAS (libat_and_fetch_16, LSE128, LSE2)
> +ALIAS (exchange_16, LSE128, LSE2)
> +ALIAS (fetch_or_16, LSE128, LSE2)
> +ALIAS (fetch_and_16, LSE128, LSE2)
> +ALIAS (or_fetch_16, LSE128, LSE2)
> +ALIAS (and_fetch_16, LSE128, LSE2)
>  # endif
> -ALIAS (libat_load_16, LSE128, LSE2)
> -ALIAS (libat_store_16, LSE128, LSE2)
> -ALIAS (libat_compare_exchange_16, LSE128, LSE2)
> -ALIAS (libat_fetch_add_16, LSE128, LSE2)
> -ALIAS (libat_add_fetch_16, LSE128, LSE2)
> -ALIAS (libat_fetch_sub_16, LSE128, LSE2)
> -ALIAS (libat_sub_fetch_16, LSE128, LSE2)
> -ALIAS (libat_fetch_xor_16, LSE128, LSE2)
> -ALIAS (libat_xor_fetch_16, LSE128, LSE2)
> -ALIAS (libat_fetch_nand_16, LSE128, LSE2)
> -ALIAS (libat_nand_fetch_16, LSE128, LSE2)
> -ALIAS (libat_test_and_set_16, LSE128, LSE2)
> +ALIAS (load_16, LSE128, LSE2)
> +ALIAS (store_16, LSE128, LSE2)
> +ALIAS (compare_exchange_16, LSE128, LSE2)
> +ALIAS (fetch_add_16, LSE128, LSE2)
> +ALIAS (add_fetch_16, LSE128, LSE2)
> +ALIAS (fetch_sub_16, LSE128, LSE2)
> +ALIAS (sub_fetch_16, LSE128, LSE2)
> +ALIAS (fetch_xor_16, LSE128, LSE2)
> +ALIAS (xor_fetch_16, LSE128, LSE2)
> +ALIAS (fetch_nand_16, LSE128, LSE2)
> +ALIAS (nand_fetch_16, LSE128, LSE2)
> +ALIAS (test_and_set_16, LSE128, LSE2)
>
>  /* Alias entry points which are the same in baseline and LSE2.  */
>
> -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)
> -
> -#else
> -
> -/* Emit __atomic_* entrypoints if no ifuncs.  */
> -
> -ALIAS2 (load_16)
> -ALIAS2 (store_16)
> -ALIAS2 (compare_exchange_16)
> -ALIAS2 (exchange_16)
> -ALIAS2 (fetch_add_16)
> -ALIAS2 (add_fetch_16)
> -ALIAS2 (fetch_sub_16)
> -ALIAS2 (sub_fetch_16)
> -ALIAS2 (fetch_or_16)
> -ALIAS2 (or_fetch_16)
> -ALIAS2 (fetch_and_16)
> -ALIAS2 (and_fetch_16)
> -ALIAS2 (fetch_xor_16)
> -ALIAS2 (xor_fetch_16)
> -ALIAS2 (fetch_nand_16)
> -ALIAS2 (nand_fetch_16)
> -ALIAS2 (test_and_set_16)
> +ALIAS (exchange_16, LSE2, CORE)
> +ALIAS (fetch_add_16, LSE2, CORE)
> +ALIAS (add_fetch_16, LSE2, CORE)
> +ALIAS (fetch_sub_16, LSE2, CORE)
> +ALIAS (sub_fetch_16, LSE2, CORE)
> +ALIAS (fetch_or_16, LSE2, CORE)
> +ALIAS (or_fetch_16, LSE2, CORE)
> +ALIAS (fetch_and_16, LSE2, CORE)
> +ALIAS (and_fetch_16, LSE2, CORE)
> +ALIAS (fetch_xor_16, LSE2, CORE)
> +ALIAS (xor_fetch_16, LSE2, CORE)
> +ALIAS (fetch_nand_16, LSE2, CORE)
> +ALIAS (nand_fetch_16, LSE2, CORE)
> +ALIAS (test_and_set_16, LSE2, CORE)
>  #endif
>
>  /* GNU_PROPERTY_AARCH64_* macros from elf.h for use in asm code.  */