[v2] LoongArch: Add built-in functions description of LoongArch Base instruction set instructions.

  gcc/ChangeLog:

	* doc/extend.texi: Add section for LoongArch Base Built-in functions.
---
 gcc/doc/extend.texi | 129 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 129 insertions(+)

---
 v1 -> v2:
   (1) Does not use i8, u8, i16, u16 etc.
   (2) Add the description information of the built-in functions before encapsulation.
  

Pushed to r14-14.

在 2023/4/7 下午4:38, Lulu Cheng 写道:
> gcc/ChangeLog:
>
> 	* doc/extend.texi: Add section for LoongArch Base Built-in functions.
> ---
>   gcc/doc/extend.texi | 129 ++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 129 insertions(+)
>
> ---
>   v1 -> v2:
>     (1) Does not use i8, u8, i16, u16 etc.
>     (2) Add the description information of the built-in functions before encapsulation.
>
> diff --git a/gcc/doc/extend.texi b/gcc/doc/extend.texi
> index 3adb67aa47a..9fbb33b370b 100644
> --- a/gcc/doc/extend.texi
> +++ b/gcc/doc/extend.texi
> @@ -14669,6 +14669,7 @@ instructions, but allow the compiler to schedule those calls.
>   * Blackfin Built-in Functions::
>   * BPF Built-in Functions::
>   * FR-V Built-in Functions::
> +* LoongArch Base Built-in Functions::
>   * MIPS DSP Built-in Functions::
>   * MIPS Paired-Single Support::
>   * MIPS Loongson Built-in Functions::
> @@ -16197,6 +16198,134 @@ Use the @code{nldub} instruction to load the contents of address @var{x}
>   into the data cache.  The instruction is issued in slot I1@.
>   @end table
>
> +@node LoongArch Base Built-in Functions
> +@subsection LoongArch Base Built-in Functions
> +
> +These built-in functions are available for LoongArch.
> +
> +Data Type Description:
> +@itemize
> +@item @code{imm0_31}, a compile-time constant in range 0 to 31;
> +@item @code{imm0_16383}, a compile-time constant in range 0 to 16383;
> +@item @code{imm0_32767}, a compile-time constant in range 0 to 32767;
> +@item @code{imm_n2048_2047}, a compile-time constant in range -2048 to 2047;
> +@end itemize
> +
> +The intrinsics provided are listed below:
> +@smallexample
> +    unsigned int __builtin_loongarch_movfcsr2gr (imm0_31)
> +    void __builtin_loongarch_movgr2fcsr (imm0_31, unsigned int)
> +    void __builtin_loongarch_cacop_d (imm0_31, unsigned long int, imm_n2048_2047)
> +    unsigned int __builtin_loongarch_cpucfg (unsigned int)
> +    void __builtin_loongarch_asrtle_d (long int, long int)
> +    void __builtin_loongarch_asrtgt_d (long int, long int)
> +    long int __builtin_loongarch_lddir_d (long int, imm0_31)
> +    void __builtin_loongarch_ldpte_d (long int, imm0_31)
> +
> +    int __builtin_loongarch_crc_w_b_w (char, int)
> +    int __builtin_loongarch_crc_w_h_w (short, int)
> +    int __builtin_loongarch_crc_w_w_w (int, int)
> +    int __builtin_loongarch_crc_w_d_w (long int, int)
> +    int __builtin_loongarch_crcc_w_b_w (char, int)
> +    int __builtin_loongarch_crcc_w_h_w (short, int)
> +    int __builtin_loongarch_crcc_w_w_w (int, int)
> +    int __builtin_loongarch_crcc_w_d_w (long int, int)
> +
> +    unsigned int __builtin_loongarch_csrrd_w (imm0_16383)
> +    unsigned int __builtin_loongarch_csrwr_w (unsigned int, imm0_16383)
> +    unsigned int __builtin_loongarch_csrxchg_w (unsigned int, unsigned int, imm0_16383)
> +    unsigned long int __builtin_loongarch_csrrd_d (imm0_16383)
> +    unsigned long int __builtin_loongarch_csrwr_d (unsigned long int, imm0_16383)
> +    unsigned long int __builtin_loongarch_csrxchg_d (unsigned long int, unsigned long int, imm0_16383)
> +
> +    unsigned char __builtin_loongarch_iocsrrd_b (unsigned int)
> +    unsigned short __builtin_loongarch_iocsrrd_h (unsigned int)
> +    unsigned int __builtin_loongarch_iocsrrd_w (unsigned int)
> +    unsigned long int __builtin_loongarch_iocsrrd_d (unsigned int)
> +    void __builtin_loongarch_iocsrwr_b (unsigned char, unsigned int)
> +    void __builtin_loongarch_iocsrwr_h (unsigned short, unsigned int)
> +    void __builtin_loongarch_iocsrwr_w (unsigned int, unsigned int)
> +    void __builtin_loongarch_iocsrwr_d (unsigned long int, unsigned int)
> +
> +    void __builtin_loongarch_dbar (imm0_32767)
> +    void __builtin_loongarch_ibar (imm0_32767)
> +
> +    void __builtin_loongarch_syscall (imm0_32767)
> +    void __builtin_loongarch_break (imm0_32767)
> +@end smallexample
> +
> +@emph{Note:}Since the control register is divided into 32-bit and 64-bit,
> +but the access instruction is not distinguished. So GCC renames the control
> +instructions when implementing intrinsics.
> +
> +Take the csrrd instruction as an example, built-in functions are implemented as follows:
> +@smallexample
> +  __builtin_loongarch_csrrd_w  // When reading the 32-bit control register use.
> +  __builtin_loongarch_csrrd_d  // When reading the 64-bit control register use.
> +@end smallexample
> +
> +For the convenience of use, the built-in functions are encapsulated,
> +the encapsulated functions and @code{__drdtime_t, __rdtime_t} are
> +defined in the @code{larchintrin.h}. So if you call the following
> +function you need to include @code{larchintrin.h}.
> +
> +@smallexample
> +     typedef struct drdtime@{
> +            unsigned long dvalue;
> +            unsigned long dtimeid;
> +     @} __drdtime_t;
> +
> +     typedef struct rdtime@{
> +            unsigned int value;
> +            unsigned int timeid;
> +     @} __rdtime_t;
> +@end smallexample
> +
> +@smallexample
> +    __drdtime_t __rdtime_d (void)
> +    __rdtime_t  __rdtimel_w (void)
> +    __rdtime_t  __rdtimeh_w (void)
> +    unsigned int  __movfcsr2gr (imm0_31)
> +    void __movgr2fcsr (imm0_31, unsigned int)
> +    void __cacop_d (imm0_31, unsigned long, imm_n2048_2047)
> +    unsigned int  __cpucfg (unsigned int)
> +    void __asrtle_d (long int, long int)
> +    void __asrtgt_d (long int, long int)
> +    long int  __lddir_d (long int, imm0_31)
> +    void __ldpte_d (long int, imm0_31)
> +
> +    int  __crc_w_b_w (char, int)
> +    int  __crc_w_h_w (short, int)
> +    int  __crc_w_w_w (int, int)
> +    int  __crc_w_d_w (long int, int)
> +    int  __crcc_w_b_w (char, int)
> +    int  __crcc_w_h_w (short, int)
> +    int  __crcc_w_w_w (int, int)
> +    int  __crcc_w_d_w (long int, int)
> +
> +    unsigned int  __csrrd_w (imm0_16383)
> +    unsigned int  __csrwr_w (unsigned int, imm0_16383)
> +    unsigned int  __csrxchg_w (unsigned int, unsigned int, imm0_16383)
> +    unsigned long  __csrrd_d (imm0_16383)
> +    unsigned long  __csrwr_d (unsigned long, imm0_16383)
> +    unsigned long  __csrxchg_d (unsigned long, unsigned long, imm0_16383)
> +
> +    unsigned char   __iocsrrd_b (unsigned int)
> +    unsigned short  __iocsrrd_h (unsigned int)
> +    unsigned int  __iocsrrd_w (unsigned int)
> +    unsigned long  __iocsrrd_d (unsigned int)
> +    void __iocsrwr_b (unsigned char, unsigned int)
> +    void __iocsrwr_h (unsigned short, unsigned int)
> +    void __iocsrwr_w (unsigned int, unsigned int)
> +    void __iocsrwr_d (unsigned long, unsigned int)
> +
> +    void __dbar (imm0_32767)
> +    void __ibar (imm0_32767)
> +
> +    void __syscall (imm0_32767)
> +    void __break (imm0_32767)
> +@end smallexample
> +
>   @node MIPS DSP Built-in Functions
>   @subsection MIPS DSP Built-in Functions
>