[PATCH] newlib: riscv: Add Zicfilp lpads to asm functions

[Kito Cheng]

Could you check __riscv_landing_pad instead of __riscv_zicfilp? that
will be defined only if the user enables landing pad gen :)

ethycS <arjun.salunkhe@proton.me> 於 2026年3月19日週四 下午4:54寫道：
>
> From 8ed7d5f2ad33de425a83eff6b1ad4d8c1a0a1108 Mon Sep 17 00:00:00 2001
> From: Arjun Salunkhe <arjun.salunkhe@proton.me>
> Date: Thu, 19 Mar 2026 13:50:54 +0530
> Subject: [PATCH] newlib: riscv: Add Zicfilp lpads to asm functions
>
> Adds `lpad 0` instructions, guarded by `#if __riscv_zicfilp`,
> to the RISC-V assembly memory, setjmp and string functions.
>
> Signed-off-by: Arjun Salunkhe <arjun.salunkhe@proton.me>
> ---
>  newlib/libc/machine/riscv/memcpy-asm.S  | 4 ++++
>  newlib/libc/machine/riscv/memmove-asm.S | 4 ++++
>  newlib/libc/machine/riscv/memset.S      | 4 ++++
>  newlib/libc/machine/riscv/setjmp.S      | 6 ++++++
>  newlib/libc/machine/riscv/strcmp.S      | 4 ++++
>  5 files changed, 22 insertions(+)
>
> diff --git a/newlib/libc/machine/riscv/memcpy-asm.S b/newlib/libc/machine/riscv/memcpy-asm.S
> index 2771285f9..c3d12fca7 100644
> --- a/newlib/libc/machine/riscv/memcpy-asm.S
> +++ b/newlib/libc/machine/riscv/memcpy-asm.S
> @@ -14,6 +14,10 @@
>  .global memcpy
>  .type  memcpy, @function
>  memcpy:
> +#if __riscv_zicfilp
> +  lpad 0
> +#endif
> +
>    mv a3, a0
>    beqz a2, 2f
>
> diff --git a/newlib/libc/machine/riscv/memmove-asm.S b/newlib/libc/machine/riscv/memmove-asm.S
> index 061472ca2..6fb6f6e91 100644
> --- a/newlib/libc/machine/riscv/memmove-asm.S
> +++ b/newlib/libc/machine/riscv/memmove-asm.S
> @@ -14,6 +14,10 @@
>  .global memmove
>  .type  memmove, @function
>  memmove:
> +#if __riscv_zicfilp
> +  lpad 0
> +#endif
> +
>    beqz a2, .Ldone              /* in case there are 0 bytes to be copied, return immediately */
>
>    mv a4, a0                    /* copy the destination address over to a4, since memmove should return that address in a0 at the end */
> diff --git a/newlib/libc/machine/riscv/memset.S b/newlib/libc/machine/riscv/memset.S
> index 533f66758..b922c7b6e 100644
> --- a/newlib/libc/machine/riscv/memset.S
> +++ b/newlib/libc/machine/riscv/memset.S
> @@ -50,6 +50,10 @@
>
>
>  memset:
> +#if __riscv_zicfilp
> +  lpad 0
> +#endif
> +
>  #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
>    mv     a3, a0
>    beqz   a2, .Ldone
> diff --git a/newlib/libc/machine/riscv/setjmp.S b/newlib/libc/machine/riscv/setjmp.S
> index f2b50537e..170928a63 100644
> --- a/newlib/libc/machine/riscv/setjmp.S
> +++ b/newlib/libc/machine/riscv/setjmp.S
> @@ -15,6 +15,9 @@
>    .globl  setjmp
>    .type   setjmp, @function
>  setjmp:
> +#if __riscv_zicfilp
> +  lpad 0
> +#endif
>         REG_S ra,  0*SZREG(a0)
>    #if __riscv_xlen == 32 && (__riscv_zilsd) && (__riscv_misaligned_fast)
>           sd    s0,  1*SZREG(a0)
> @@ -70,6 +73,9 @@ setjmp:
>    .globl  longjmp
>    .type   longjmp, @function
>  longjmp:
> +#if __riscv_zicfilp
> +  lpad 0
> +#endif
>         REG_L ra,  0*SZREG(a0)
>    #if __riscv_xlen == 32 && (__riscv_zilsd) && (__riscv_misaligned_fast)
>      ld s0, 1*SZREG(a0)
> diff --git a/newlib/libc/machine/riscv/strcmp.S b/newlib/libc/machine/riscv/strcmp.S
> index 0b1dfc4b1..e5d75abe9 100644
> --- a/newlib/libc/machine/riscv/strcmp.S
> +++ b/newlib/libc/machine/riscv/strcmp.S
> @@ -15,6 +15,10 @@
>  .globl strcmp
>  .type  strcmp, @function
>  strcmp:
> +#if __riscv_zicfilp
> +  lpad 0
> +#endif
> +
>  #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
>  .Lcompare:
>    lbu   a2, 0(a0)
> --
> 2.53.0