[PATCH 6/6] riscv: add vectorized rawmemchr

The vector implementation uses m8 register grouping and processes data in
vector-length chunks, providing significant performance improvements on
RVV-capable hardware.  Use conditional compilation to fall back to the
generic implementation when __riscv_vector is not available, maintaining
compatibility with non-vector RISC-V systems.

Signed-off-by: Pincheng Wang <[email protected]>
---
 newlib/libc/machine/riscv/Makefile.inc    |  2 ++
 newlib/libc/machine/riscv/rawmemchr-asm.S | 30 +++++++++++++++++++++++
 newlib/libc/machine/riscv/rawmemchr.c     |  5 ++++
 3 files changed, 37 insertions(+)
 create mode 100644 newlib/libc/machine/riscv/rawmemchr-asm.S
 create mode 100644 newlib/libc/machine/riscv/rawmemchr.c

diff --git a/newlib/libc/machine/riscv/Makefile.inc b/newlib/libc/machine/riscv/Makefile.inc
index 086150e45..feda2b850 100644
--- a/newlib/libc/machine/riscv/Makefile.inc
+++ b/newlib/libc/machine/riscv/Makefile.inc
@@ -16,6 +16,8 @@ libc_a_SOURCES += \
         %D%/memrchr-asm.S \
         %D%/memrchr.c \
         %D%/memset.S \
+        %D%/rawmemchr-asm.S \
+        %D%/rawmemchr.c \
         %D%/setjmp.S \
         %D%/stpcpy.c \
         %D%/strcmp.S \
diff --git a/newlib/libc/machine/riscv/rawmemchr-asm.S b/newlib/libc/machine/riscv/rawmemchr-asm.S
new file mode 100644
index 000000000..adec7dd40
--- /dev/null
+++ b/newlib/libc/machine/riscv/rawmemchr-asm.S
@@ -0,0 +1,30 @@
+#if defined(__riscv_vector) && !defined(__OPTIMIZE_SIZE__) && !defined(PREFER_SIZE_OVER_SPEED)
+.text
+.option push
+.option arch, +zve32x
+.global rawmemchr
+.type rawmemchr, @function
+rawmemchr:
+#if __riscv_landing_pad
+  lpad 0
+#endif
+  andi a1, a1, 0xff
+.Lloop:
+  vsetvli t0, zero, e8, m8, ta, ma
+
+  vle8ff.v v0, (a0)
+  vmseq.vx v8, v0, a1
+  vfirst.m a2, v8
+
+  bgez a2, .Lfound
+
+  csrr a3, vl
+  add a0, a0, a3
+  j .Lloop
+
+.Lfound:
+  add a0, a0, a2
+  ret
+.size rawmemchr, .-rawmemchr
+.option pop
+#endif
diff --git a/newlib/libc/machine/riscv/rawmemchr.c b/newlib/libc/machine/riscv/rawmemchr.c
new file mode 100644
index 000000000..00c1da679
--- /dev/null
+++ b/newlib/libc/machine/riscv/rawmemchr.c
@@ -0,0 +1,5 @@
+#if defined(__OPTIMIZE_SIZE__) || defined(PREFER_SIZE_OVER_SPEED) || !defined(__riscv_vector)
+# include "../../string/rawmemchr.c"
+#else
+/* rawmemchr defined in rawmemchr-asm.S */
+#endif
-- 
2.39.5