From: alexsifivetw <alex.chiang@sifive.com>
Date: Thu, 31 Aug 2023 08:22:20 +0000 (-0700)
Subject: General optimized chunkset
X-Git-Tag: 2.1.4~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fe6aaedaf8be680d43d5726a2e2b3ed948406800;p=thirdparty%2Fzlib-ng.git

General optimized chunkset
---

diff --git a/CMakeLists.txt b/CMakeLists.txt
index bf0423b95..b7dc46be0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -739,7 +739,7 @@ if(WITH_OPTIM)
                 list(APPEND ZLIB_ARCH_SRCS ${ARCHDIR}/riscv_features.c)
                 # FIXME: we will not set compile flags for riscv_features.c when
                 # the kernels update hwcap or hwprobe for riscv
-                set(RVV_SRCS ${ARCHDIR}/riscv_features.c ${ARCHDIR}/adler32_rvv.c ${ARCHDIR}/compare256_rvv.c ${ARCHDIR}/slide_hash_rvv.c)
+                set(RVV_SRCS ${ARCHDIR}/riscv_features.c ${ARCHDIR}/adler32_rvv.c ${ARCHDIR}/chunkset_rvv.c ${ARCHDIR}/compare256_rvv.c ${ARCHDIR}/slide_hash_rvv.c)
                 list(APPEND ZLIB_ARCH_SRCS ${RVV_SRCS})
                 set_property(SOURCE ${RVV_SRCS} PROPERTY COMPILE_FLAGS "${RISCVFLAG} ${NOLTOFLAG}")
             else()
diff --git a/arch/riscv/chunkset_rvv.c b/arch/riscv/chunkset_rvv.c
new file mode 100644
index 000000000..034063ba2
--- /dev/null
+++ b/arch/riscv/chunkset_rvv.c
@@ -0,0 +1,95 @@
+/* chunkset_rvv.c - General version of chunkset
+ * Copyright (C) 2023 SiFive, Inc. All rights reserved.
+ * Contributed by Alex Chiang <alex.chiang@sifive.com>
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+#include "zbuild.h"
+
+/*
+ * It's not a optimized implemantation using RISC-V RVV, but a general optimized one.
+ *
+ * RISC-V glibc would enable RVV optimized memcpy at runtime by IFUNC,
+ * so we prefer using large size chunk and copy memory as much as possible.
+ */
+#define CHUNK_SIZE 32
+
+/* We don't have a 32-byte datatype for RISC-V arch. */
+typedef struct chunk_s {
+    uint8_t data[CHUNK_SIZE];
+} chunk_t;
+
+static inline void loadchunk(uint8_t const *s, chunk_t *chunk) {
+    memcpy(chunk->data, s, CHUNK_SIZE);
+}
+
+static inline void storechunk(uint8_t *out, chunk_t *chunk) {
+    memcpy(out, chunk->data, CHUNK_SIZE);
+}
+
+#define CHUNKSIZE        chunksize_rvv
+#define CHUNKCOPY        chunkcopy_rvv
+#define CHUNKUNROLL      chunkunroll_rvv
+#define CHUNKMEMSET      chunkmemset_rvv
+#define CHUNKMEMSET_SAFE chunkmemset_safe_rvv
+
+#define HAVE_CHUNKCOPY
+
+/*
+ * Assuming that the length is non-zero, and that `from` lags `out` by at least
+ * sizeof chunk_t bytes, please see the comments in chunkset_tpl.h.
+ *
+ * We load/store a single chunk once in the `CHUNKCOPY`.
+ * However, RISC-V glibc would enable RVV optimized memcpy at runtime by IFUNC,
+ * such that, we prefer copy large memory size once to make good use of the the RVV advance.
+ * 
+ * To be aligned to the other platforms, we did't modify `CHUNKCOPY` method a lot,
+ * but we still copy as much memory as possible for some conditions.
+ * 
+ * case 1: out - from >= len (no overlap)
+ *         We can use memcpy to copy `len` size once
+ *         because the memory layout would be the same.
+ *
+ * case 2: overlap
+ *         We copy N chunks using memcpy at once, aiming to achieve our goal: 
+ *         to copy as much memory as possible.
+ * 
+ *         After using a single memcpy to copy N chunks, we have to use series of
+ *         loadchunk and storechunk to ensure the result is correct.
+ */
+static inline uint8_t* CHUNKCOPY(uint8_t *out, uint8_t const *from, unsigned len) {
+    Assert(len > 0, "chunkcopy should never have a length 0");
+    int32_t align = ((len - 1) % sizeof(chunk_t)) + 1;
+    chunk_t chunk;
+    memcpy(out, from, sizeof(chunk));
+    out += align;
+    from += align;
+    len -= align;
+    ptrdiff_t dist = out - from;
+    if (dist >= len) {
+        memcpy(out, from, len);
+        out += len;
+        from += len;
+        return out;
+    }
+    if (dist >= sizeof(chunk_t)) {
+        dist = (dist / sizeof(chunk_t)) * sizeof(chunk_t);
+        memcpy(out, from, dist);
+        out += dist;
+        from += dist;
+        len -= dist;
+    }
+    while (len > 0) {
+        memcpy(out, from, sizeof(chunk));
+        out += sizeof(chunk_t);
+        from += sizeof(chunk_t);
+        len -= sizeof(chunk_t);
+    }
+    return out;
+}
+
+#include "chunkset_tpl.h"
+
+#define INFLATE_FAST     inflate_fast_rvv
+
+#include "inffast_tpl.h"
diff --git a/cpu_features.h b/cpu_features.h
index faca52ad4..aed1eaf90 100644
--- a/cpu_features.h
+++ b/cpu_features.h
@@ -121,6 +121,10 @@ extern uint8_t* chunkmemset_safe_neon(uint8_t *out, unsigned dist, unsigned len,
 extern uint32_t chunksize_power8(void);
 extern uint8_t* chunkmemset_safe_power8(uint8_t *out, unsigned dist, unsigned len, unsigned left);
 #endif
+#ifdef RISCV_RVV
+extern uint32_t chunksize_rvv(void);
+extern uint8_t* chunkmemset_safe_rvv(uint8_t *out, unsigned dist, unsigned len, unsigned left);
+#endif
 
 #ifdef ZLIB_COMPAT
 typedef struct z_stream_s z_stream;
@@ -145,6 +149,9 @@ extern void inflate_fast_neon(PREFIX3(stream) *strm, uint32_t start);
 #ifdef POWER8_VSX
 extern void inflate_fast_power8(PREFIX3(stream) *strm, uint32_t start);
 #endif
+#ifdef RISCV_RVV
+extern void inflate_fast_rvv(PREFIX3(stream) *strm, uint32_t start);
+#endif
 
 /* CRC32 */
 typedef uint32_t (*crc32_func)(uint32_t crc32, const uint8_t *buf, size_t len);
diff --git a/functable.c b/functable.c
index 3ef840cff..df35bae7c 100644
--- a/functable.c
+++ b/functable.c
@@ -215,7 +215,10 @@ static void init_functable(void) {
 #ifdef RISCV_RVV
     if (cf.riscv.has_rvv) {
         ft.adler32 = &adler32_rvv;
+        ft.chunkmemset_safe = &chunkmemset_safe_rvv;
+        ft.chunksize = &chunksize_rvv;
         ft.compare256 = &compare256_rvv;
+        ft.inflate_fast = &inflate_fast_rvv;
         ft.longest_match = &longest_match_rvv;
         ft.longest_match_slow = &longest_match_slow_rvv;
         ft.slide_hash = &slide_hash_rvv;