ggml-cpu: add ggml_thread_cpu_relax with Zihintpause support (llama/17784)

* ggml-cpu: add ggml_thread_cpu_relax with Zihintpause support

Signed-off-by: Wang Yang <redacted>
* cmake: enable RISC-V zihintpause extension for Spacemit builds

* readme : add ZIHINTPAUSE support for RISC-V

---------

Signed-off-by: Wang Yang <redacted>

diff --git a/ggml/CMakeLists.txt b/ggml/CMakeLists.txt
index 6b69ad8281252c64cf23421a04cade3d431813d1..ab5b4760e20e56ad7b2dbd2da0337ff7777be35d 100644 (file)
--- a/ggml/CMakeLists.txt
+++ b/ggml/CMakeLists.txt
@@ -168,6 +168,7 @@ option(GGML_RVV              "ggml: enable rvv"              ON)
 option(GGML_RV_ZFH           "ggml: enable riscv zfh"        ON)
 option(GGML_RV_ZVFH          "ggml: enable riscv zvfh"       ON)
 option(GGML_RV_ZICBOP        "ggml: enable riscv zicbop"     ON)
+option(GGML_RV_ZIHINTPAUSE   "ggml: enable riscv zihintpause "  ON)
 option(GGML_XTHEADVECTOR     "ggml: enable xtheadvector"     OFF)
 option(GGML_VXE              "ggml: enable vxe"              ${GGML_NATIVE})
 

diff --git a/ggml/src/ggml-cpu/CMakeLists.txt b/ggml/src/ggml-cpu/CMakeLists.txt
index 7e53a57b7b010e9e096c67a3fcc4a6755c08d8c1..fc31089f3e23072a33c3e1f31c06e7d9181c6537 100644 (file)
--- a/ggml/src/ggml-cpu/CMakeLists.txt
+++ b/ggml/src/ggml-cpu/CMakeLists.txt
@@ -469,6 +469,9 @@ function(ggml_add_cpu_backend_variant_impl tag_name)
             if (GGML_RV_ZICBOP)
                 string(APPEND MARCH_STR "_zicbop")
             endif()
+            if (GGML_RV_ZIHINTPAUSE)
+                string(APPEND MARCH_STR "_zihintpause")
+            endif()
             list(APPEND ARCH_FLAGS "-march=${MARCH_STR}" -mabi=lp64d)
         else()
             # Begin with the lowest baseline

diff --git a/ggml/src/ggml-cpu/ggml-cpu.c b/ggml/src/ggml-cpu/ggml-cpu.c
index 8507557267a30fc07df912a4d95cb58a8fdba17c..b468b115a18f6c1bfee46231224a00293e41c8e1 100644 (file)
--- a/ggml/src/ggml-cpu/ggml-cpu.c
+++ b/ggml/src/ggml-cpu/ggml-cpu.c
@@ -490,6 +490,15 @@ static inline void ggml_thread_cpu_relax(void) {
 static inline void ggml_thread_cpu_relax(void) {
     _mm_pause();
 }
+#elif defined(__riscv)
+static inline void ggml_thread_cpu_relax(void) {
+    #ifdef __riscv_zihintpause
+        __asm__ __volatile__ ("pause");
+    #else
+        /* Encoding of the pause instruction */
+        __asm__ __volatile__ (".4byte 0x100000F");
+    #endif
+}
 #else
 static inline void ggml_thread_cpu_relax(void) {;}
 #endif