From e28af6a0029fc270f8f99a1649d29989f916b921 Mon Sep 17 00:00:00 2001
From: Alexey Lapshin <alexey.lapshin@espressif.com>
Date: Thu, 1 May 2025 13:35:20 +0700
Subject: [PATCH] fix(newlib): use optimized misalign access functions from
 libc.a

---
 components/newlib/CMakeLists.txt              | 41 ++++++++++---------
 ...sp32-spiram-rom-functions-c.lf => libc.lf} |  6 +--
 components/newlib/src/newlib.lf               | 15 +++++++
 ...sp32-spiram-rom-functions-c.lf => libc.lf} |  4 ++
 4 files changed, 42 insertions(+), 24 deletions(-)
 rename components/newlib/src/{esp32-spiram-rom-functions-c.lf => libc.lf} (97%)
 rename components/newlib/src/picolibc/{esp32-spiram-rom-functions-c.lf => libc.lf} (96%)

diff --git a/components/newlib/CMakeLists.txt b/components/newlib/CMakeLists.txt
index 99a11e810f..3d4769ca67 100644
--- a/components/newlib/CMakeLists.txt
+++ b/components/newlib/CMakeLists.txt
@@ -38,20 +38,23 @@ if(CONFIG_STDATOMIC_S32C1I_SPIRAM_WORKAROUND)
 endif()
 
 if(CONFIG_LIBC_OPTIMIZED_MISALIGNED_ACCESS)
-    list(APPEND srcs
-         "src/string/memcmp.c"
-         "src/string/memmove.c"
-         "src/string/strncmp.c"
-         "src/string/strncpy.c"
-         "src/port/riscv/memcpy.c"
-         "src/port/riscv/strcpy.c"
-         "src/port/riscv/strcmp.S")
-    list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_memcmp_impl")
-    list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_memmove_impl")
-    list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strncmp_impl")
-    list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strncpy_impl")
-    list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strcpy_impl")
-    list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strcmp_impl")
+    if(CMAKE_C_COMPILER_ID MATCHES "Clang")
+        # TODO IDF-13089: remove this block and modify src/newlib.lf when clang was upgraded
+        list(APPEND srcs
+             "src/string/memcmp.c"
+             "src/string/memmove.c"
+             "src/string/strncmp.c"
+             "src/string/strncpy.c"
+             "src/port/riscv/memcpy.c"
+             "src/port/riscv/strcpy.c"
+             "src/port/riscv/strcmp.S")
+        list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_memcmp_impl")
+        list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_memmove_impl")
+        list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strncmp_impl")
+        list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strncpy_impl")
+        list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strcpy_impl")
+        list(APPEND EXTRA_LINK_FLAGS "-u esp_libc_include_strcmp_impl")
+    endif()
 endif()
 
 if(CONFIG_LIBC_NEWLIB)
@@ -69,12 +72,10 @@ endif()
 set(ldfragments "")
 list(APPEND ldfragments "src/newlib.lf" "src/system_libs.lf")
 
-if(CONFIG_SPIRAM_CACHE_WORKAROUND)
-    if(CONFIG_LIBC_NEWLIB)
-        list(APPEND ldfragments src/esp32-spiram-rom-functions-c.lf)
-    else()
-        list(APPEND ldfragments src/picolibc/esp32-spiram-rom-functions-c.lf)
-    endif()
+if(CONFIG_LIBC_NEWLIB)
+    list(APPEND ldfragments src/libc.lf)
+else()
+    list(APPEND ldfragments src/picolibc/libc.lf)
 endif()
 
 idf_component_register(SRCS "${srcs}"
diff --git a/components/newlib/src/esp32-spiram-rom-functions-c.lf b/components/newlib/src/libc.lf
similarity index 97%
rename from components/newlib/src/esp32-spiram-rom-functions-c.lf
rename to components/newlib/src/libc.lf
index 1e066d61b1..1f31f191c1 100644
--- a/components/newlib/src/esp32-spiram-rom-functions-c.lf
+++ b/components/newlib/src/libc.lf
@@ -3,10 +3,6 @@
 # and/or applications may assume that because these functions normally are in ROM, they are accessible even when flash is
 # inaccessible. To work around this, this ld fragment places these functions in RAM instead. If the ROM functions are used,
 # these defines do nothing, so they can still be included in that situation.
-#
-#
-# Note: the only difference between esp32-spiram-rom-functions-c.lf
-# and esp32-spiram-rom-functions-psram-workaround.lf is the archive name.
 
 [mapping:libc]
 archive:
@@ -15,6 +11,8 @@ archive:
   else:
     libc.a
 entries:
+  if LIBC_OPTIMIZED_MISALIGNED_ACCESS = y:
+    libc_a-memcpy (noflash)
   if SPIRAM_CACHE_WORKAROUND = y:
     # The following libs are either used in a lot of places or in critical
     # code. (such as panic or abort)
diff --git a/components/newlib/src/newlib.lf b/components/newlib/src/newlib.lf
index 7ca47a0b9b..359acd6345 100644
--- a/components/newlib/src/newlib.lf
+++ b/components/newlib/src/newlib.lf
@@ -9,3 +9,18 @@ entries:
     stdatomic (noflash)
   if STDATOMIC_S32C1I_SPIRAM_WORKAROUND = y:
     stdatomic_s32c1i (noflash)
+  if STDATOMIC_S32C1I_SPIRAM_WORKAROUND = y:
+    stdatomic_s32c1i (noflash)
+  if CONFIG_LIBC_OPTIMIZED_MISALIGNED_ACCESS = y && IDF_TOOLCHAIN_GCC = y:
+    # memcpy() should be in IRAM due to early system use
+    # Others can stay in flash (performance difference is minimal)
+    #
+    # Performance Comparison:
+    # | func    | flash | iram  |
+    # |---------|-------|-------|
+    # | memcmp  | 15986 | 15170 |
+    # | strcpy  | 17499 | 16660 |
+    # | strcmp  | 13125 | 11147 |
+    # | strncpy | 17386 | 16668 |
+    # | strncmp | 22161 | 21782 |
+    libc_a-memcpy (noflash)
diff --git a/components/newlib/src/picolibc/esp32-spiram-rom-functions-c.lf b/components/newlib/src/picolibc/libc.lf
similarity index 96%
rename from components/newlib/src/picolibc/esp32-spiram-rom-functions-c.lf
rename to components/newlib/src/picolibc/libc.lf
index f2a97b4cc9..0892557473 100644
--- a/components/newlib/src/picolibc/esp32-spiram-rom-functions-c.lf
+++ b/components/newlib/src/picolibc/libc.lf
@@ -8,6 +8,10 @@
 archive:
     libc.a
 entries:
+  if LIBC_OPTIMIZED_MISALIGNED_ACCESS = y && IDF_TARGET_ARCH_RISCV = y:
+    memcpy-asm (noflash)
+  if LIBC_OPTIMIZED_MISALIGNED_ACCESS = y && IDF_TARGET_ARCH_XTENSA = y:
+    libc_machine_xtensa_memcpy (noflash)
   if SPIRAM_CACHE_WORKAROUND = y:
     # The following libs are either used in a lot of places or in critical code. (such as panic or abort)
     # Thus, they shall always be placed in IRAM.