Revert "[AArch64][compiler-rt] Add memcpy, memset, memmove, memchr builtins."upstream/revert-77496-compiler-rt-sme-libc-routines

7 files changed, 5 insertions, 220 deletions

diff --git a/compiler-rt/cmake/builtin-config-ix.cmake b/compiler-rt/cmake/builtin-config-ix.cmake
index b17c43bf6a68..b40138aa011f 100644
--- a/compiler-rt/cmake/builtin-config-ix.cmake
+++ b/compiler-rt/cmake/builtin-config-ix.cmake
@@ -35,12 +35,10 @@ asm(\".arch armv8-a+lse\");
 asm(\"cas w0, w1, [x2]\");
 ")
 
-builtin_check_c_compiler_source(COMPILER_RT_HAS_AARCH64_SME
+builtin_check_c_compiler_source(COMPILER_RT_HAS_ASM_SME
 "
-void foo(void)  __arm_streaming_compatible {
-  asm(\".arch armv9-a+sme\");
-  asm(\"smstart\");
-}
+asm(\".arch armv9-a+sme\");
+asm(\"smstart\");
 ")
 
 if(ANDROID)
diff --git a/compiler-rt/lib/builtins/CMakeLists.txt b/compiler-rt/lib/builtins/CMakeLists.txt
index 28ded8766f25..378884bcaf2e 100644
--- a/compiler-rt/lib/builtins/CMakeLists.txt
+++ b/compiler-rt/lib/builtins/CMakeLists.txt
@@ -560,10 +560,9 @@ set(aarch64_SOURCES
   aarch64/fp_mode.c
 )
 
-if(COMPILER_RT_HAS_AARCH64_SME AND COMPILER_RT_HAS_FNO_BUILTIN_FLAG AND (COMPILER_RT_HAS_AUXV OR COMPILER_RT_BAREMETAL_BUILD))
-  list(APPEND aarch64_SOURCES aarch64/sme-abi.S aarch64/sme-abi-init.c aarch64/sme-libc-routines.c)
+if(COMPILER_RT_HAS_ASM_SME AND (COMPILER_RT_HAS_AUXV OR COMPILER_RT_BAREMETAL_BUILD))
+  list(APPEND aarch64_SOURCES aarch64/sme-abi.S aarch64/sme-abi-init.c)
   message(STATUS "AArch64 SME ABI routines enabled")
-  set_source_files_properties(aarch64/sme-libc-routines.c PROPERTIES COMPILE_FLAGS "-fno-builtin")
 else()
   message(STATUS "AArch64 SME ABI routines disabled")
 endif()
diff --git a/compiler-rt/lib/builtins/aarch64/sme-libc-routines.c b/compiler-rt/lib/builtins/aarch64/sme-libc-routines.c
deleted file mode 100644
index cd73025a19cc..000000000000
--- a/compiler-rt/lib/builtins/aarch64/sme-libc-routines.c
+++ /dev/null
@@ -1,87 +0,0 @@
-#include <stdlib.h>
-
-// WARNING: When building the scalar versions of these functions you need to
-// use the compiler flag "-mllvm -disable-loop-idiom-all" to prevent clang
-// from recognising a loop idiom and planting calls to memcpy!
-
-static void *__arm_sc_memcpy_fwd(void *dest, const void *src,
-                                 size_t n) __arm_streaming_compatible {
-  unsigned char *destp = (unsigned char *)dest;
-  const unsigned char *srcp = (const unsigned char *)src;
-  for (size_t i = 0; i < n; ++i)
-    destp[i] = srcp[i];
-
-  return dest;
-}
-
-// If dest and src overlap then behaviour is undefined, hence we can add the
-// restrict keywords here. This also matches the definition of the libc memcpy
-// according to the man page.
-void *__arm_sc_memcpy(void *__restrict__ dest, const void *__restrict__ src,
-                      size_t n) __arm_streaming_compatible {
-  return __arm_sc_memcpy_fwd(dest, src, n);
-}
-
-void *__arm_sc_memset(void *dest, int c, size_t n) __arm_streaming_compatible {
-  unsigned char *destp = (unsigned char *)dest;
-  unsigned char c8 = (unsigned char)c;
-  for (size_t i = 0; i < n; ++i)
-    destp[i] = c8;
-
-  return dest;
-}
-
-static void *__arm_sc_memcpy_rev(void *dest, const void *src,
-                                 size_t n) __arm_streaming_compatible {
-  unsigned char *destp = (unsigned char *)dest;
-  const unsigned char *srcp = (const unsigned char *)src;
-  // TODO: Improve performance by copying larger chunks in reverse, or by
-  // using SVE.
-  while (n > 0) {
-    --n;
-    destp[n] = srcp[n];
-  }
-  return dest;
-}
-
-// Semantically a memmove is equivalent to the following:
-//   1. Copy the entire contents of src to a temporary array that does not
-//      overlap with src or dest.
-//   2. Copy the contents of the temporary array into dest.
-void *__arm_sc_memmove(void *dest, const void *src,
-                       size_t n) __arm_streaming_compatible {
-  unsigned char *destp = (unsigned char *)dest;
-  const unsigned char *srcp = (const unsigned char *)src;
-
-  // If src and dest don't overlap then just invoke memcpy
-  if ((srcp > (destp + n)) || (destp > (srcp + n)))
-    return __arm_sc_memcpy_fwd(dest, src, n);
-
-  // Overlap case 1:
-  //     src: Low     |   ->   |     High
-  //    dest: Low  |   ->   |        High
-  // Here src is always ahead of dest at a higher addres. If we first read a
-  // chunk of data from src we can safely write the same chunk to dest without
-  // corrupting future reads of src.
-  if (srcp > destp)
-    return __arm_sc_memcpy_fwd(dest, src, n);
-
-  // Overlap case 2:
-  //     src: Low  |   ->   |        High
-  //    dest: Low     |   ->   |     High
-  // While we're in the overlap region we're always corrupting future reads of
-  // src when writing to dest. An efficient way to do this is to copy the data
-  // in reverse by starting at the highest address.
-  return __arm_sc_memcpy_rev(dest, src, n);
-}
-
-const void *__arm_sc_memchr(const void *src, int c,
-                            size_t n) __arm_streaming_compatible {
-  const unsigned char *srcp = (const unsigned char *)src;
-  unsigned char c8 = (unsigned char)c;
-  for (size_t i = 0; i < n; ++i)
-    if (srcp[i] == c8)
-      return &srcp[i];
-
-  return NULL;
-}
diff --git a/compiler-rt/test/builtins/Unit/sme-string-test.cpp b/compiler-rt/test/builtins/Unit/sme-string-test.cpp
deleted file mode 100644
index 3bc4559f9ae0..000000000000
--- a/compiler-rt/test/builtins/Unit/sme-string-test.cpp
+++ /dev/null
@@ -1,120 +0,0 @@
-// REQUIRES: aarch64-target-arch, aarch64-sme-available
-// RUN: %clangxx_builtins %s %librt -o %t && %run %t
-
-#include <cassert>
-#include <initializer_list>
-#include <stdint.h>
-#include <stdlib.h>
-#include <string.h>
-
-extern "C" {
-void *__arm_sc_memcpy(void *, const void *, size_t);
-void *__arm_sc_memset(void *, int, size_t);
-void *__arm_sc_memmove(void *, const void *, size_t);
-void *__arm_sc_memchr(const void *, int, size_t);
-}
-
-template <unsigned N> class Memory {
-public:
-  uint8_t ptr[N];
-  unsigned size;
-
-  Memory(unsigned stride = 0) {
-    size = N;
-    if (stride == 0)
-      return;
-    for (unsigned i = 0; i < N; i++)
-      ptr[i] = i * stride;
-  }
-
-  void assert_equal(const Memory &other) {
-    assert(N == other.size);
-    assert(memcmp(ptr, other.ptr, N) == 0);
-  }
-
-  void assert_equal(std::initializer_list<uint8_t> s) {
-    assert(N == s.size());
-    auto it = s.begin();
-    for (unsigned i = 0; i < N; ++i)
-      assert(ptr[i] == *it++);
-  }
-
-  void assert_elemt_equal_at(unsigned I, uint8_t elem) {
-    assert(ptr[I] == elem);
-  }
-};
-
-int main() {
-
-  // Testing memcpy from src to dst.
-  {
-    Memory<8> src(1);
-    Memory<8> dst;
-    if (!__arm_sc_memcpy(dst.ptr, src.ptr, 8))
-      abort();
-    dst.assert_equal(src);
-    dst.assert_equal({0, 1, 2, 3, 4, 5, 6, 7});
-  }
-
-  // Testing memcpy from src to dst with pointer offset.
-  {
-    Memory<8> src(1);
-    Memory<8> dst(1);
-    if (!__arm_sc_memcpy(dst.ptr + 1, src.ptr, 6))
-      abort();
-    dst.assert_equal({0, 0, 1, 2, 3, 4, 5, 7});
-  }
-
-  // Testing memchr.
-  {
-    Memory<8> src(4);
-    for (unsigned i = 0; i < 8; ++i) {
-      uint8_t e = src.ptr[i];
-      uint8_t *elem = (uint8_t *)memchr(src.ptr, e, 8);
-      if (!elem)
-        abort();
-      src.assert_elemt_equal_at(elem - src.ptr, *elem);
-      for (unsigned i = 0; i < 8; ++i)
-        assert(__arm_sc_memchr(src.ptr, src.ptr[i], 8) ==
-               memchr(src.ptr, src.ptr[i], 8));
-    }
-  }
-
-  // Testing memset.
-  {
-    Memory<8> array;
-    if (!__arm_sc_memset(array.ptr, 2, 8))
-      abort();
-    array.assert_equal({2, 2, 2, 2, 2, 2, 2, 2});
-  }
-
-  // Testing memset with pointer offset.
-  {
-    Memory<8> array(1);
-    if (!__arm_sc_memset(array.ptr + 1, 2, 6))
-      abort();
-    array.assert_equal({0, 2, 2, 2, 2, 2, 2, 7});
-  }
-
-  // Testing memmove with a simple non-overlap case.
-  {
-    Memory<8> src(1);
-    Memory<8> dst(1);
-    if (!__arm_sc_memmove(dst.ptr + 1, src.ptr, 6))
-      abort();
-    dst.assert_equal({0, 0, 1, 2, 3, 4, 5, 7});
-  }
-
-  // Testing memove with overlap pointers dst > src, dst < src.
-  {
-    Memory<8> srcdst(1);
-    if (!__arm_sc_memmove(srcdst.ptr + 1, srcdst.ptr, 6))
-      abort();
-    srcdst.assert_equal({0, 0, 1, 2, 3, 4, 5, 7});
-    if (!__arm_sc_memmove(srcdst.ptr, srcdst.ptr + 1, 6))
-      abort();
-    srcdst.assert_equal({0, 1, 2, 3, 4, 5, 5, 7});
-  }
-
-  return 0;
-}
diff --git a/compiler-rt/test/lit.common.cfg.py b/compiler-rt/test/lit.common.cfg.py
index 113777b0ea8a..1753a55508c7 100644
--- a/compiler-rt/test/lit.common.cfg.py
+++ b/compiler-rt/test/lit.common.cfg.py
@@ -454,9 +454,6 @@ if not getattr(config, "sanitizer_uses_static_unwind", False):
 if config.has_lld:
     config.available_features.add("lld-available")
 
-if config.aarch64_sme:
-    config.available_features.add("aarch64-sme-available")
-
 if config.use_lld:
     config.available_features.add("lld")
 
diff --git a/compiler-rt/test/lit.common.configured.in b/compiler-rt/test/lit.common.configured.in
index b93e20e80a6e..7c2d53520099 100644
--- a/compiler-rt/test/lit.common.configured.in
+++ b/compiler-rt/test/lit.common.configured.in
@@ -50,7 +50,6 @@ set_default("gwp_asan", @COMPILER_RT_HAS_GWP_ASAN_PYBOOL@)
 set_default("expensive_checks", @LLVM_ENABLE_EXPENSIVE_CHECKS_PYBOOL@)
 set_default("test_standalone_build_libs", @COMPILER_RT_TEST_STANDALONE_BUILD_LIBS_PYBOOL@)
 set_default("has_compiler_rt_libatomic", @COMPILER_RT_BUILD_STANDALONE_LIBATOMIC_PYBOOL@)
-set_default("aarch64_sme", @COMPILER_RT_HAS_AARCH64_SME@)
 # True iff the test suite supports ignoring the test compiler's runtime library path
 # and using `config.compiler_rt_libdir` instead. This only matters when the runtime
 # library paths differ.
diff --git a/compiler-rt/unittests/lit.common.unit.configured.in b/compiler-rt/unittests/lit.common.unit.configured.in
index 0d4785e0f038..3e42e83c9e70 100644
--- a/compiler-rt/unittests/lit.common.unit.configured.in
+++ b/compiler-rt/unittests/lit.common.unit.configured.in
@@ -7,7 +7,6 @@ config.llvm_obj_root = "@LLVM_BINARY_DIR@"
 config.llvm_tools_dir = lit_config.substitute("@LLVM_TOOLS_DIR@")
 config.compiler_rt_src_root = "@COMPILER_RT_SOURCE_DIR@"
 config.compiler_rt_libdir = lit_config.substitute("@COMPILER_RT_RESOLVED_LIBRARY_OUTPUT_DIR@")
-config.aarch64_sme = "@COMPILER_RT_HAS_AARCH64_SME@"
 config.enable_per_target_runtime_dir = @LLVM_ENABLE_PER_TARGET_RUNTIME_DIR_PYBOOL@
 config.llvm_build_mode = lit_config.substitute("@LLVM_BUILD_MODE@")
 config.host_arch = "@HOST_ARCH@"