Revert D142108 "[reland][libc][NFC] Detect host CPU features using try_compile instead of try_run."

The build bots are failing. This reverts commit c84d74f5bf.
2024-10-07 19:03:57 +00:00 · 2023-01-24 16:22:26 +00:00 · 2023-01-24 16:22:26 +00:00 · 76f9a6a4e7
commit 76f9a6a4e7
parent 7c3a7c727b
24 changed files with 75 additions and 110 deletions
--- a/libc/cmake/modules/LLVMLibCCheckCpuFeatures.cmake
+++ b/libc/cmake/modules/LLVMLibCCheckCpuFeatures.cmake
@ -44,32 +44,44 @@ function(_intersection output_var list1 list2)
  set(${output_var} ${tmp} PARENT_SCOPE)
 endfunction()

-set(AVAILABLE_CPU_FEATURES "")
-if(LIBC_CROSSBUILD)
-  # If we are doing a cross build, we will just assume that all CPU features
-  # are available.
-  set(AVAILABLE_CPU_FEATURES ${ALL_CPU_FEATURES})
-else()
-  # Try compile a C file to check if flag is supported.
-  set(CMAKE_TRY_COMPILE_TARGET_TYPE STATIC_LIBRARY)
+# Generates a cpp file to introspect the compiler defined flags.
+function(_generate_check_code)
  foreach(feature IN LISTS ALL_CPU_FEATURES)
-    try_compile(
-      has_feature
-      ${CMAKE_CURRENT_BINARY_DIR}/cpu_features
-      SOURCES ${LIBC_SOURCE_DIR}/cmake/modules/cpu_features/check_${feature}.cpp
-      COMPILE_DEFINITIONS -I${LIBC_SOURCE_DIR} ${LIBC_COMPILE_OPTIONS_NATIVE}
-    )
-    if(has_feature)
-      list(APPEND AVAILABLE_CPU_FEATURES ${feature})
-    endif()
+    set(DEFINITIONS
+        "${DEFINITIONS}
+#ifdef __${feature}__
+    \"${feature}\",
+#endif")
  endforeach()
-endif()
+  configure_file(
+    "${LIBC_SOURCE_DIR}/cmake/modules/cpu_features/check_cpu_features.cpp.in"
+    "cpu_features/check_cpu_features.cpp" @ONLY)
+endfunction()
+_generate_check_code()

-set(LIBC_CPU_FEATURES ${AVAILABLE_CPU_FEATURES} CACHE STRING "Host supported CPU features")
+set(LIBC_CPU_FEATURES "" CACHE PATH "Host supported CPU features")

-_intersection(cpu_features "${AVAILABLE_CPU_FEATURES}" "${LIBC_CPU_FEATURES}")
-if(NOT "${cpu_features}" STREQUAL "${LIBC_CPU_FEATURES}")
-  message(FATAL_ERROR "Unsupported CPU features: ${cpu_features}")
-else()
+if(LIBC_CROSSBUILD)
+  _intersection(cpu_features "${ALL_CPU_FEATURES}" "${LIBC_CPU_FEATURES}")
+  if(NOT "${cpu_features}" STREQUAL "${LIBC_CPU_FEATURES}")
+    message(FATAL_ERROR "Unsupported CPU features: ${cpu_features}")
+  endif()
  message(STATUS "Set CPU features: ${cpu_features}")
+  set(LIBC_CPU_FEATURES "${cpu_features}")
+else()
+  # Populates the LIBC_CPU_FEATURES list from host.
+  try_run(
+    run_result compile_result "${CMAKE_CURRENT_BINARY_DIR}/check_${feature}"
+    "${CMAKE_CURRENT_BINARY_DIR}/cpu_features/check_cpu_features.cpp"
+    COMPILE_DEFINITIONS ${LIBC_COMPILE_OPTIONS_NATIVE}
+    COMPILE_OUTPUT_VARIABLE compile_output
+    RUN_OUTPUT_VARIABLE run_output)
+  if("${run_result}" EQUAL 0)
+    message(STATUS "Set CPU features: ${run_output}")
+    set(LIBC_CPU_FEATURES "${run_output}")
+  elseif(NOT ${compile_result})
+    message(FATAL_ERROR "Failed to compile: ${compile_output}")
+  else()
+    message(FATAL_ERROR "Failed to run: ${run_output}")
+  endif()
 endif()
--- a/libc/cmake/modules/cpu_features/check_AVX2.cpp
+++ b/libc/cmake/modules/cpu_features/check_AVX2.cpp
@ -1,5 +0,0 @@
-#include "src/__support/cpu_features.h"
-
-#ifndef LIBC_TARGET_HAS_AVX2
-#error unsupported
-#endif
--- a/libc/cmake/modules/cpu_features/check_AVX512BW.cpp
+++ b/libc/cmake/modules/cpu_features/check_AVX512BW.cpp
@ -1,5 +0,0 @@
-#include "src/__support/cpu_features.h"
-
-#ifndef LIBC_TARGET_HAS_AVX512BW
-#error unsupported
-#endif
--- a/libc/cmake/modules/cpu_features/check_AVX512F.cpp
+++ b/libc/cmake/modules/cpu_features/check_AVX512F.cpp
@ -1,5 +0,0 @@
-#include "src/__support/cpu_features.h"
-
-#ifndef LIBC_TARGET_HAS_AVX512F
-#error unsupported
-#endif
--- a/libc/cmake/modules/cpu_features/check_FMA.cpp
+++ b/libc/cmake/modules/cpu_features/check_FMA.cpp
@ -1,5 +0,0 @@
-#include "src/__support/cpu_features.h"
-
-#ifndef LIBC_TARGET_HAS_FMA
-#error unsupported
-#endif
--- a/libc/cmake/modules/cpu_features/check_SSE2.cpp
+++ b/libc/cmake/modules/cpu_features/check_SSE2.cpp
@ -1,5 +0,0 @@
-#include "src/__support/cpu_features.h"
-
-#ifndef LIBC_TARGET_HAS_SSE2
-#error unsupported
-#endif
--- a/libc/cmake/modules/cpu_features/check_SSE4_2.cpp
+++ b/libc/cmake/modules/cpu_features/check_SSE4_2.cpp
@ -1,5 +0,0 @@
-#include "src/__support/cpu_features.h"
-
-#ifndef LIBC_TARGET_HAS_SSE4_2
-#error unsupported
-#endif
--- a/libc/cmake/modules/cpu_features/check_cpu_features.cpp.in
+++ b/libc/cmake/modules/cpu_features/check_cpu_features.cpp.in
@ -0,0 +1,32 @@
+#include <stdio.h>
+#include <stdlib.h>
+
+// This file is instantiated by CMake.
+// DEFINITIONS below is replaced with a set of lines like so:
+//   #ifdef __SSE2__
+//     "SSE2",
+//   #endif
+//
+// This allows for introspection of compiler definitions.
+// The output of the program is a single line of semi colon separated feature
+// names.
+
+// MSVC is using a different set of preprocessor definitions for 
+// SSE and SSE2, see _M_IX86_FP in
+// https://docs.microsoft.com/en-us/cpp/preprocessor/predefined-macros
+
+int main(int, char **) {
+  const char *strings[] = {
+      @DEFINITIONS@
+      // If DEFINITIONS turns out to be empty, we don't want to list
+      // an empty array. So, we add an end of list marker.
+      "<end_of_feature_list>"
+  };
+  const size_t size = sizeof(strings) / sizeof(strings[0]);
+  for (size_t i = 0; i < size; ++i) {
+    if (i)
+      putchar(';');
+    fputs(strings[i], stdout);
+  }
+  return EXIT_SUCCESS;
+}
--- a/libc/src/__support/CMakeLists.txt
+++ b/libc/src/__support/CMakeLists.txt
@ -33,7 +33,6 @@ add_header_library(
  HDRS
    architectures.h
    common.h
-    cpu_features.h
    endian.h
 )

--- a/libc/src/__support/FPUtil/FMA.h
+++ b/libc/src/__support/FPUtil/FMA.h
@ -11,7 +11,6 @@

 #include "src/__support/architectures.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #if defined(LIBC_TARGET_HAS_FMA)

--- a/libc/src/__support/FPUtil/aarch64/FMA.h
+++ b/libc/src/__support/FPUtil/aarch64/FMA.h
@ -10,7 +10,6 @@
 #define LLVM_LIBC_SRC_SUPPORT_FPUTIL_AARCH64_FMA_H

 #include "src/__support/architectures.h"
-#include "src/__support/cpu_features.h"

 #if !defined(LLVM_LIBC_ARCH_AARCH64)
 #error "Invalid include"
--- a/libc/src/__support/FPUtil/multiply_add.h
+++ b/libc/src/__support/FPUtil/multiply_add.h
@ -11,7 +11,6 @@

 #include "src/__support/architectures.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 namespace __llvm_libc {
 namespace fputil {
--- a/libc/src/__support/FPUtil/x86_64/FMA.h
+++ b/libc/src/__support/FPUtil/x86_64/FMA.h
@ -11,7 +11,6 @@

 #include "src/__support/architectures.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #if !defined(LLVM_LIBC_ARCH_X86_64)
 #error "Invalid include"
--- a/libc/src/__support/architectures.h
+++ b/libc/src/__support/architectures.h
@ -49,4 +49,12 @@
 #define LLVM_LIBC_ARCH_ANY_ARM
 #endif

+#if defined(LLVM_LIBC_ARCH_AARCH64)
+#define LIBC_TARGET_HAS_FMA
+#elif defined(LLVM_LIBC_ARCH_X86_64)
+#if (defined(__AVX2__) || defined(__FMA__))
+#define LIBC_TARGET_HAS_FMA
+#endif
+#endif
+
 #endif // LLVM_LIBC_SUPPORT_ARCHITECTURES_H
--- a/libc/src/__support/cpu_features.h
+++ b/libc/src/__support/cpu_features.h
@ -1,43 +0,0 @@
-//===-- Compile time cpu feature detection ----------------------*- C++ -*-===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-// This file lists target cpu features by introspecting compiler enabled
-// preprocessor definitions.
-//===----------------------------------------------------------------------===//
-
-#ifndef LLVM_LIBC_SRC_SUPPORT_CPU_FEATURES_H
-#define LLVM_LIBC_SRC_SUPPORT_CPU_FEATURES_H
-
-#if defined(__SSE2__)
-#define LIBC_TARGET_HAS_SSE2
-#endif
-
-#if defined(__SSE4_2__)
-#define LIBC_TARGET_HAS_SSE4_2
-#endif
-
-#if defined(__AVX__)
-#define LIBC_TARGET_HAS_AVX
-#endif
-
-#if defined(__AVX2__)
-#define LIBC_TARGET_HAS_AVX2
-#endif
-
-#if defined(__AVX512F__)
-#define LIBC_TARGET_HAS_AVX512F
-#endif
-
-#if defined(__AVX512BW__)
-#define LIBC_TARGET_HAS_AVX512BW
-#endif
-
-#if defined(__ARM_FEATURE_FMA) || defined(__AVX2__) || defined(__FMA__)
-#define LIBC_TARGET_HAS_FMA
-#endif
-
-#endif // LLVM_LIBC_SRC_SUPPORT_CPU_FEATURES_H
--- a/libc/src/math/generic/asinf.cpp
+++ b/libc/src/math/generic/asinf.cpp
@ -13,7 +13,6 @@
 #include "src/__support/FPUtil/except_value_utils.h"
 #include "src/__support/FPUtil/multiply_add.h"
 #include "src/__support/FPUtil/sqrt.h"
-#include "src/__support/cpu_features.h"

 #include <errno.h>

--- a/libc/src/math/generic/cosf.cpp
+++ b/libc/src/math/generic/cosf.cpp
@ -14,7 +14,6 @@
 #include "src/__support/FPUtil/except_value_utils.h"
 #include "src/__support/FPUtil/multiply_add.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #include <errno.h>

--- a/libc/src/math/generic/expm1f.cpp
+++ b/libc/src/math/generic/expm1f.cpp
@ -16,7 +16,6 @@
 #include "src/__support/FPUtil/multiply_add.h"
 #include "src/__support/FPUtil/nearest_integer.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #include <errno.h>

--- a/libc/src/math/generic/sincosf.cpp
+++ b/libc/src/math/generic/sincosf.cpp
@ -12,7 +12,6 @@
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/FPUtil/multiply_add.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #include <errno.h>

--- a/libc/src/math/generic/sincosf_utils.h
+++ b/libc/src/math/generic/sincosf_utils.h
@ -12,7 +12,6 @@
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/FPUtil/PolyEval.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #if defined(LIBC_TARGET_HAS_FMA)
 #include "range_reduction_fma.h"
--- a/libc/src/math/generic/sinf.cpp
+++ b/libc/src/math/generic/sinf.cpp
@ -14,7 +14,6 @@
 #include "src/__support/FPUtil/PolyEval.h"
 #include "src/__support/FPUtil/multiply_add.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #include <errno.h>

--- a/libc/src/math/generic/tanf.cpp
+++ b/libc/src/math/generic/tanf.cpp
@ -15,7 +15,6 @@
 #include "src/__support/FPUtil/multiply_add.h"
 #include "src/__support/FPUtil/nearest_integer.h"
 #include "src/__support/common.h"
-#include "src/__support/cpu_features.h"

 #include <errno.h>

--- a/libc/src/math/generic/tanhf.cpp
+++ b/libc/src/math/generic/tanhf.cpp
@ -8,7 +8,6 @@

 #include "src/math/tanhf.h"
 #include "src/__support/FPUtil/FPBits.h"
-#include "src/__support/cpu_features.h"
 #include "src/math/generic/explogxf.h"

 namespace __llvm_libc {
--- a/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
+++ b/utils/bazel/llvm-project-overlay/libc/BUILD.bazel
@ -79,7 +79,6 @@ libc_support_library(
    hdrs = [
        "src/__support/architectures.h",
        "src/__support/common.h",
-        "src/__support/cpu_features.h",
        "src/__support/endian.h",
    ],
 )