summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDavid Kalnischkies <david@kalnischkies.de>2020-05-21 22:17:42 +0200
committerDavid Kalnischkies <david@kalnischkies.de>2020-05-25 12:05:00 +0200
commit574249cd721a3cdbb79b6e457384a55827856b6a (patch)
treeb6c98b9f776aee10b019b3b2211e9c1625ec6025
parentc3bfdbfa3ae868515a67142d2df6200a3cb34d35 (diff)
Allow FMV SSE4.2 detection to succeed on clang
As the builtins were used in the feature test also in the default branch clang fails to compile the test helpfully complaining that you need to compile with sse4.2 to use that while on gcc it is optimized out as unused code and produces only a warning for that… removing the code from the default branch fixes this problem, but we adapt the code some more to avoid compilers optimizing it out in the future just in case.
-rw-r--r--CMake/CheckCxxTarget.cmake7
-rw-r--r--CMakeLists.txt4
-rw-r--r--apt-pkg/pkgcache.cc3
3 files changed, 6 insertions, 8 deletions
diff --git a/CMake/CheckCxxTarget.cmake b/CMake/CheckCxxTarget.cmake
index 373c0be4c..17c32bfac 100644
--- a/CMake/CheckCxxTarget.cmake
+++ b/CMake/CheckCxxTarget.cmake
@@ -25,11 +25,12 @@
# SOFTWARE.
+include(CheckCXXSourceCompiles)
function(check_cxx_target var target code)
check_cxx_source_compiles(
"
- __attribute__((target(\"${target}\"))) static int foo() { ${code} return 1; }
- __attribute__((target(\"default\"))) static int foo() { ${code} return 0; }
- int main() { return foo(); }
+ __attribute__((target(\"${target}\"))) static int foo(int i) { return ${code}; }
+ __attribute__((target(\"default\"))) static int foo(int i) { return i; }
+ int main(int i, char **) { return foo(i); }
" ${var})
endfunction()
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 9df96ee85..115041f54 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -198,8 +198,8 @@ endif()
# Check multiversioning
include(CheckCxxTarget)
-check_cxx_target(HAVE_FMV_SSE42_AND_CRC32 "sse4.2" "__builtin_ia32_crc32si(0, 1llu);")
-check_cxx_target(HAVE_FMV_SSE42_AND_CRC32DI "sse4.2" "__builtin_ia32_crc32di(0, 1llu);")
+check_cxx_target(HAVE_FMV_SSE42_AND_CRC32 "sse4.2" "__builtin_ia32_crc32si(0,i)|__builtin_ia32_crc32hi(0,i)|__builtin_ia32_crc32qi(0,i)")
+check_cxx_target(HAVE_FMV_SSE42_AND_CRC32DI "sse4.2" "__builtin_ia32_crc32di(0,i)")
# Configure some variables like package, version and architecture.
set(PACKAGE ${PROJECT_NAME})
diff --git a/apt-pkg/pkgcache.cc b/apt-pkg/pkgcache.cc
index 02448a073..7eb5ab10b 100644
--- a/apt-pkg/pkgcache.cc
+++ b/apt-pkg/pkgcache.cc
@@ -214,8 +214,6 @@ map_id_t pkgCache::sHash(StringView Str) const
return Hash % HeaderP->GetHashTableSize();
}
-#if defined(HAVE_FMV_SSE42_AND_CRC32)
-
#ifdef HAVE_FMV_SSE42_AND_CRC32
__attribute__((target("sse4.2"))) static uint32_t hash32(uint32_t crc32, const unsigned char *input, size_t size)
{
@@ -253,7 +251,6 @@ __attribute__((target("sse4.2"))) static uint32_t hash32(uint32_t crc32, const u
crc32 ^= 0xffffffffU;
return crc32;
}
-#endif
__attribute__((target("default")))
#endif