[scudo] Overhaul hardware CRC32 feature detection
Summary:
This patch aims at condensing the hardware CRC32 feature detection and making
it slightly more effective on Android.
The following changes are included:
- remove the `CPUFeature` enum, and get rid of one level of nesting of
functions: we only used CRC32, so we just implement and use
`hasHardwareCRC32`;
- allow for a weak `getauxval`: the Android toolchain is compiled at API level
14 for Android ARM, meaning no `getauxval` at compile time, yet we will run
on API level 27+ devices. The `/proc/self/auxv` fallback can work but is
worthless for a process like `init` where the proc filesystem doesn't exist
yet. If a weak `getauxval` doesn't exist, then fallback.
- couple of extra corrections.
Reviewers: alekseyshl
Reviewed By: alekseyshl
Subscribers: kubamracek, aemerson, srhines, kristof.beyls, llvm-commits
Differential Revision: https://reviews.llvm.org/D40322
llvm-svn: 318859
diff --git a/compiler-rt/lib/scudo/scudo_utils.h b/compiler-rt/lib/scudo/scudo_utils.h
index cb7300d..3379819 100644
--- a/compiler-rt/lib/scudo/scudo_utils.h
+++ b/compiler-rt/lib/scudo/scudo_utils.h
@@ -21,7 +21,7 @@
namespace __scudo {
template <class Dest, class Source>
-inline Dest bit_cast(const Source& source) {
+INLINE Dest bit_cast(const Source& source) {
static_assert(sizeof(Dest) == sizeof(Source), "Sizes are not equal!");
Dest dest;
memcpy(&dest, &source, sizeof(dest));
@@ -30,11 +30,7 @@
void NORETURN dieWithMessage(const char *Format, ...);
-enum CPUFeature {
- CRC32CPUFeature = 0,
- MaxCPUFeature,
-};
-bool testCPUFeature(CPUFeature Feature);
+bool hasHardwareCRC32();
INLINE u64 rotl(const u64 X, int K) {
return (X << K) | (X >> (64 - K));