ARM supports clz and ctz directly and both operations have well-defined
results for zero. There is no disadvantage in performance to using the
defined-at-zero versions of llvm.ctlz/cttz intrinsics. We're running into
ARM-specific code written with the assumption that __builtin_clz(0) == 32,
even though that value is technically undefined. The code is failing now
because of llvm optimizations that are taking advantage of the undef
behavior (specifically svn r147255). There's nothing wrong with that
optimization on x86 where any incorrect assumptions about __builtin_clz(0)
will quickly be exposed. For ARM, though, optimizations based on that undef
behavior are likely to cause subtle bugs. Other targets with defined-at-zero
clz/ctz support may want to override the default behavior as well.
llvm-svn: 149086
the gdb testsuite complains too much about the ordering of items printed,
even if the offsets in the debug info are correct.
This reverts commit 027cb30af828f07750f9185782822297a5c57231.
llvm-svn: 149049
"use the new ConstantVector::getSplat method where it makes sense."
Also simplify a bunch of code to use the Builder->getInt32 instead
of doing it the hard and ugly way. Much more progress could be made
here, but I don't plan to do it.
llvm-svn: 148926
address safety analysis (such as e.g. AddressSanitizer or SAFECode) for a specific function.
When building with AddressSanitizer, add AddressSafety function attribute to every generated function
except for those that have __attribute__((no_address_safety_analysis)).
With this patch we will be able to
1. disable AddressSanitizer for a particular function
2. disable AddressSanitizer-hostile optimizations (such as some cases of load widening) when AddressSanitizer is on.
llvm-svn: 148842
- Add atomic-to/from-nonatomic cast types
- Emit atomic operations for arithmetic on atomic types
- Emit non-atomic stores for initialisation of atomic types, but atomic stores and loads for every other store / load
- Add a __atomic_init() intrinsic which does a non-atomic store to an _Atomic() type. This is needed for the corresponding C11 stdatomic.h function.
- Enables the relevant __has_feature() checks. The feature isn't 100% complete yet, but it's done enough that we want people testing it.
Still to do:
- Make the arithmetic operations on atomic types (e.g. Atomic(int) foo = 1; foo++;) use the correct LLVM intrinsic if one exists, not a loop with a cmpxchg.
- Add a signal fence builtin
- Properly set the fenv state in atomic operations on floating point values
- Correctly handle things like _Atomic(_Complex double) which are too large for an atomic cmpxchg on some platforms (this requires working out what 'correctly' means in this context)
- Fix the many remaining corner cases
llvm-svn: 148242
we have a redeclarable type, and only use the new virtual versions
(getPreviousDeclImpl() and getMostRecentDeclImpl()) when we don't have
that type information. This keeps us from penalizing users with strict
type information (and is the moral equivalent of a "final" method).
Plus, settle on the names getPreviousDecl() and getMostRecentDecl()
throughout.
llvm-svn: 148187
APValue::Array and APValue::MemberPointer. All APValue values can now be emitted
as constants.
Add new CGCXXABI entry point for emitting an APValue MemberPointer. The other
entrypoints dealing with constant member pointers are no longer necessary and
will be removed in a later change.
Switch codegen from using EvaluateAsRValue/EvaluateAsLValue to
VarDecl::evaluateValue. This performs caching and deals with the nasty cases in
C++11 where a non-const object's initializer can refer indirectly to
previously-initialized fields within the same object.
Building the intermediate APValue object incurs a measurable performance hit on
pathological testcases with huge initializer lists, so we continue to build IR
directly from the Expr nodes for array and record types outside of C++11.
llvm-svn: 148178
Matt Beaumont-Gay