A target index operand looks a lot like a constant pool reference, but
it is completely target-defined. It contains the 8-bit TargetFlags, a
32-bit index, and a 64-bit offset. It is preserved by all code generator
passes.
TargetIndex operands can be used to carry target-specific information in
cases where immediate operands won't suffice.
llvm-svn: 161441
Warns on anti-patterns/typos in the 'size' argument to strncat. The
correct size argument should look like the following:
- strncat(dst, src, sizeof(dst) - strlen(dest) - 1);
We warn on:
- sizeof(dst)
- sizeof(src)
- sizeof(dst) - strlen(dst)
- sizeof(src) - anything
(This has been implemented in void Sema::CheckStrncatArguments().)
llvm-svn: 161440
Compare the critical paths of the two traces through an if-conversion
candidate. If the difference is larger than the branch brediction
penalty, reject the if-conversion. If would never pay.
llvm-svn: 161433
The implementation also includes a Relax NG schema and tests for the schema
itself. The schema is used in c-index-test to verify that XML documents we
produce are valid. In order to do the validation, we add an optional libxml2
dependency for c-index-test.
Credits for CMake part go to Doug Gregor. Credits for Autoconf part go to Eric
Christopher. Thanks!
llvm-svn: 161431
a use or a BB, but it is inline in the handling of the invoke instruction.
This patch refactors it so that it can be used in other cases. For example, in
define i32 @f(i32 %x) {
bb0:
%cmp = icmp eq i32 %x, 0
br i1 %cmp, label %bb2, label %bb1
bb1:
br label %bb2
bb2:
%cond = phi i32 [ %x, %bb0 ], [ 0, %bb1 ]
%foo = add i32 %cond, %x
ret i32 %foo
}
GVN should be able to replace %x with 0 in any use that is dominated by the
true edge out of bb0. In the above example the only such use is the one in
the phi.
llvm-svn: 161429
and "instruction address -> file/line" lookup.
Instead of plain collection of rows, debug line table for compilation unit is now
treated as the number of row ranges, describing sequences (series of contiguous machine
instructions). The sequences are not always listed in the order of increasing
address, so previously used std::lower_bound() sometimes produced wrong results.
Now the instruction address lookup consists of two stages: finding the correct
sequence, and searching for address in range of rows for this sequence.
llvm-svn: 161414
We give a bonus for every argument because the argument setup is not needed
anymore when the function is inlined. With this patch we interpret byval
arguments as a compact representation of many arguments. The byval argument
setup is implemented in the backend as an inline memcpy, so to model the
cost as accurately as possible we take the number of pointer-sized elements
in the byval argument and give a bonus of 2 instructions for every one of
those. The bonus is capped at 8 elements, which is the number of stores
at which the x86 backend switches from an expanded inline memcpy to a real
memcpy. It would be better to use the real memcpy threshold from the backend,
but it's not available via TargetData.
This change brings the performance of c-ray in line with gcc 4.7. The included
test case tries to reproduce the c-ray problem to catch regressions for this
benchmark early, its performance is dominated by the inline decision of a
specific call.
This only has a small impact on most code, more on x86 and arm than on x86_64
due to the way the ABI works. When building LLVM for x86 it gives a small
inline cost boost to virtually any function using StringRef or STL allocators,
but only a 0.01% increase in overall binary size. The size of gcc compiled by
clang actually shrunk by a couple bytes with this patch applied, but not
significantly.
llvm-svn: 161413
instsimplify+inline strategy.
The crux of the problem is that instsimplify was reasonably relying on
an invariant that is true within any single function, but is no longer
true mid-inline the way we use it. This invariant is that an argument
pointer != a local (alloca) pointer.
The fix is really light weight though, and allows instsimplify to be
resiliant to these situations: when checking the relation ships to
function arguments, ensure that the argumets come from the same
function. If they come from different functions, then none of these
assumptions hold. All credit to Benjamin Kramer for coming up with this
clever solution to the problem.
llvm-svn: 161410
Previously, MBP essentially aligned every branch target it could. This
bloats code quite a bit, especially non-looping code which has no real
reason to prefer aligned branch targets so heavily.
As Andy said in review, it's still a bit odd to do this without a real
cost model, but this at least has much more plausible heuristics.
Fixes PR13265.
llvm-svn: 161409
This is useful for example for %n in printf, which expects
a pointer to int with the same logic for checking as %d
would have in scanf.
llvm-svn: 161407
if checked out under clang/tools/extra.
This is mostly so folks other than me can start to test. Documentation,
details, and an announcement are still in the works.
llvm-svn: 161405
With this we can build and test the remove-cstr-calls tool which should
serve as a good example of how to add tools and their tests to the
repository.
llvm-svn: 161404
If the result of a common subexpression is used at all uses of the candidate
expression, CSE should not increase the live range of the common subexpression.
rdar://11393714 and rdar://11819721
llvm-svn: 161396
update implementation to match. An elidable, non-trivial constructor call is a
side-effect under this definition, but wasn't under the old one, because we are
not required to evaluate it even though it may have an effect.
Also rationalize checking for volatile reads: just look for lvalue-to-rvalue
conversions on volatile glvalues, and ignore whether a DeclRefExpr etc is for
a volatile variable.
llvm-svn: 161393
included in warning groups. Warning groups can only contain warnings, because only
warnings can be mapped to errors or ignored.
This caught a few diagnostics that were incorrectly in diagnostic groups, and
could have resulted in a compiler crash when those diagnostic groups were mapped.
Fixes <rdar://problem/12044436>
llvm-svn: 161389
was mistakenly classifying dynamic_casts which might throw as having no side
effects.
Switch it from a visitor to a switch, so it is kept up-to-date as future Expr
nodes are added. Move it from ExprConstant.cpp to Expr.cpp, since it's not
really related to constant expression evaluation.
Since we use HasSideEffect to determine whether to emit an unused global with
internal linkage, this has the effect of suppressing emission of globals in
some cases.
I've left many of the Objective-C cases conservatively assuming that the
expression has side-effects. I'll leave it to someone with better knowledge
of Objective-C than mine to improve them.
llvm-svn: 161388
require an AddressClass, which is useless at this
point since it already knows the distinction between
32-bit Thumb opcodes and 32-bit ARM opcodes.
llvm-svn: 161382
Ted Kremenek