* Most of the transforms come through intact by having each transformed load or
store copy the ordering and synchronization scope of the original.
* The transform that turns a global only accessed in main() into an alloca
(since main is non-recursive) with a store of the initial value uses an
unordered store, since it's guaranteed to be the first thing to happen in main.
(Threads may have started before main (!) but they can't have the address of a
function local before the point in the entry block we insert our code.)
* The heap-SRoA transforms are disabled in the face of atomic operations. This
can probably be improved; it seems odd to have atomic accesses to an alloca
that doesn't have its address taken.
AnalyzeGlobal keeps track of the strongest ordering found in any use of the
global. This is more information than we need right now, but it's cheap to
compute and likely to be useful.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149847 91177308-0d34-0410-b5e6-96231b3b80d8
logic by half: isOnlyReachableViaThisEdge was trying to be clever and
handle the case of a branch to a basic block which is contained in a
loop. This costs a domtree lookup and is completely useless due to
GVN's position in the pass pipeline: all loops have preheaders at this
point, which means it is enough for isOnlyReachableViaThisEdge to check
that Dst has only one predecessor. (I checked this theoretical argument
by running over the entire nightly testsuite, and indeed it is so!).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149838 91177308-0d34-0410-b5e6-96231b3b80d8
convert at least one client over to use them. Subsequent patches both to
LLVM and Clang will try to convert more people over to a common set of
predicates.
This round of predicates is focused on OS-categorization predicates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149815 91177308-0d34-0410-b5e6-96231b3b80d8
ConstantDataArray::getString direction, instead of "boxing" each
byte into a ConstantInt and using ConstantArray::get.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149805 91177308-0d34-0410-b5e6-96231b3b80d8
but with a critical fix to the SelectionDAG code that optimizes copies
from strings into immediate stores: the previous code was stopping reading
string data at the first nul. Address this by adding a new argument to
llvm::getConstantStringInfo, preserving the behavior before the patch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149800 91177308-0d34-0410-b5e6-96231b3b80d8
cache disassemblers according to the string value
of the target triple, not according to the enum
of the triple CPU. The reason for this is that
certain attributes of the instruction set are not
reflected in the enum, but only in the string.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149773 91177308-0d34-0410-b5e6-96231b3b80d8
A live range that has an early clobber tied redef now looks like a
normal tied redef, except the early clobber def uses the early clobber
slot.
This is enough to handle any strange interference problems.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149769 91177308-0d34-0410-b5e6-96231b3b80d8
I don't have a test that fails because of this, but a test case like
CodeGen/X86/2009-12-01-EarlyClobberBug.ll exposes the problem. EAX is
redefined by a tied early clobber operand on inline asm, and the live
range should look like this:
%EAX,inf = [48r,64e:0)[64e,80r:1) 0@48r 1@64e
Previously, the two values got merged:
%EAX,inf = [48r,80r:0) 0@48r
With this bug fixed, the REDEF_BY_EC VNInfo flag is no longer needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149768 91177308-0d34-0410-b5e6-96231b3b80d8
Andy, in a previous commit you made this into an ImmutablePass so that you could
add it to the PassManager, then in the next commit you left it a Pass but
removed the code that added it to the PM. If you do add it to the PM then the PM
should take care of deleting it, but it's also true that nothing in codegen
needs this object to exist after it's done its work here. It's not clear to me
which design you want; this should likely either cease to be a Pass or be added
to the PM where other parts of CodeGen will request it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149765 91177308-0d34-0410-b5e6-96231b3b80d8
If a value is defined by a COPY, that instuction can easily and cheaply
be found by getInstructionFromIndex(VNI->def).
This reduces the size of VNInfo from 24 to 16 bytes, and improves
llc compile time by 3%.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149763 91177308-0d34-0410-b5e6-96231b3b80d8
