Before register allocation, instructions can be moved across calls in
order to reduce register pressure. After register allocation, we don't
gain a lot by moving callee-saved defs across calls. In fact, since the
scheduler doesn't have a good idea how registers are used in the callee,
it can't really make good scheduling decisions.
This changes the schedule in two ways: 1. Latencies to call uses and
defs are no longer accounted for, causing some random shuffling around
calls. This isn't really a problem since those uses and defs are
inaccurate proxies for what happens inside the callee. They don't
represent registers used by the call instruction itself.
2. Instructions are no longer moved across calls. This didn't happen
very often, and the scheduling decision was made on dubious information
anyway.
As with any scheduling change, benchmark numbers shift around a bit,
but there is no positive or negative trend from this change.
This makes the post-ra scheduler 5% faster for ARM targets.
The secret motivation for this patch is the introduction of register
mask operands representing call clobbers. The most efficient way of
handling regmasks in ScheduleDAGInstrs is to model them as barriers for
physreg live ranges, but not for virtreg live ranges. That's fine
pre-ra, but post-ra it would have the same effect as this patch.
llvm-svn: 151265
it with memcpy. This also fixes a problem on big-endian hosts, where
addUnaligned would return different results depending on the alignment
of the data.
llvm-svn: 151247
* Handle some situations where we should never make a decl more visible,
even when merging in an explicit visibility.
* Handle attributes in members of classes that are explicitly specialized.
Thanks Nico for the report and testing, Eric for the initial review, and dgregor
for the awesome test27 :-)
llvm-svn: 151236
C++11, and with braced-init-list initializers in conditions. This exposed an
ambiguity with enum underlying types versus bitfields, which we resolve by
treating 'enum E : T {' as always defining an enumeration (even if it would
only successfully parse as a bitfield). This appears to be g++ compatible.
llvm-svn: 151227
value is zero. Instead of a cmov + op, issue an conditional op instead. e.g.
cmp r9, r4
mov r4, #0
moveq r4, #1
orr lr, lr, r4
should be:
cmp r9, r4
orreq lr, lr, #1
That is, optimize (or x, (cmov 0, y, cond)) to (or.cond x, y). Similarly extend
this to xor as well as (and x, (cmov -1, y, cond)) => (and.cond x, y).
It's possible to extend this to ADD and SUB but I don't think they are common.
rdar://8659097
llvm-svn: 151224
Make this call an exception in ExprEngine::invalidateArguments:
'int pthread_setspecific(ptheread_key k, const void *)' stores
a value into thread local storage. The value can later be retrieved
with 'void *ptheread_getspecific(pthread_key)'. So even thought the
parameter is 'const void *', the region escapes through the
call.
(Here we just blacklist the call in the ExprEngine's default
logic. Another option would be to add a checker which evaluates
the call and triggers the call to invalidate regions.)
Teach the Malloc Checker, which treats all system calls as safe about
the API.
llvm-svn: 151220
Objective-C classes. This allows LLDB to find
ivars declared in class extensions in modules other
than where the debugger is currently stopped (we
already supported this when the debugger was
stopped in the same module as the definition).
This involved the following main changes:
- The ObjCLanguageRuntime now knows how to hunt
for the authoritative version of an Objective-C
type. It looks for the symbol indicating a
definition, and then gets the type from the
module containing that symbol.
- ValueObjects now report their type with a
potential override, and the override is set if
the type of the ValueObject is an Objective-C
class or pointer type that is defined somewhere
other than the original reported type. This
means that "frame variable" will always use the
complete type if one is available.
- The ClangASTSource now looks for the complete
type when looking for ivars. This means that
"expr" will always use the complete type if one
is available.
- I added a testcase that verifies that both
"frame variable" and "expr" work.
llvm-svn: 151214
Brendon Cahoon