stuff isn't used just yet.
We want to model the GCC `-fno-schedule-insns' and `-fno-schedule-insns2'
flags. The hypothesis is that the people who use these flags know what they are
doing, and have hand-optimized the C code to reduce latencies and other
conflicts.
The idea behind our scheme to turn off scheduling is to create a map "on the
side" during DAG generation. It will order the nodes by how they appeared in the
code. This map is then used during scheduling to get the ordering.
llvm-svn: 91392
This change removes the DefaultConstructible
and CopyAssignable constraints on the template
parameter T (the first one).
The second template parameter (R) is defaulted to be
identical to the first and controls the result type.
By specifying it to be (const T&) additionally the
CopyConstructible constraint on T can be removed.
This allows to use StringSwitch e.g. for llvm::Constant
instances.
Regarding the other review feedback regarding performance
because of taking pointers, this class should be completely
optimizable like before, since all methods are inline and
the pointer dereferencing and result value caching should be
possible behind the scenes by the "as-if" rule.
llvm-svn: 91123
- Loosen the restrictions when checking of it branches to a landing pad.
- Make the loop more efficient by checking the '.insert' return value.
- Do cheaper checks first.
llvm-svn: 91101
more than one successor. Normally, these extra successors are dead. However,
some of them may branch to exception handling landing pads. If we remove those
successors, then the landing pads could go away if all predecessors to it are
removed. Before, it was checking if the direct successor was the landing
pad. But it could be the result of jumping through multiple basic blocks to get
to it. If we were to only check for the existence of an EH_LABEL in the basic
block and not remove successors if it's in there, then it could stop actually
dead basic blocks from being removed.
llvm-svn: 91092
The coalescer is supposed to clean these up, but when setting up parameters
for a function call, there may be copies to physregs. If the defining
instruction has been LICM'ed far away, the coalescer won't touch it.
The register allocation hint does not always work - when the register
allocator is backtracking, it clears the hints.
This patch is more conservative than r90502, and does not break
483.xalancbmk/i686. It still breaks the PowerPC bootstrap, so it is disabled
by default, and can be enabled with the -trivial-coalesce-ends option.
llvm-svn: 91049
When a call is placed to spill an interval this spiller will first try to
break the interval up into its component values. Single value intervals and
intervals which have already been split (or are the result of previous splits)
are spilled by the default spiller.
Splitting intervals as described above may improve the performance of generated
code in some circumstances. This work is experimental however, and it still
miscompiles many benchmarks. It's not recommended for general use yet.
llvm-svn: 90951
phi translation of complex expressions like &A[i+1]. This has the
following benefits:
1. The phi translation logic is all contained in its own class with
a strong interface and verification that it is self consistent.
2. The logic is more correct than before. Previously, if intermediate
expressions got PHI translated, we'd miss the update and scan for
the wrong pointers in predecessor blocks. @phi_trans2 is a testcase
for this.
3. We have a lot less code in memdep.
We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).
This patch should fix the miscompiles of 255.vortex, and I tested it
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.
llvm-svn: 90926
The semantics of llvm.dbg.value are that starting from where it is executed, an offset into the specified user source variable is specified to get a new value.
An example:
call void @llvm.dbg.value(metadata !{ i32 7 }, i64 0, metadata !2)
Here the user source variable associated with metadata #2 gets the value "i32 7" at offset 0.
llvm-svn: 90788
