When tail merging it may be necessary to remove MMOs from memory operations to
ensures later passes (e.g., MI sched) conservatively compute dependencies.
Currently, we only remove the MMO from the common tail if the MMO doesn't match
with the relative instruction in the non-common tail(s).
A more robust solution would be to add multiple MMOs from the duplicate MIs to
the new MI. Currently ScheduleDAGInstrs.cpp ignores all MMOs on instructions
with multiple MMOs, so this solution is equivalent for the time being.
No test case included as this is incredibly difficult to reproduce.
Patch was a collaborative effort between Ana Pazos and myself.
Phabricator: http://reviews.llvm.org/D7769
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@231799 91177308-0d34-0410-b5e6-96231b3b80d8
In order to enable the preservation of noalias function parameter information
after inlining, and the representation of block-level __restrict__ pointer
information (etc.), additional kinds of aliasing metadata will be introduced.
This metadata needs to be carried around in AliasAnalysis::Location objects
(and MMOs at the SDAG level), and so we need to generalize the current scheme
(which is hard-coded to just one TBAA MDNode*).
This commit introduces only the necessary refactoring to allow for the
introduction of other aliasing metadata types, but does not actually introduce
any (that will come in a follow-up commit). What it does introduce is a new
AAMDNodes structure to hold all of the aliasing metadata nodes associated with
a particular memory-accessing instruction, and uses that structure instead of
the raw MDNode* in AliasAnalysis::Location, etc.
No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@213859 91177308-0d34-0410-b5e6-96231b3b80d8
This seems to me an obvious place to allow target passes to annotate
memory operations. There are plenty of bits, and I'm not aware of
another good way for early target passes to propagate hints along to
later passes. Target independent transforms can simply preserve them,
the way they preserve the other flags. Like MachineMemOperands in
general, if the target flags are lost we must still generate correct
code.
This has lots of uses, but I want this flexibility now to make it
easier to work with the new MachineTraceMetrics
analysis. MachineTraceMetrics can gather a lot of information about
instructions based on the surrounding code. This information can be
used to influence postRA machine passes that don't work on SSA form.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180666 91177308-0d34-0410-b5e6-96231b3b80d8
This means the same as LoadInst/StoreInst::isUnordered(), and implies
!isVolatile().
Atomic loads and stored are also ordered, and this is the right method
to check if it is safe to reorder memory operations. Ordered atomics
can't be reordered wrt normal loads and stores, which is a stronger
constraint than volatile.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162859 91177308-0d34-0410-b5e6-96231b3b80d8
This is the CodeGen equivalent of r153747. I tested that there is not noticeable
performance difference with any combination of -O0/-O2 /-g when compiling
gcc as a single compilation unit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153817 91177308-0d34-0410-b5e6-96231b3b80d8
When this field is true it means that the load is from constant (runt-time or compile-time) and so can be hoisted from loops or moved around other memory accesses
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144100 91177308-0d34-0410-b5e6-96231b3b80d8
"getFixedStack" on the MachinePointerInfo class. While
this isn't the problem I'm setting out to solve, it is the
right way to eliminate PseudoSourceValue, so lets go with it.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114406 91177308-0d34-0410-b5e6-96231b3b80d8
MachinePointerInfo, propagating the type out a level of API. Remove
the old MachineFunction::getMachineMemOperand impl.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114393 91177308-0d34-0410-b5e6-96231b3b80d8
MachinePointerInfo struct, no functionality change.
This also adds an assert to MachineMemOperand::MachineMemOperand
that verifies that the Value* is either null or is an IR pointer type.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114389 91177308-0d34-0410-b5e6-96231b3b80d8
- Allocate MachineMemOperands and MachineMemOperand lists in MachineFunctions.
This eliminates MachineInstr's std::list member and allows the data to be
created by isel and live for the remainder of codegen, avoiding a lot of
copying and unnecessary translation. This also shrinks MemSDNode.
- Delete MemOperandSDNode. Introduce MachineSDNode which has dedicated
fields for MachineMemOperands.
- Change MemSDNode to have a MachineMemOperand member instead of its own
fields with the same information. This introduces some redundancy, but
it's more consistent with what MachineInstr will eventually want.
- Ignore alignment when searching for redundant loads for CSE, but remember
the greatest alignment.
Target-specific code which previously used MemOperandSDNodes with generic
SDNodes now use MemIntrinsicSDNodes, with opcodes in a designated range
so that the SelectionDAG framework knows that MachineMemOperand information
is available.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82794 91177308-0d34-0410-b5e6-96231b3b80d8
two different places for printing MachineMemOperands.
Drop the virtual from Value::dump and instead give Value a
protected virtual hook that can be overridden by subclasses
to implement custom printing. This lets printing be more
consistent, and simplifies printing of PseudoSourceValue
values.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82599 91177308-0d34-0410-b5e6-96231b3b80d8
the base pointer, without the offset. This matches MemSDNode's
new alignment behavior, and holds more interesting information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82473 91177308-0d34-0410-b5e6-96231b3b80d8
alignment and volatility information, such as loads and
stores, to reduce the number of integer values added to
the FoldingSetNodeID.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55058 91177308-0d34-0410-b5e6-96231b3b80d8
