The Stack slot coloring pass removes a store that is followed by a load
that deal with the same stack slot. The function isLoadFromStackSlot
is supposed to consider the loads that have no side-effects. This
patch fixed the issue by removing the unsafe loads from this function
Eg:
%vreg0<def> = L2_loadruh_io <fi#15>, 0
S2_storeri_io <fi#15>, 0, %vreg0
In this case, we load an unsigned extended half word and store this in to
the same stack slot. The Stack slot coloring pass considers safe to remove
the store. This patch marked all the non-vector byte and half word loads as
unsafe.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286843 91177308-0d34-0410-b5e6-96231b3b80d8
For pairs of 32-bit registers: isub_lo, isub_hi.
For pairs of vector registers: vsub_lo, vsub_hi.
Add generic subreg indices: ps_sub_lo, ps_sub_hi, and a function
HexagonRegisterInfo::getHexagonSubRegIndex(RegClass, GenericSubreg)
that returns the appropriate subreg index for RegClass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@286377 91177308-0d34-0410-b5e6-96231b3b80d8
This is a function to go backwards in a block to find the first
instruction in a bundle, so iterator is a more natural choice for
parameter/return rather than a reference to a MachineInstruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285051 91177308-0d34-0410-b5e6-96231b3b80d8
The main change is to return the code size from
InsertBranch/RemoveBranch.
Patch mostly by Tim Northover
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281505 91177308-0d34-0410-b5e6-96231b3b80d8
Now that MachineBasicBlock::reverse_instr_iterator knows when it's at
the end (since r281168 and r281170), implement
MachineBasicBlock::reverse_iterator directly on top of an
ilist::reverse_iterator by adding an IsReverse template parameter to
MachineInstrBundleIterator. This replaces another hard-to-reason-about
use of std::reverse_iterator on list iterators, matching the changes for
ilist::reverse_iterator from r280032 (see the "out of scope" section at
the end of that commit message). MachineBasicBlock::reverse_iterator
now has a handle to the current node and has obvious invalidation
semantics.
r280032 has a more detailed explanation of how list-style reverse
iterators (invalidated when the pointed-at node is deleted) are
different from vector-style reverse iterators like std::reverse_iterator
(invalidated on every operation). A great motivating example is this
commit's changes to lib/CodeGen/DeadMachineInstructionElim.cpp.
Note: If your out-of-tree backend deletes instructions while iterating
on a MachineBasicBlock::reverse_iterator or converts between
MachineBasicBlock::iterator and MachineBasicBlock::reverse_iterator,
you'll need to update your code in similar ways to r280032. The
following table might help:
[Old] ==> [New]
delete &*RI, RE = end() delete &*RI++
RI->erase(), RE = end() RI++->erase()
reverse_iterator(I) std::prev(I).getReverse()
reverse_iterator(I) ++I.getReverse()
--reverse_iterator(I) I.getReverse()
reverse_iterator(std::next(I)) I.getReverse()
RI.base() std::prev(RI).getReverse()
RI.base() ++RI.getReverse()
--RI.base() RI.getReverse()
std::next(RI).base() RI.getReverse()
(For more details, have a look at r280032.)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281172 91177308-0d34-0410-b5e6-96231b3b80d8
Floating point instructions use general purpose registers, so the few
instructions that can put floating point immediates into registers are,
in fact, integer instruction. Use them explicitly instead of having
pseudo-instructions specifically for dealing with floating point values.
Simplify the constant loading instructions (from sdata) to have only two:
one for 32-bit values and one for 64-bit values: CONST32 and CONST64.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@278244 91177308-0d34-0410-b5e6-96231b3b80d8
Software pipelining is an optimization for improving ILP by
overlapping loop iterations. Swing Modulo Scheduling (SMS) is
an implementation of software pipelining that attempts to
reduce register pressure and generate efficient pipelines with
a low compile-time cost.
This implementaion of SMS is a target-independent back-end pass.
When enabled, the pass should run just prior to the register
allocation pass, while the machine IR is in SSA form. If the pass
is successful, then the original loop is replaced by the optimized
loop. The optimized loop contains one or more prolog blocks, the
pipelined kernel, and one or more epilog blocks.
This pass is enabled for Hexagon only. To enable for other targets,
a couple of target specific hooks must be implemented, and the
pass needs to be called from the target's TargetMachine
implementation.
Differential Review: http://reviews.llvm.org/D16829
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277169 91177308-0d34-0410-b5e6-96231b3b80d8
The post register allocator scheduler can generate poor schedules
because the scoreboard hazard recognizer is unable to identify
hazards for Hexagon precisely. Instead, Hexagon should use a DFA
based hazard recognizer.
Patch by Brendon Cahoon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277143 91177308-0d34-0410-b5e6-96231b3b80d8
The Hexagon schedulers need to handle instructions with a latency
of 0 or 2 more accurately. The problem, in v60, is that a dependence
between two instructions with a 2 cycle latency can use a .cur version
of the source to achieve a 0 cycle latency when the use is in the
same packet. Any othe use, must be at least 2 packets later, or a
stall occurs. In other words, the compiler does not want to schedule
the dependent instructions 1 cycle later.
To achieve this, the latency adjustment code allows only a single
dependence to have a zero latency. All other instructions have the
other value, which is typically 2 cycles. We use a heuristic to
determine which instruction gets the 0 latency.
The Hexagon machine scheduler was also changed to increase the cost
associated with 0 latency dependences than can be scheduled in the
same packet.
Patch by Brendon Cahoon.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275625 91177308-0d34-0410-b5e6-96231b3b80d8
- Treat bitwise OR with a frame index as an ADD wherever possible, fold it
into addressing mode.
- Extend patterns for memops to allow memops with frame indexes as address
operands.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275569 91177308-0d34-0410-b5e6-96231b3b80d8
On Hexagon is it legal to packetize the instructions setting up call
arguments with the call instruction itself. This was already done,
except for tail calls. Make sure tail calls are handled as well.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@275458 91177308-0d34-0410-b5e6-96231b3b80d8
Stop using an implicit conversion from the return of
MachineBasicBlock::getFirstTerminator to MachineInstr*. In two cases,
directly dereference to a MachineInstr& since later code assumes it's
valid. In a third case, change to an iterator since later code checks
against MachineBasicBlock::end.
Although the fix for the third case avoids undefined behaviour, I expect
this doesn't cause a functionality change in practice (since the basic
block already has a terminator).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274898 91177308-0d34-0410-b5e6-96231b3b80d8
This is mostly a mechanical change to make TargetInstrInfo API take
MachineInstr& (instead of MachineInstr* or MachineBasicBlock::iterator)
when the argument is expected to be a valid MachineInstr. This is a
general API improvement.
Although it would be possible to do this one function at a time, that
would demand a quadratic amount of churn since many of these functions
call each other. Instead I've done everything as a block and just
updated what was necessary.
This is mostly mechanical fixes: adding and removing `*` and `&`
operators. The only non-mechanical change is to split
ARMBaseInstrInfo::getOperandLatencyImpl out from
ARMBaseInstrInfo::getOperandLatency. Previously, the latter took a
`MachineInstr*` which it updated to the instruction bundle leader; now,
the latter calls the former either with the same `MachineInstr&` or the
bundle leader.
As a side effect, this removes a bunch of MachineInstr* to
MachineBasicBlock::iterator implicit conversions, a necessary step
toward fixing PR26753.
Note: I updated WebAssembly, Lanai, and AVR (despite being
off-by-default) since it turned out to be easy. I couldn't run tests
for AVR since llc doesn't link with it turned on.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@274189 91177308-0d34-0410-b5e6-96231b3b80d8
This used to be free, copying and moving DebugLocs became expensive
after the metadata rewrite. Passing by reference eliminates a ton of
track/untrack operations. No functionality change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@272512 91177308-0d34-0410-b5e6-96231b3b80d8
