information.  This allows arbitrary code involving DW_OP_plus_uconst
and DW_OP_deref.  The scheme allows for easy extention to include,
any, or all of the DW_OP_ opcodes.  I thought about just exposing all
of them, but, wasn't sure if people wanted the dwarf opcodes exposed
in the api.  Is that a layering violation?

With this scheme, the entire existing block scheme used by llvm-gcc
can be switched over to the new scheme.  I think that would be
cleaner, as then the compiler specific bits are not present in llvm
proper.  Before the old code can be yanked however, similar code in
clang would have to be removed.

Next up, more testing.

llvm-svn: 83120

llvm-svn: 83103

Remove unnecessary cast.

llvm-svn: 83100

llvm-svn: 83083

so a simple "current register" will suffice. Also add some additional
sanity-checking assertions to make sure things are as we expect.

llvm-svn: 83081

the instruction we're scavenging for. The scavenger needs to know to avoid
them when analyzing register usage.

llvm-svn: 83077

llvm-svn: 83019

llvm-svn: 83016

llvm-svn: 83007

llvm-svn: 82995

physical registers. This is especially critical for the later two since they
start the live interval of a super-register. e.g.
%DO<def> = INSERT_SUBREG %D0<undef>, %S0<kill>, 1
If this instruction is eliminated, the register scavenger will not be happy as
D0 is not defined previously.
This fixes PR5055.

llvm-svn: 82968

llvm-svn: 82909

where FCMP_OEQ is not legal and FCMP_OGE is, such as x86. 

llvm-svn: 82861

allocatable. Even if it doesn't appear to have any defs, it may latter
on after register allocation.

llvm-svn: 82834

llvm-svn: 82825

MathExtras.h in MachineMemOperand.h.

llvm-svn: 82822

llvm-svn: 82821

which have no defs anywhere in the function. In particular, this fixes sinking
of instructions that reference RIP on x86-64, which is currently being modeled
as a register.

llvm-svn: 82815

llvm-svn: 82812

and skipping the defs.

llvm-svn: 82811

llvm-svn: 82803

 - 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.

llvm-svn: 82794

naming scheme used in SelectionDAG, where there are multiple kinds
of "target" nodes, but "machine" nodes are nodes which represent
a MachineInstr.

llvm-svn: 82790

before producing FSIN, FCOS, FSQRT.  If they aren't
so marked we have to assume they might set errno.

llvm-svn: 82781

allows appropriate backends to generate a sqrt instruction.

On x86, this isn't done at -O0 because we go through
FastISel instead.  This is a behavior change from before
this series of sqrt patches started.  I think this is OK
considering that compile speed is most important at -O0, but
could be convinced otherwise.

llvm-svn: 82778

For the AAPCS ABI, SP must always be 4-byte aligned, and at any "public
interface" it must be 8-byte aligned.  For the older ARM APCS ABI, the stack
alignment is just always 4 bytes.  For X86, we currently align SP at
entry to a function (e.g., to 16 bytes for Darwin), but no stack alignment
is needed at other times, such as for a leaf function.

After discussing this with Dan, I decided to go with the approach of adding
a new "TransientStackAlignment" field to TargetFrameInfo.  This value
specifies the stack alignment that must be maintained even in between calls.
It defaults to 1 except for ARM, where it is 4.  (Some other targets may
also want to set this if they have similar stack requirements. It's not
currently required for PPC because it sets targetHandlesStackFrameRounding
and handles the alignment in target-specific code.) The existing StackAlignment
value specifies the alignment upon entry to a function, which is how we've
been using it anyway.

llvm-svn: 82767

Previously, it treated GV+28 GV+0 as different bases, and assumed they could
not alias.

llvm-svn: 82753

llvm-svn: 82742

interest for this, as it currently reserves a register rather than using
the scavenger for matierializing constants as needed.

Instead of scavenging registers on the fly while eliminating frame indices,
new virtual registers are created, and then a scavenged collectively in a
post-pass over the function. This isolates the bits that need to interact
with the scavenger, and sets the stage for more intelligent use, and reuse,
of scavenged registers.

For the time being, this is disabled by default. Once the bugs are worked out,
the current scavenging calls in replaceFrameIndices() will be removed and
the post-pass scavenging will be the default. Until then,
-enable-frame-index-scavenging enables the new code. Currently, only the
Thumb1 back end is set up to use it.

llvm-svn: 82734

delete a few blank lines.

llvm-svn: 82729

llvm-svn: 82727

llvm-svn: 82709

LocalAreaOffset.  (We don't have any of those right now.)
PEI::calculateFrameObjectOffsets includes the absolute value of the
LocalAreaOffset in the cumulative offset value used to calculate the
stack frame size.  It then adds the raw value of the LocalAreaOffset
to the stack size.  For a StackGrowsDown target, that raw value is negative
and has the effect of cancelling out the absolute value that was added
earlier, but that obviously won't work for a StackGrowsUp target.  Change
to subtract the absolute value of the LocalAreaOffset.

llvm-svn: 82693

unconditionally compute MMI even if the target doesn't support EH or Debug info, because the target may use it for other things, this fixes PR5036

llvm-svn: 82684

LiveVariables add implicit kills to correctly track partial register kills. This works well enough and is fairly accurate. But coalescer can make it impossible to maintain these markers. e.g.

        BL <ga:sss1>, %R0<kill,undef>, %S0<kill>, %R0<imp-def>, %R1<imp-def,dead>, %R2<imp-def,dead>, %R3<imp-def,dead>, %R12<imp-def,dead>, %LR<imp-def,dead>, %D0<imp-def>, ...
...
	%reg1031<def> = FLDS <cp#1>, 0, 14, %reg0, Mem:LD4[ConstantPool]
...
   	%S0<def> = FCPYS %reg1031<kill>, 14, %reg0, %D0<imp-use,kill>

When reg1031 and S0 are coalesced, the copy (FCPYS) will be eliminated the the implicit-kill of D0 is lost. In this case it's possible to move the marker to the FLDS. But in many cases, this is not possible. Suppose

	%reg1031<def> = FOO <cp#1>, %D0<imp-def>
...
   	%S0<def> = FCPYS %reg1031<kill>, 14, %reg0, %D0<imp-use,kill>

When FCPYS goes away, the definition of S0 is the "FOO" instruction. However, transferring the D0 implicit-kill to FOO doesn't work since it is the def of D0 itself. We need to fix this in another time by introducing a "kill" pseudo instruction to track liveness.

Disabling the assertion is not ideal, but machine verifier is doing that job now. It's important to know double-def is not a miscomputation since it means a register should be free but it's not tracked as free. It's a performance issue instead.

llvm-svn: 82677

Clean up LiveVariables and change how it deals with partial updates and kills. This also eliminate the horrible check which scan forward to the end of the basic block. It should be faster and more accurate.

llvm-svn: 82676

llvm-svn: 82656

is also the name of their type, as declarations like "EVT EVT" look
really odd.

llvm-svn: 82654

The machine code verifier did not check for explicit operands correctly. It
used MachineInstr::getNumExplicitOperands, but that method may cheat and use
the declared count in the TargetInstrDesc.

Now we check the explicit operands one at a time in visitMachineOperand.

llvm-svn: 82652

llvm-svn: 82641