llvm-svn: 45671

ShadowStackCollector, which additionally has reduced overhead with
no sacrifice in portability.

Considering a function @fun with 8 loop-local roots,
ShadowStackCollector introduces the following overhead
(x86):

; shadowstack prologue
        movl    L_llvm_gc_root_chain$non_lazy_ptr, %eax
        movl    (%eax), %ecx
        movl    $___gc_fun, 20(%esp)
        movl    $0, 24(%esp)
        movl    $0, 28(%esp)
        movl    $0, 32(%esp)
        movl    $0, 36(%esp)
        movl    $0, 40(%esp)
        movl    $0, 44(%esp)
        movl    $0, 48(%esp)
        movl    $0, 52(%esp)
        movl    %ecx, 16(%esp)
        leal    16(%esp), %ecx
        movl    %ecx, (%eax)

; shadowstack loop overhead
        (none)

; shadowstack epilogue
        movl    48(%esp), %edx
        movl    %edx, (%ecx)

; shadowstack metadata
        .align  3
___gc_fun:                              # __gc_fun
        .long   8
        .space  4

In comparison to LowerGC:

; lowergc prologue
        movl    L_llvm_gc_root_chain$non_lazy_ptr, %eax
        movl    (%eax), %ecx
        movl    %ecx, 48(%esp)
        movl    $8, 52(%esp)
        movl    $0, 60(%esp)
        movl    $0, 56(%esp)
        movl    $0, 68(%esp)
        movl    $0, 64(%esp)
        movl    $0, 76(%esp)
        movl    $0, 72(%esp)
        movl    $0, 84(%esp)
        movl    $0, 80(%esp)
        movl    $0, 92(%esp)
        movl    $0, 88(%esp)
        movl    $0, 100(%esp)
        movl    $0, 96(%esp)
        movl    $0, 108(%esp)
        movl    $0, 104(%esp)
        movl    $0, 116(%esp)
        movl    $0, 112(%esp)

; lowergc loop overhead
        leal    44(%esp), %eax
        movl    %eax, 56(%esp)
        leal    40(%esp), %eax
        movl    %eax, 64(%esp)
        leal    36(%esp), %eax
        movl    %eax, 72(%esp)
        leal    32(%esp), %eax
        movl    %eax, 80(%esp)
        leal    28(%esp), %eax
        movl    %eax, 88(%esp)
        leal    24(%esp), %eax
        movl    %eax, 96(%esp)
        leal    20(%esp), %eax
        movl    %eax, 104(%esp)
        leal    16(%esp), %eax
        movl    %eax, 112(%esp)

; lowergc epilogue
        movl    48(%esp), %edx
        movl    %edx, (%ecx)

; lowergc metadata
        (none)

llvm-svn: 45670

up to the various compiler pipelines.

This doesn't actually add support for any GC algorithms, which means it 
temporarily breaks a few tests. To be fixed shortly.

llvm-svn: 45669

llvm-svn: 45667

llvm-svn: 45656

llvm-svn: 45655

llvm-svn: 45637

Don't overwrite a variable used by the fallthrough code path in this
case.

llvm-svn: 45630

llvm-svn: 45629

llvm-svn: 45625

llvm-svn: 45624

llvm-svn: 45617

llvm-svn: 45614

llvm-svn: 45608

preserved.

llvm-svn: 45596

llvm-svn: 45574

llvm-svn: 45573

llvm-svn: 45572

llvm-svn: 45571

It is missing validity checks, so it is known broken.  However, it is powerful enough
to compile this contrived code:

void test1(int C, double A, double B, double *P) {
  double Tmp = A*A+B*B;
  *P = C ? Tmp : A;
}

into:

_test1:
	movsd	8(%esp), %xmm0
	cmpl	$0, 4(%esp)
	je	LBB1_2	# entry
LBB1_1:	# entry
	movsd	16(%esp), %xmm1
	mulsd	%xmm1, %xmm1
	mulsd	%xmm0, %xmm0
	addsd	%xmm1, %xmm0
LBB1_2:	# entry
	movl	24(%esp), %eax
	movsd	%xmm0, (%eax)
	ret

instead of:

_test1:
	movsd	16(%esp), %xmm0
	mulsd	%xmm0, %xmm0
	movsd	8(%esp), %xmm1
	movapd	%xmm1, %xmm2
	mulsd	%xmm2, %xmm2
	addsd	%xmm0, %xmm2
	cmpl	$0, 4(%esp)
	je	LBB1_2	# entry
LBB1_1:	# entry
	movapd	%xmm2, %xmm1
LBB1_2:	# entry
	movl	24(%esp), %eax
	movsd	%xmm1, (%eax)
	ret

woo.

llvm-svn: 45570

llvm-svn: 45569

llvm-svn: 45499

llvm-svn: 45496

instruction. Also, use "splice" to move the new instruction instead of
remove/insert (where it was leaking memory anyway).

llvm-svn: 45492

llvm-svn: 45484

Make MachineRegisterInfo::getVRegDef more efficient by aiming the keep the def of the vreg at the start of the list, so the list doesn't need to be traversed.

llvm-svn: 45483

it now returns the machineinstr of the use.  To get the operand, use I.getOperand().

Add a new MachineRegisterInfo::replaceRegWith, which is basically like
Value::replaceAllUsesWith.

llvm-svn: 45482

instruction that defines the specified vreg.  Crazy.

llvm-svn: 45480

operands.  The lists are currently kept in MachineRegisterInfo, but it does
not yet provide an iterator interface to them.

llvm-svn: 45477

a header file from libcodegen.  This violates a layering order: codegen
depends on target, not the other way around.  The fix to this is to 
split TII into two classes, TII and TargetInstrInfoImpl, which defines
stuff that depends on libcodegen.  It is defined in libcodegen, where 
the base is not.

llvm-svn: 45475

values, which means doing extra legalization work.
It would be easier to get this kind of thing right if
there was some documentation...

llvm-svn: 45472

Machine-level API cleanup instigated by Chris.

llvm-svn: 45470

llvm-svn: 45469

llvm-svn: 45468

that "machine" classes are used to represent the current state of
the code being compiled.  Given this expanded name, we can start 
moving other stuff into it.  For now, move the UsedPhysRegs and
LiveIn/LoveOuts vectors from MachineFunction into it.

Update all the clients to match.

This also reduces some needless #includes, such as MachineModuleInfo
from MachineFunction.

llvm-svn: 45467

e.g. MO.isMBB() instead of MO.isMachineBasicBlock().  I don't plan on 
switching everything over, so new clients should just start using the 
shorter names.

Remove old long accessors, switching everything over to use the short
accessor: getMachineBasicBlock() -> getMBB(), 
getConstantPoolIndex() -> getIndex(), setMachineBasicBlock -> setMBB(), etc.

llvm-svn: 45464

  - Eliminate the static "print" method for operands, moving it
    into MachineOperand::print.
  - Change various set* methods for register flags to take a bool
    for the value to set it to.  Remove unset* methods.
  - Group methods more logically by operand flavor in MachineOperand.h

llvm-svn: 45461

  - Add getParent() accessors.
  - Move SubReg out of the AuxInfo union, to make way for future changes.
  - Remove the getImmedValue/setImmedValue methods.
  - in some MachineOperand::Create* methods, stop initializing fields that are dead.

MachineInstr:
  - Delete one copy of the MachineInstr printing code, now there is only one dump
    format and one copy of the code.
  - Make MachineOperand use the parent field to get info about preg register names if
    no target info is otherwise available.
  - Move def/use/kill/dead flag printing to the machineoperand printer, so they are
    always printed for an operand.

llvm-svn: 45460

llvm-svn: 45459

llvm-svn: 45458