llvm-svn: 141594

Allow targets to expand COPY and other standard pseudo-instructions
before they are expanded with copyPhysReg().

This allows the target to examine the COPY instruction for extra
operands indicating it can be widened to a preferable super-register
copy.  See the ARM -widen-vmovs option.

llvm-svn: 141578

llvm-svn: 141576

For example, MachineLICM should not hoist a load that is not guaranteed to be executed.
Radar 10254254.

llvm-svn: 141569

across unwind edges. This is for the back-end which expects such things.

The code is from the original SjLj EH pass.

llvm-svn: 141463

do. This will be useful later on with the new SJLJ stuff.

llvm-svn: 141416

Fixes <rdar://problem/10235725>

llvm-svn: 141357

llvm-svn: 141356

llvm-svn: 141333

site.

llvm-svn: 141226

to the landing pad. This will be used by the back-end to generate the jump
tables for dispatching the arriving longjmp in sjlj eh.

llvm-svn: 141224

llvm-svn: 141221

PhysReg operands are not allowed to have sub-register indices at all.

For virtual registers with sub-reg indices, check that all registers in
the register class support the sub-reg index.

llvm-svn: 141220

llvm-svn: 141218

llvm-svn: 141214

EXTRACT_SUBREG is emitted as %dst = COPY %src:sub, so there is no need to
constrain the %dst register class.  RegisterCoalescer will apply the
necessary constraints if it decides to eliminate the COPY.

The %src register class does need to be constrained to something with
the right sub-registers, though.  This is currently done manually with
COPY_TO_REGCLASS nodes.  They can possibly be removed after this patch.

llvm-svn: 141207

The register class created by INSERT_SUBREG and SUBREG_TO_REG must be
legal and support the SubIdx sub-registers.

The new getSubClassWithSubReg() hook can compute that.

This may create INSERT_SUBREG instructions defining a larger register
class than the sub-register being inserted.  That is OK,
RegisterCoalescer will constrain the register class as needed when it
eliminates the INSERT_SUBREG instructions.

llvm-svn: 141198

TwoAddressInstructionPass should annotate instructions with <undef>
flags when it lower REG_SEQUENCE instructions.  LiveIntervals should not
be in the business of modifying code (except for kill flags, perhaps).

llvm-svn: 141187

For example:

  %vreg10:dsub_0<def,undef> = COPY %vreg1
  %vreg10:dsub_1<def> = COPY %vreg2

is rewritten as:

  %D2<def> = COPY %D0, %Q1<imp-def>
  %D3<def> = COPY %D1, %Q1<imp-use,kill>, %Q1<imp-def>

The first COPY doesn't care about the previous value of %Q1, so it
doesn't read that register.

The second COPY is a partial redefinition of %Q1, so it implicitly kills
and redefines that register.

This makes it possible to recognize instructions that can harmlessly
clobber the full super-register.  The write and don't read the
super-register.

llvm-svn: 141139

RegisterCoalescer can create sub-register defs when it is joining a
register with a sub-register.  Add <undef> flags to these new
sub-register defs where appropriate.

llvm-svn: 141138

Teach the MC to output code/data region marker labels in MachO and ELF modes.  These are used by disassemblers to provide better disassembly, particularly on targets like ARM Thumb that like to intermingle data in the TEXT segment.

llvm-svn: 141135

llvm-svn: 141125

The <undef> flag says that a MachineOperand doesn't read its register,
or doesn't depend on the previous value of its register.

A full register def never depends on the previous register value.  A
partial register def may depend on the previous value if it is intended
to update part of a register.

For example:

  %vreg10:dsub_0<def,undef> = COPY %vreg1
  %vreg10:dsub_1<def> = COPY %vreg2

The first copy instruction defines the full %vreg10 register with the
bits not covered by dsub_0 defined as <undef>.  It is not considered a
read of %vreg10.

The second copy modifies part of %vreg10 while preserving the rest.  It
has an implicit read of %vreg10.

This patch adds a MachineOperand::readsReg() method to determine if an
operand reads its register.

Previously, this was modelled by adding a full-register <imp-def>
operand to the instruction.  This approach makes it possible to
determine directly from a MachineOperand if it reads its register.  No
scanning of MI operands is required.

llvm-svn: 141124

llvm-svn: 141050

llvm-svn: 141040

Move the grabbing of the jump buffer into the caller function, eliminating the need for returning a std::pair.

llvm-svn: 141026

llvm-svn: 141005

llvm-svn: 141004

Moved type construction out of the loop and added an assert on the legality of the type. Formatted lines to the 80 char limit.

llvm-svn: 140952

and the alignment is 0 (i.e., it's defined globally in one file and declared in
another file) it could get an alignment which is larger than the ABI allows for
that type, resulting in aligned moves being used for unaligned loads.

For instance, in file A.c:

   struct S s;

In file B.c:
   struct {
     // something long
   };
   extern S s;

   void foo() {
     struct S p = s;
     // ...
   }

this copy is a 'memcpy' which is turned into a series of 'movaps' instructions
on X86. But this is wrong, because 'struct S' has alignment of 4, not 16.

llvm-svn: 140902

llvm-svn: 140899

It will soon need the context.

llvm-svn: 140896

thanks to Duncan.

llvm-svn: 140850

This helps with porting code from 2.9 to 3.0 as TargetSelect.h changed location,
and if you include the old one by accident you will trigger this assert.

llvm-svn: 140848

Clean up uses of switch instructions so they are not dependent on the operand ordering.  Patch by Stepan Dyatkovskiy.

llvm-svn: 140803

llvm-svn: 140784

llvm-svn: 140767

llvm-svn: 140745

The function needs to scan the implicit operands anyway, so no
performance is won by caching the number of implicit operands added to
an instruction.

This also fixes a bug when adding operands after an implicit operand has
been added manually.  The NumImplicitOps count wasn't kept up to date.

MachineInstr::addOperand() will now consistently place all explicit
operands before all the implicit operands, regardless of the order they
are added.  It is possible to change an MI opcode and add additional
explicit operands.  They will be inserted before any existing implicit
operands.

The only exception is inline asm instructions where operands are never
reordered.  This is because of a hack that marks explicit clobber regs
on inline asm as <implicit-def> to please the fast register allocator.
This hack can go away when InstrEmitter and FastIsel can add exact
<dead> flags to physreg defs.

llvm-svn: 140744

Upon further review, most of the EH code should remain written at the IR
level. The part which breaks SSA form is the dispatch table, so that part will
be moved to the back-end.

llvm-svn: 140730