It can happen that a live debug variable is the last use of a sub-register, and
the register allocator will pick a larger register class for the virtual
register.  If the allocated register doesn't support the sub-register index,
just use %noreg for the debug variables instead of asserting.

In PR9872, a debug variable ends up in the sub_8bit_hi part of a GR32_ABCD
register. The register is split and one part is inflated to GR32 and assigned
%ESI because there are no more normal uses of sub_8bit_hi.

Since %ESI doesn't have that sub-register, substPhysReg asserted. Now it will
simply insert a %noreg instead, and the debug variable will be marked
unavailable in that range.

We don't currently have a way of saying: !"value" is in bits 8-15 of %ESI, I
don't know if DWARF even supports that.

llvm-svn: 131073

llvm-svn: 130562

There can be multiple defs for a single virtual register when they are defining
sub-registers.

The missing <dead> flag was stopping the inline spiller from eliminating dead
code after rematerialization.

llvm-svn: 128888

llvm-svn: 127098

These functions not longer assert when passed 0, but simply return false instead.

No functional change intended.

llvm-svn: 123155

Print virtual registers numbered from 0 instead of the arbitrary
FirstVirtualRegister. The first virtual register is printed as %vreg0.
TRI::NoRegister is printed as %noreg.

llvm-svn: 123107

Instead encode llvm IR level property "HasSideEffects" in an operand (shared
with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check
the operand when the instruction is an INLINEASM.

This allows memory instructions to be moved around INLINEASM instructions.

llvm-svn: 123044

llvm-svn: 123031

llvm-svn: 117155

llvm-svn: 116890

Pull an unsigned out of the Contents union such that it has the same size as two
pointers and no padding.

Arrange members such that the Contents union and all pointers can be 8-byte
aligned without padding.

This speeds up code generation by 0.8% on a 64-bit host. 32-bit hosts should be
unaffected.

llvm-svn: 116857

llvm-svn: 114463

llvm-svn: 114409

"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.

llvm-svn: 114406

llvm-svn: 114400

to the MachineFunction construction methods.

llvm-svn: 114390

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.

llvm-svn: 114389

Fixes potential ambiguity problems on VS 2010.

Patch by nobled!

llvm-svn: 110029

llvm-svn: 109608

llvm-svn: 107602

PrologEpilog code, and use it to determine whether
the asm forces stack alignment or not.  gcc consistently
does not do this for GCC-style asms; Apple gcc inconsistently
sometimes does it for asm blocks.  There is no
convenient place to put a bit in either the SDNode or
the MachineInstr form, so I've added an extra operand
to each; unlovely, but it does allow for expansion for
more bits, should we need it.  PR 5125.  Some
existing testcases are affected.
The operand lists of the SDNode and MachineInstr forms
are indexed with awesome mnemonics, like "2"; I may
fix this someday, but not now.  I'm not making it any
worse.  If anyone is inspired I think you can find all
the right places from this patch.

llvm-svn: 107506

llvm-svn: 107208

on calls and similar instructions.

llvm-svn: 106353

instruction defines subregisters.

Any existing subreg indices on the original instruction are preserved or
composed with the new subreg index.

Also substitute multiple operands mentioning the original register by using the
new MachineInstr::substituteRegister() function. This is necessary because there
will soon be <imp-def> operands added to non read-modify-write partial
definitions. This instruction:

  %reg1234:foo = FLAP %reg1234<imp-def>

will reMaterialize(%reg3333, bar) like this:

  %reg3333:bar-foo = FLAP %reg333:bar<imp-def>

Finally, replace the TargetRegisterInfo pointer argument with a reference to
indicate that it cannot be NULL.

llvm-svn: 105358

The comment about ordering of subreg indices is no longer true.
This exposed a bug in the new substVirtReg method that is also fixed.

llvm-svn: 105294

implementation that is correct for most targets. Tablegen will override where
needed.

Add MachineOperand::subst{Virt,Phys}Reg methods that correctly handle existing
subreg indices when sustituting registers.

llvm-svn: 104985

llvm-svn: 104628

that are aliases of the specified register.
- Rename modifiesRegister to definesRegister since it's looking a def of the
specific register or one of its super-registers. It's not looking for def of a
sub-register or alias that could change the specified register.
- Added modifiesRegister to look for defs of aliases.

llvm-svn: 104377

reads or writes a register.

This takes partial redefines and undef uses into account.

Don't actually use it yet. That caused miscompiles.

llvm-svn: 104372

This reverts r104322. I think it was causing miscompilations.

llvm-svn: 104323

This correctly handles partial redefines and undef uses.

llvm-svn: 104322

<imp-def> operand for the full register. This ensures that the full physical
register is marked live after register allocation.

llvm-svn: 104320

partial redefines.

We are going to treat a partial redefine of a virtual register as a
read-modify-write:

  %reg1024:6 = OP

Unless the register is fully clobbered:

  %reg1024:6 = OP, %reg1024<imp-def>

MachineInstr::readsVirtualRegister() knows the difference. The first case is a
read, the second isn't.

llvm-svn: 104149

when they move instructions.

llvm-svn: 103737

Before:
DBG_VALUE %RSI, 0, !-1; dbg:SimpleRegisterCoalescing.cpp:2707
Now:
DBG_VALUE %RSI, 0, !"this"; dbg:SimpleRegisterCoalescing.cpp:2707

llvm-svn: 102518

llvm-svn: 100850

llvm-svn: 100849

%RDI<def,dead> = MOV64rr %RAX<kill>, %EDI<imp-def>

llvm-svn: 100804

MachineOperand::isIdenticalTo wasn't handling metadata operands.

llvm-svn: 100636

llvm-svn: 100215