The inline asm operand constraint is initially encoded in the virtual
register for the operand, but that register class may change during
coalescing, and the original constraint is lost.

Encode the original register class as part of the flag word for each
inline asm operand.  This makes it possible to recover the actual
constraint required by inline asm, just like we can for normal
instructions.

llvm-svn: 141833

llvm-svn: 140767

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

llvm-svn: 138773

llvm-svn: 138437

Normally, a partial register def is treated as reading the
super-register unless it also defines the full register like this:

  %vreg110:sub_32bit<def> = COPY %vreg77:sub_32bit, %vreg110<imp-def>

This patch also uses the <undef> flag on partial defs to recognize
non-reading operands:

  %vreg110:sub_32bit<def,undef> = COPY %vreg77:sub_32bit

This fixes a subtle bug in RegisterCoalescer where LIS->shrinkToUses
would treat a coalesced copy as still reading the register, extending
the live range artificially.

My test case only works when I disable DCE so a dead copy is left for
RegisterCoalescer, so I am not including it.

<rdar://problem/9967101>

llvm-svn: 138018

llvm-svn: 136916

If known DebugLocs do not match then two DBG_VALUE machine instructions are not identical. For example,

        DBG_VALUE 3.310000e+02, 0, !"ds"; dbg:sse.stepfft.c:138:18 @[ sse.stepfft.c:32:10 ]
        DBG_VALUE 3.310000e+02, 0, !"ds"; dbg:sse.stepfft.c:138:18 @[ sse.stepfft.c:31:10 ]

These two MIs represent identical value, 3.31...,  for one variable, ds, but they are not identical because the represent two separate instances of inlined variable "ds". 

llvm-svn: 134620

Add a MI->emitError() method that the backend can use to report errors
related to inline assembly. Call it from X86FloatingPoint.cpp when the
constraints are wrong.

This enables proper clang diagnostics from the backend:

$ clang -c pr30848.c
pr30848.c:5:12: error: Inline asm output regs must be last on the x87 stack
  __asm__ ("" : "=u" (d));  /* { dg-error "output regs" } */
           ^
1 error generated.

llvm-svn: 134307

llvm-svn: 134287

sink them into MC layer.
- Added MCInstrInfo, which captures the tablegen generated static data. Chang
TargetInstrInfo so it's based off MCInstrInfo.

llvm-svn: 134021

Both become <earlyclobber> defs on the INLINEASM MachineInstr, but we
now use two different asm operand kinds.

The new Kind_Clobber is treated identically to the old
Kind_RegDefEarlyClobber for now, but x87 floating point stack inline
assembly does care about the difference.

This will pop a register off the stack:

  asm("fstp %st" : : "t"(x) : "st");

While this will pop the input and push an output:

  asm("fst %st" : "=&t"(r) : "t"(x));

We need to know if ST0 was a clobber or an output operand, and we can't
depend on <dead> flags for that.

llvm-svn: 133902

The INLINEASM MachineInstrs have an immediate operand describing each
original inline asm operand. Decode the bits in MachineInstr::print() so
it is easier to read:

  INLINEASM <es:rorq $1,$0>, $0:[regdef], %vreg0<def>, %vreg1<def>, $1:[imm], 1, $2:[reguse] [tiedto:$0], %vreg2, %vreg3, $3:[regdef-ec], %EFLAGS<earlyclobber,imp-def>

llvm-svn: 133901

llvm-svn: 133821

markers. In some cases a register def is dead on one path, but not on
another.

This is passing Clang self-hosting.

llvm-svn: 131214

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