llvm-svn: 199033

The implicit immediate 0 forms are assembly aliases, not distinct instruction
encodings.  Fix the initial implementation introduced in r198914 to an alias to
avoid two separate instruction definitions for the same encoding.

An InstAlias is insufficient in this case as the necessary due to the need to
add a new additional operand for the implicit zero.  By using the AsmPsuedoInst,
fall back to the C++ code to transform the instruction to the equivalent
_POST_IMM form, inserting the additional implicit immediate 0.

llvm-svn: 199032

llvm-svn: 199031

This is different from the argument passing convention which puts the
first float argument in %f1.

With this patch, all returned floats are treated as if the 'inreg' flag
were set. This means multiple float return values get packed in %f0,
%f1, %f2, ...

Note that when returning a struct in registers, clang will set the
'inreg' flag on the return value, so that behavior is unchanged. This
also happens when returning a float _Complex.

llvm-svn: 199028

assemble the various mul instructions.

llvm-svn: 199026

case when the lookup table doesn't have any holes.

This means we can build a lookup table for switches like this:

  switch (x) {
    case 0: return 1;
    case 1: return 2;
    case 2: return 3;
    case 3: return 4;
    default: exit(1);
  }

The default case doesn't yield a constant result here, but that doesn't matter,
since a default result is only necessary for filling holes in the lookup table,
and this table doesn't have any holes.

This makes us transform 505 more switches in a clang bootstrap, and shaves 164 KB
off the resulting clang binary.

llvm-svn: 199025

llvm-svn: 199024

A 32-bit immediate value can be formed from a constant expression and loaded
into a register.  Add support to emit this into an object file.  Because this
value is a constant, a relocation must *not* be produced for it.

llvm-svn: 199023

I saw no compile or execution time regressions on x86_64 -mavx -O3.

radar://13075509

llvm-svn: 199015

[Sparc] Bundle instruction with delay slow and its filler. Now, we can use -verify-machineinstrs with SPARC backend.

llvm-svn: 199014

Patch by Jasper Neumann!

llvm-svn: 199007

mode that can be used to debug the execution of everything.

No support for analyses here, that will come later. This already helps
show parts of the opt commandline integration that isn't working. Tests
of that will start using it as the bugs are fixed.

llvm-svn: 199004

Excuse me, I hope msc16 builders would be fine till its end day.
Introduce nullptr then. ;)

llvm-svn: 199001

Use separate callee-save masks for XMM and YMM registers for anyregcc on X86 and
select the proper mask depending on the target cpu we compile for.

llvm-svn: 198985

llvm-svn: 198981

llvm-svn: 198980

llvm-svn: 198979

1- Use the line_iterator class to read profile files.

2- Allow comments in profile file. Lines starting with '#'
   are completely ignored while reading the profile.

3- Add parsing support for discriminators and indirect call samples.

   Our external profiler can emit more profile information that we are
   currently not handling. This patch does not add new functionality to
   support this information, but it allows profile files to provide it.

   I will add actual support later on (for at least one of these
   features, I need support for DWARF discriminators in Clang).

   A sample line may contain the following additional information:

   Discriminator. This is used if the sampled program was compiled with
   DWARF discriminator support
   (http://wiki.dwarfstd.org/index.php?title=Path_Discriminators). This
   is currently only emitted by GCC and we just ignore it.

   Potential call targets and samples. If present, this line contains a
   call instruction. This models both direct and indirect calls. Each
   called target is listed together with the number of samples. For
   example,

                    130: 7  foo:3  bar:2  baz:7

   The above means that at relative line offset 130 there is a call
   instruction that calls one of foo(), bar() and baz(). With baz()
   being the relatively more frequent call target.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2355

4- Simplify format of profile input file.

   This implements earlier suggestions to simplify the format of the
   sample profile file. The symbol table is not necessary and function
   profiles do not need to know the number of samples in advance.

   Differential Revision: http://llvm-reviews.chandlerc.com/D2419

llvm-svn: 198973

This adds a propagation heuristic to convert instruction samples
into branch weights. It implements a similar heuristic to the one
implemented by Dehao Chen on GCC.

The propagation proceeds in 3 phases:

1- Assignment of block weights. All the basic blocks in the function
   are initial assigned the same weight as their most frequently
   executed instruction.

2- Creation of equivalence classes. Since samples may be missing from
   blocks, we can fill in the gaps by setting the weights of all the
   blocks in the same equivalence class to the same weight. To compute
   the concept of equivalence, we use dominance and loop information.
   Two blocks B1 and B2 are in the same equivalence class if B1
   dominates B2, B2 post-dominates B1 and both are in the same loop.

3- Propagation of block weights into edges. This uses a simple
   propagation heuristic. The following rules are applied to every
   block B in the CFG:

   - If B has a single predecessor/successor, then the weight
     of that edge is the weight of the block.

   - If all the edges are known except one, and the weight of the
     block is already known, the weight of the unknown edge will
     be the weight of the block minus the sum of all the known
     edges. If the sum of all the known edges is larger than B's weight,
     we set the unknown edge weight to zero.

   - If there is a self-referential edge, and the weight of the block is
     known, the weight for that edge is set to the weight of the block
     minus the weight of the other incoming edges to that block (if
     known).

Since this propagation is not guaranteed to finalize for every CFG, we
only allow it to proceed for a limited number of iterations (controlled
by -sample-profile-max-propagate-iterations). It currently uses the same
GCC default of 100.

Before propagation starts, the pass builds (for each block) a list of
unique predecessors and successors. This is necessary to handle
identical edges in multiway branches. Since we visit all blocks and all
edges of the CFG, it is cleaner to build these lists once at the start
of the pass.

Finally, the patch fixes the computation of relative line locations.
The profiler emits lines relative to the function header. To discover
it, we traverse the compilation unit looking for the subprogram
corresponding to the function. The line number of that subprogram is the
line where the function begins. That becomes line zero for all the
relative locations.

llvm-svn: 198972

llvm-svn: 198958

llvm-svn: 198955

llvm-svn: 198954

 for (i = 0; i < N; ++i)
   A[i * Stride1] += B[i * Stride2];

We take loops like this and check that the symbolic strides 'Strided1/2' are one
and drop to the scalar loop if they are not.

This is currently disabled by default and hidden behind the flag
'enable-mem-access-versioning'.

radar://13075509

llvm-svn: 198950

llvm-svn: 198945

The disassembler would no longer be able to disambiguage between the two
variants (explicit immediate #0 vs implicit, omitted #0) for the ldrt, strt,
ldrbt, strbt mnemonics as both versions indicated the disassembler routine.

llvm-svn: 198944

llvm-svn: 198941

This change was requested to avoid confusion if we ever support non windows coff
systems.

llvm-svn: 198938

llvm-svn: 198937

The GNU assembler supports prefixing the expression with a '#' to indiciate that
the value that is being moved is infact a constant.  This improves the
compatibility of the integrated assembler's parser for this.

llvm-svn: 198916

The GNU assembler has an extension that allows for the elision of the paired
register (dt2) for the LDRD and STRD mnemonics.  Add support for this in the
assembly parser.  Canonicalise the usage during the instruction parsing from
the specified version.

llvm-svn: 198915

The ARM ARM indicates the mnemonics as follows:

  ldrbt{<c>}{<q>} <Rt>, [<Rn>], {, #+/-<imm>}
  ldrt{<c>}{<q>} <Rt>, [<Rn>] {, #+/-<imm>}
  strbt{<c>}{<q>} <Rt>, [<Rn>] {, #<imm>}
  strt{<c>}{<q>} <Rt>, [<Rn>] {, #+/-<imm>}

This improves the parser to deal with the implicit immediate 0 for the mnemonics
as per the specification.

Thanks to Joerg Sonnenberger for the tests!

llvm-svn: 198914

[Sparc] Emit retl/ret instead of jmp instruction. It improves the readability of the assembly generated.

llvm-svn: 198910

[Sparc] Add support for parsing jmpl instruction and make indirect call and jmp instructions as aliases to jmpl.

llvm-svn: 198909

This reverts commit r198865 which reverts r198851.

ASan identified a use-of-uninitialized of the DwarfTypeUnit::Ty variable
in skeleton type units.

llvm-svn: 198908

branch to the next instruction.  This can not be encoded but can be
turned into a NOP.

rdar://15062072

llvm-svn: 198904

llvm-svn: 198893

llvm-svn: 198889

This reverts r198854.

llvm-svn: 198879

It caused undefined behavior. DwarfTypeUnit::Ty might not be initialized properly, I guess.

llvm-svn: 198865

Detailed description is here:
http://llvm.org/bugs/show_bug.cgi?id=18000#c16

For participation in bugfix process special thanks to David Wiberg.

llvm-svn: 198863