Remove unnecessary FIXME

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159182 91177308-0d34-0410-b5e6-96231b3b80d8
Enable the new LoopInfo algorithm by default.

The primary advantage is that loop optimizations will be applied in a
stable order. This helps debugging and unit test creation. It is also
a better overall implementation without pathologically bad performance
on deep functions.

On large functions (llvm-stress --size=200000 | opt -loops)
Before: 0.1263s
After:  0.0225s

On deep functions (after tweaking llvm-stress, thanks Nadav):
Before: 0.2281s
After:  0.0227s

See r158790 for more comments.

The loop tree is now consistently generated in forward order, but loop
passes are applied in reverse order over the program. If we have a
loop optimization that prefers forward order, that can easily be
achieved by adding a different type of LoopPassManager.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159183 91177308-0d34-0410-b5e6-96231b3b80d8
Remove some duplicate instructions that exist only to given different mnemonics for the assembler. Use InstAlias instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159184 91177308-0d34-0410-b5e6-96231b3b80d8
Update a bunch of stale comments that dated from when this folled the
very first (and worst) placement algorithm. These should now more
accurately reflect the reality of the pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159185 91177308-0d34-0410-b5e6-96231b3b80d8
Shuffle optimization for AVX/AVX2.
The current patch optimizes frequently used shuffle patterns and gives these instruction sequence reduction.
Before:
      vshufps $-35, %xmm1, %xmm0, %xmm2 ## xmm2 = xmm0[1,3],xmm1[1,3]
       vpermilps       $-40, %xmm2, %xmm2 ## xmm2 = xmm2[0,2,1,3]
       vextractf128    $1, %ymm1, %xmm1
       vextractf128    $1, %ymm0, %xmm0
       vshufps $-35, %xmm1, %xmm0, %xmm0 ## xmm0 = xmm0[1,3],xmm1[1,3]
       vpermilps       $-40, %xmm0, %xmm0 ## xmm0 = xmm0[0,2,1,3]
       vinsertf128     $1, %xmm0, %ymm2, %ymm0
After:
      vshufps $13, %ymm0, %ymm1, %ymm1 ## ymm1 = ymm1[1,3],ymm0[0,0],ymm1[5,7],ymm0[4,4]
      vshufps $13, %ymm0, %ymm0, %ymm0 ## ymm0 = ymm0[1,3,0,0,5,7,4,4]
      vunpcklps       %ymm1, %ymm0, %ymm0 ## ymm0 = ymm0[0],ymm1[0],ymm0[1],ymm1[1],ymm0[4],ymm1[4],ymm0[5],ymm1[5]



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159188 91177308-0d34-0410-b5e6-96231b3b80d8
Rename to match other X86_64* names.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159196 91177308-0d34-0410-b5e6-96231b3b80d8
Removed unused variable

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159197 91177308-0d34-0410-b5e6-96231b3b80d8
Sphyinxify the Bugpoint document.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159199 91177308-0d34-0410-b5e6-96231b3b80d8
IntegersSubsetMapping: removed exclude operation, it will replaced with more universal "diff" operation in next commit.
Changes was separated onto two commits for better readability.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159200 91177308-0d34-0410-b5e6-96231b3b80d8
IntegersSubsetMapping: implemented "diff" operation. Operation allows at the same time perform up to three operations:
- LHS exclude RHS
- LHS intersect RHS (LHS successors will keeped)
- RHS exclude LHS
The complexity is N+M, where
  N is size of LHS
  M is size of RHS.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159201 91177308-0d34-0410-b5e6-96231b3b80d8
Replacing zero-sized alloca's with a null pointer is too aggressive, instead
merge all zero-sized alloca's into one, fixing c43204g from the Ada ACATS
conformance testsuite.  What happened there was that a variable sized object
was being allocated on the stack, "alloca i8, i32 %size".  It was then being
passed to another function, which tested that the address was not null (raising
an exception if it was) then manipulated %size bytes in it (load and/or store).
The optimizers cleverly managed to deduce that %size was zero (congratulations
to them, as it isn't at all obvious), which made the alloca zero size, causing
the optimizers to replace it with null, which then caused the check mentioned
above to fail, and the exception to be raised, wrongly.  Note that no loads
and stores were actually being done to the alloca (the loop that does them is
executed %size times, i.e. is not executed), only the not-null address check.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159202 91177308-0d34-0410-b5e6-96231b3b80d8
There are a number of generic inline asm operand modifiers that
up to r158925 were handled as processor specific. Making them 
generic and putting tests for these modifiers in the CodeGen/Generic
directory caused a number of targets to fail. 

This commit addresses that problem by having the targets call 
the generic routine for generic modifiers that they don't currently
have explicit code for.

For now only generic print operands 'c' and 'n' are supported.vi


Affected files:

    test/CodeGen/Generic/asm-large-immediate.ll
    lib/Target/PowerPC/PPCAsmPrinter.cpp
    lib/Target/NVPTX/NVPTXAsmPrinter.cpp
    lib/Target/ARM/ARMAsmPrinter.cpp
    lib/Target/XCore/XCoreAsmPrinter.cpp
    lib/Target/X86/X86AsmPrinter.cpp
    lib/Target/Hexagon/HexagonAsmPrinter.cpp
    lib/Target/CellSPU/SPUAsmPrinter.cpp
    lib/Target/Sparc/SparcAsmPrinter.cpp
    lib/Target/MBlaze/MBlazeAsmPrinter.cpp
    lib/Target/Mips/MipsAsmPrinter.cpp
    
MSP430 isn't represented because it did not even run with
the long existing 'c' modifier and it was not apparent what
needs to be done to get it inline asm ready.

Contributer: Jack Carter



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159203 91177308-0d34-0410-b5e6-96231b3b80d8
IntegersSubsetTest: Due to compilation failure with -std=c11, replaced -1UL with NOT_A_NUMBER constant (0xffff).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159207 91177308-0d34-0410-b5e6-96231b3b80d8
Allow targets to inject passes before the virtual register rewriter.

Such passes can be used to tweak the register assignments in a
target-dependent way, for example to avoid write-after-write
dependencies.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159209 91177308-0d34-0410-b5e6-96231b3b80d8
Fix ThreadLocalImpl::getInstance for --disable-threads.

PR13114.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159210 91177308-0d34-0410-b5e6-96231b3b80d8
Teach TableGen to put chains on more instructions

When generating selection tables for Pat instances, TableGen relied on
an output Instruction's Pattern field being set to infer whether a
chain should be added.

This patch adds additional logic to check various flag fields so that
correct code can be generated even if Pattern is unset.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159217 91177308-0d34-0410-b5e6-96231b3b80d8
X86: add GATHER intrinsics (AVX2) in LLVM

Support the following intrinsics:
llvm.x86.avx2.gather.d.pd, llvm.x86.avx2.gather.q.pd
llvm.x86.avx2.gather.d.pd.256, llvm.x86.avx2.gather.q.pd.256
llvm.x86.avx2.gather.d.ps, llvm.x86.avx2.gather.q.ps
llvm.x86.avx2.gather.d.ps.256, llvm.x86.avx2.gather.q.ps.256

Modified Disassembler to handle VSIB addressing mode.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159221 91177308-0d34-0410-b5e6-96231b3b80d8
Fix llc's -print-before=pass and -print-after=pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159227 91177308-0d34-0410-b5e6-96231b3b80d8
Implement getHostCPUName for ARM/linux. This will be used to implement -march=native in clang.

The cpuid registers are only available in privileged mode so we don't have
an OS-independent way of implementing this. ARM doesn't provide a list of
processor IDs so the list is somewhat incomplete.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159228 91177308-0d34-0410-b5e6-96231b3b80d8
Remove a instcombine transform that (no longer?) makes sense:
    // C - zext(bool) -> bool ? C - 1 : C
    if (ZExtInst *ZI = dyn_cast<ZExtInst>(Op1))
      if (ZI->getSrcTy()->isIntegerTy(1))
        return SelectInst::Create(ZI->getOperand(0), SubOne(C), C);

This ends up forming sext i1 instructions that codegen to terrible code. e.g.
int blah(_Bool x, _Bool y) {
  return (x - y) + 1;
}
=>
        movzbl  %dil, %eax
        movzbl  %sil, %ecx
        shll    $31, %ecx
        sarl    $31, %ecx
        leal    1(%rax,%rcx), %eax
        ret


Without the rule, llvm now generates:
        movzbl  %sil, %ecx
        movzbl  %dil, %eax
        incl    %eax
        subl    %ecx, %eax
        ret

It also helps with ARM (and pretty much any target that doesn't have a sext i1 :-).

The transformation was done as part of Eli's r75531. He has given the ok to
remove it.

rdar://11748024


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159230 91177308-0d34-0410-b5e6-96231b3b80d8