Fix live-out reg logic to not insert over-aggressive AssertZExt
instructions. This fixes lua.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68083 91177308-0d34-0410-b5e6-96231b3b80d8

X86 address mode isel tweak. If the base of the address is also used by a CopyToReg (i.e. it's likely live-out), do not fold the sub-expressions into the addressing mode to avoid computing the address twice. The CopyToReg use will be isel'ed to a LEA, re-use it for address instead.

This is not yet enabled.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68082 91177308-0d34-0410-b5e6-96231b3b80d8

Really, really fix PointerUnion3::is

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68079 91177308-0d34-0410-b5e6-96231b3b80d8

Except in asm-verbose mode, avoid printing labels for blocks that are
only reachable via fall-through edges. This dramatically reduces the
number of labels printed, and thus also the number of labels the
assembler must parse and remember.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68073 91177308-0d34-0410-b5e6-96231b3b80d8

Loop Index Split can eliminate a loop if it can determin if loop body is executed only once. There was a bug in determining IV based value of the iteration for which the loop body is executed. Fix it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68071 91177308-0d34-0410-b5e6-96231b3b80d8

Make PointerUnion3::get work properly

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68067 91177308-0d34-0410-b5e6-96231b3b80d8

When optimzing a mul by immediate into two, the resulting mul's should get a x86 specific node to avoid dag combiner from hacking on them further.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68066 91177308-0d34-0410-b5e6-96231b3b80d8

Turn a 2-address instruction into a 3-address one when it's profitable even if the two-address operand is killed.
e.g.
%reg1024<def> = MOV r1
%reg1025<def> = ADD %reg1024, %reg1026
r0            = MOV %reg1025

If it's not possible / profitable to commute ADD, then turning ADD into a LEA saves a copy.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68065 91177308-0d34-0410-b5e6-96231b3b80d8

update comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68060 91177308-0d34-0410-b5e6-96231b3b80d8

Balance out quote in debug output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68059 91177308-0d34-0410-b5e6-96231b3b80d8

Fix grammar-o in comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68057 91177308-0d34-0410-b5e6-96231b3b80d8

add a PointerUnion3 class and generalize PointerUnion to work with
anything pointer-like, which may or may not actually be a pointer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68056 91177308-0d34-0410-b5e6-96231b3b80d8

fix the PointerLikeTypeTraits specialization for PointerIntPair to
allow the traits to be specified as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68055 91177308-0d34-0410-b5e6-96231b3b80d8

Constify arguments in isSuccessor and isLayoutSuccessor.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68054 91177308-0d34-0410-b5e6-96231b3b80d8

Update the polygen grammer to reflect that zext and sext are no longer
valid argument attributes (zeroext and signext are).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68053 91177308-0d34-0410-b5e6-96231b3b80d8

docs/TestingGuide.html: correction to prev. text (objdir!=srcdir required for running test-suite), removed refs to llvm-test

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68051 91177308-0d34-0410-b5e6-96231b3b80d8

Fix comment to match function name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68050 91177308-0d34-0410-b5e6-96231b3b80d8

getEntryFor() may invalidate DenseMap iterator.
Walking an invalidated iterator is not a good idea.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68047 91177308-0d34-0410-b5e6-96231b3b80d8

Add ccc back for now.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68038 91177308-0d34-0410-b5e6-96231b3b80d8

Clearify local/global relocations wording

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68037 91177308-0d34-0410-b5e6-96231b3b80d8

Fix thinko: put stuff with both global and local relocations into data.rel{.ro}, not .local

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68036 91177308-0d34-0410-b5e6-96231b3b80d8

Tweak test for recent relro stuff

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68035 91177308-0d34-0410-b5e6-96231b3b80d8

Fix infinite looping

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68034 91177308-0d34-0410-b5e6-96231b3b80d8

Properly propagate Kind.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68033 91177308-0d34-0410-b5e6-96231b3b80d8

Do not propagate ELF-specific stuff (data.rel) into other targets. This simplifies code and also ensures correctness.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68032 91177308-0d34-0410-b5e6-96231b3b80d8

Add data.rel stuff

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68031 91177308-0d34-0410-b5e6-96231b3b80d8

fix some validation problems.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68026 91177308-0d34-0410-b5e6-96231b3b80d8

Forgot this test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68025 91177308-0d34-0410-b5e6-96231b3b80d8

Clarify section on setting up and running test-suite

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68023 91177308-0d34-0410-b5e6-96231b3b80d8

Updated the comment for isArithmeticShift() to match reality.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68016 91177308-0d34-0410-b5e6-96231b3b80d8

Constify check. This fixes PR3900.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68013 91177308-0d34-0410-b5e6-96231b3b80d8

Testcase for recent ro/relocs stuff

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68008 91177308-0d34-0410-b5e6-96231b3b80d8

IA64 is as weird as Alpha wrt r/o relocs :)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68007 91177308-0d34-0410-b5e6-96231b3b80d8

Alpha always requires global relocations to be r/w regardless of PIC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68006 91177308-0d34-0410-b5e6-96231b3b80d8

Honour relocation behaviour stuff for ro objects

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68005 91177308-0d34-0410-b5e6-96231b3b80d8

Extend the relocation tracker handler, so we can filter on different 'kinds' of relocations required.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@68004 91177308-0d34-0410-b5e6-96231b3b80d8

Fix PR3899: add support for extracting floats from vectors
when using -soft-float.
Based on a patch by Jakob Stoklund Olesen.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67996 91177308-0d34-0410-b5e6-96231b3b80d8

add missing space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67995 91177308-0d34-0410-b5e6-96231b3b80d8

add some comments, add a dyn_cast method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67992 91177308-0d34-0410-b5e6-96231b3b80d8

When forming sentinels for empty/tombstone, make sure to respect the
pointer's expected number of zero low-bits.

This should fix the breakage I introduced recently.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67990 91177308-0d34-0410-b5e6-96231b3b80d8

add helper method.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67989 91177308-0d34-0410-b5e6-96231b3b80d8

Add a simple type-safe bit-mangling pointer union class.  This allows
you to do things like:

  ///    PointerUnion<int*, float*> P;
  ///    P = (int*)0;
  ///    printf("%d %d", P.is<int*>(), P.is<float*>()); // prints "1 0"
  ///    X = P.get<int*>();     // ok.
  ///    Y = P.get<float*>();   // runtime assertion failure.
  ///    Z = P.get<double*>();  // does not compile.
  ///    P = (float*)0;
  ///    Y = P.get<float*>();   // ok.
  ///    X = P.get<int*>();     // runtime assertion failure.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67987 91177308-0d34-0410-b5e6-96231b3b80d8

Allow a specific PointerIntPair instance to use a specific Pointer trait:
some pointer instances have properties that not all of a type have.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67986 91177308-0d34-0410-b5e6-96231b3b80d8

Add a PointerLikeTypeTraits specialization for uintptr_t

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67985 91177308-0d34-0410-b5e6-96231b3b80d8

Value* only has 2 bits free as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67984 91177308-0d34-0410-b5e6-96231b3b80d8

Replace the PointerLikeTypeTraits::getNumLowBitsAvailable
function with a new NumLowBitsAvailable enum, which makes the
value available as an integer constant expression.

Add PointerLikeTypeTraits specializations for Instruction* and
Use** since they are only guaranteed 4-byte aligned.

Enhance PointerIntPair to know about (and enforce) the alignment
specified by PointerLikeTypeTraits.  This should allow things
like PointerIntPair<PointerIntPair<void*, 1,bool>, 1, bool>
because the inner one knows that 2 low bits are free.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67979 91177308-0d34-0410-b5e6-96231b3b80d8

rename PointerLikeTypeInto to PointerLikeTypeTraits, add trait for
# low bits free, and move to its own header.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67973 91177308-0d34-0410-b5e6-96231b3b80d8

now that you can put a PointerIntPair in a SmallPtrSet, remove some
hackish workarounds from memdep

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67971 91177308-0d34-0410-b5e6-96231b3b80d8

teach SmallPtrSet that PointerIntPair is "basically a pointer".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67970 91177308-0d34-0410-b5e6-96231b3b80d8

add a note

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67953 91177308-0d34-0410-b5e6-96231b3b80d8

Use array_lengthof

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67950 91177308-0d34-0410-b5e6-96231b3b80d8

Have only one definition of X86AddrNumOperands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67949 91177308-0d34-0410-b5e6-96231b3b80d8

Make code a bit less brittle by no hardcoding the number
of operands in an address in so many places.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67945 91177308-0d34-0410-b5e6-96231b3b80d8

Make check in CheckTailCallReturnConstraints for ignorable instructions between
a CALL and a RET node more generic. Add a test for tail calls with a void
return.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67943 91177308-0d34-0410-b5e6-96231b3b80d8

Update the Visual Studio docs. Patch by Stefanus!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67940 91177308-0d34-0410-b5e6-96231b3b80d8

Enable tail call optimization for functions that return a struct (bug 3664) and for functions that return types that need extending (e.g i1).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67934 91177308-0d34-0410-b5e6-96231b3b80d8

declare everything as class to avoid angering the VC++ gods.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67931 91177308-0d34-0410-b5e6-96231b3b80d8

add a traits class for SmallPtrSet that allows us to stick things that are
"basically pointers" into it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67930 91177308-0d34-0410-b5e6-96231b3b80d8

Optimize some 64-bit multiplication by constants into two lea's or one lea + shl since imulq is slow (latency 5). e.g.
x * 40
=>
shlq    $3, %rdi
leaq    (%rdi,%rdi,4), %rax

This has the added benefit of allowing more multiply to be folded into addressing mode. e.g.
a * 24 + b
=>
leaq    (%rdi,%rdi,2), %rax
leaq    (%rsi,%rax,8), %rax

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67917 91177308-0d34-0410-b5e6-96231b3b80d8

move a large method out of line.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67892 91177308-0d34-0410-b5e6-96231b3b80d8

Fix what surely must be a copy+pasto.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67881 91177308-0d34-0410-b5e6-96231b3b80d8

Initialize LiveOutInfo's APInt members to zero, as APInt's
default constructor produces an uninitialized APInt.
This fixes PR3896.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67879 91177308-0d34-0410-b5e6-96231b3b80d8

remove trailing whitespace

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67874 91177308-0d34-0410-b5e6-96231b3b80d8

"ghostify" the ilist<Function> sentinel

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67872 91177308-0d34-0410-b5e6-96231b3b80d8

Allow invertable -xno- style optins as well.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67862 91177308-0d34-0410-b5e6-96231b3b80d8

Revert r67844. This fixes the llvm-gcc-4.2 build on Darwin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67856 91177308-0d34-0410-b5e6-96231b3b80d8

Fix build on MacOS 10.4 systems (suggested by Mike Smith).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67855 91177308-0d34-0410-b5e6-96231b3b80d8

Fix this test so that it doesn't spuriously fail due to some
unrelated debugging output happening to contain the string "store".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67849 91177308-0d34-0410-b5e6-96231b3b80d8

Avoid hardcoding that X86 addresses have 4 operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67848 91177308-0d34-0410-b5e6-96231b3b80d8

Use less hard coded constants to make the code less brittle.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67846 91177308-0d34-0410-b5e6-96231b3b80d8

Reapply r66415, which was reverted in r66426 for
causing a bootstrap failure.  Bootstraps here on
x86-32-linux and x86-64-linux.  Requested by the
author Gabor Greif who says that a bug that might
have been causing the failure has since been fixed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67844 91177308-0d34-0410-b5e6-96231b3b80d8

I am trying to add a segment to the X86 addresses matching to
improve TLS support (see http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20090309/075220.html), but that code is VERY brittle.

This patch just makes it a bit more resistant.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67843 91177308-0d34-0410-b5e6-96231b3b80d8

Revert r67798: it breaks llvm-gcc bootstrap on x86-64-linux, presumably due to
a miscompilation.

make[4]: Entering directory `gcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/include'
if [ ! -d "./x86_64-unknown-linux-gnu/bits/stdtr1c++.h.gch" ]; then \
          mkdir -p ./x86_64-unknown-linux-gnu/bits/stdtr1c++.h.gch; \
        fi; \
        gcc-4.2.llvm-objects/./gcc/xgcc -shared-libgcc -Bgcc-4.2.llvm-objects/./gcc -nostdinc++
-Lgcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/src -Lgcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/src/.libs
-B/usr/local/gnat-llvm/x86_64-unknown-linux-gnu/bin/ -B/usr/local/gnat-llvm/x86_64-unknown-linux-gnu/lib/ -isystem
/usr/local/gnat-llvm/x86_64-unknown-linux-gnu/include -isystem /usr/local/gnat-llvm/x86_64-unknown-linux-gnu/sys-include -Winvalid-pch -Wno-deprecated -x
c++-header -g -O2  -D_GNU_SOURCE -Igcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/include/x86_64-unknown-linux-gnu
-Igcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/include -Igcc-4.2.llvm/libstdc++-v3/libsupc++ -O2 -g
gcc-4.2.llvm/libstdc++-v3/include/precompiled/stdtr1c++.h -o x86_64-unknown-linux-gnu/bits/stdtr1c++.h.gch/O2g.gch
In file included from gcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/include/tr1/repeat.h:247,
                 from gcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/include/tr1/functional:1098,
                 from gcc-4.2.llvm/libstdc++-v3/include/precompiled/stdtr1c++.h:53:
gcc-4.2.llvm-objects/x86_64-unknown-linux-gnu/libstdc++-v3/include/tr1/functional_iterate.h:417: internal compiler error: in ggc_recalculate_in_use_p, at
ggc-page.c:1602
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://llvm.org/bugs/> for instructions.
make[4]: *** [x86_64-unknown-linux-gnu/bits/stdtr1c++.h.gch/O2g.gch] Error 1

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67839 91177308-0d34-0410-b5e6-96231b3b80d8

Documentation update.

Expand a bit on various '--*-graph' options.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67836 91177308-0d34-0410-b5e6-96231b3b80d8

-write-graph now can be used with -o.

Makes it possible to set the output file name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67835 91177308-0d34-0410-b5e6-96231b3b80d8

Revert previous change in favour of an explanatory
comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67833 91177308-0d34-0410-b5e6-96231b3b80d8

A Release-Asserts build makes it sound like assertions
are turned on, while in fact they are turned off.  Name
this Release-NoAsserts instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67831 91177308-0d34-0410-b5e6-96231b3b80d8

Shrink wrapping in PEI: initial release. Finishing development, enable with --shrink-wrap.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67828 91177308-0d34-0410-b5e6-96231b3b80d8

Add a __builtin___memset_chk test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67815 91177308-0d34-0410-b5e6-96231b3b80d8

One more place to skip debug info.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67811 91177308-0d34-0410-b5e6-96231b3b80d8

While hoisting an instruction, update alias info set tracker.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67798 91177308-0d34-0410-b5e6-96231b3b80d8

Update to account for driver renaming.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67791 91177308-0d34-0410-b5e6-96231b3b80d8

-no-implicit-float means explicit fp operations are legal.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67784 91177308-0d34-0410-b5e6-96231b3b80d8

Add -march=x86.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67783 91177308-0d34-0410-b5e6-96231b3b80d8

Fix misc. small issues with debug visualization.

Detailed bug report:
http://llvm.org/bugs/show_bug.cgi?id=3873

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67768 91177308-0d34-0410-b5e6-96231b3b80d8

tADDhirr is a thumb instruction. Do not allow this code to be reached in non-thumb mode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67765 91177308-0d34-0410-b5e6-96231b3b80d8

Don't assign a new stack slot if the pre-alloc splitter already assigned one.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67764 91177308-0d34-0410-b5e6-96231b3b80d8

fix a few spelling errors and typos

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67758 91177308-0d34-0410-b5e6-96231b3b80d8

Use 'bool' for FoundRC

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67750 91177308-0d34-0410-b5e6-96231b3b80d8

Add -f to RUN line.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67744 91177308-0d34-0410-b5e6-96231b3b80d8

Pull transform from target-dependent code into target-independent code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67742 91177308-0d34-0410-b5e6-96231b3b80d8

no need for eh info

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67740 91177308-0d34-0410-b5e6-96231b3b80d8

fix warning in -asserts mode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67739 91177308-0d34-0410-b5e6-96231b3b80d8

fix some warnings in release-asserts mode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67738 91177308-0d34-0410-b5e6-96231b3b80d8

fix an apparently real bug exposed by a warning in -asserts mode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67737 91177308-0d34-0410-b5e6-96231b3b80d8

fix warning in -asserts build.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67736 91177308-0d34-0410-b5e6-96231b3b80d8

Add testcase for r67728.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67729 91177308-0d34-0410-b5e6-96231b3b80d8

Match this pattern so that we can generate simpler code:

  %a = ...
  %b = and i32 %a, 2
  %c = srl i32 %b, 1
  %d = br i32 %c,

into

  %a = ...
  %b = and %a, 2
  %c = X86ISD::CMP %b, 0
  %d = X86ISD::BRCOND %c ...

This applies only when the AND constant value has one bit set and the SRL
constant is equal to the log2 of the AND constant. The back-end is smart enough
to convert the result into a TEST/JMP sequence.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67728 91177308-0d34-0410-b5e6-96231b3b80d8

Doxygen-ify comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67727 91177308-0d34-0410-b5e6-96231b3b80d8

Skip debug info one more place.  (This one gets
called from llc, not opt, but it's an IR level
optimization nevertheless.)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@67724 91177308-0d34-0410-b5e6-96231b3b80d8