Merging r215806:
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@215874 91177308-0d34-0410-b5e6-96231b3b80d8
Merging r215685:
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r215685 | wschmidt | 2014-08-14 18:25:26 -0700 (Thu, 14 Aug 2014) | 69 lines

[PPC64] Add missing dependency on X2 to LDinto_toc.

The LDinto_toc pattern has been part of 64-bit PowerPC for a long
time, and represents loading from a memory location into the TOC
register (X2).  However, this pattern doesn't explicitly record that
it modifies that register.  This patch adds the missing dependency.

It was very surprising to me that this has never shown up as a problem
in the past, and that we only saw this problem recently in a single
scenario when building a self-hosted clang.  It turns out that in most
cases we have another dependency present that keeps the LDinto_toc
instruction tied in place.  LDinto_toc is used for TOC restore
following a call site, so this is a typical sequence:

   BCTRL8 <regmask>, %CTR8<imp-use>, %RM<imp-use>, %X3<imp-use>, %X12<imp-use>, %X1<imp-def>, ...
   LDinto_toc 24, %X1
   ADJCALLSTACKUP 96, 0, %R1<imp-def>, %R1<imp-use>

Because the LDinto_toc is inserted prior to the ADJCALLSTACKUP, there
is a natural anti-dependency between the two that keeps it in place.

Therefore we don't usually see a problem.  However, in one particular
case, one call is followed immediately by another call, and the second
call requires a parameter that is a TOC-relative address.  This is the
code sequence:

  BCTRL8 <regmask>, %CTR8<imp-use>, %RM<imp-use>, %X3<imp-use>, %X4<imp-use>, %X5<imp-use>, %X12<imp-use>, %X1<imp-def>, ...
  LDinto_toc 24, %X1
  ADJCALLSTACKUP 96, 0, %R1<imp-def>, %R1<imp-use>
  ADJCALLSTACKDOWN 96, %R1<imp-def>, %R1<imp-use>
  %vreg39<def> = ADDIStocHA %X2, <ga:@.str>; G8RC_and_G8RC_NOX0:%vreg39
  %vreg40<def> = ADDItocL %vreg39<kill>, <ga:@.str>; G8RC:%vreg40 G8RC_and_G8RC_NOX0:%vreg39

Note that the back-to-back stack adjustments are the same size!  The
back end is smart enough to recognize this and optimize them away:

  BCTRL8 <regmask>, %CTR8<imp-use>, %RM<imp-use>, %X3<imp-use>, %X4<imp-use>, %X5<imp-use>, %X12<imp-use>, %X1<imp-def>, ...
  LDinto_toc 24, %X1
  %vreg39<def> = ADDIStocHA %X2, <ga:@.str>; G8RC_and_G8RC_NOX0:%vreg39
  %vreg40<def> = ADDItocL %vreg39<kill>, <ga:@.str>; G8RC:%vreg40 G8RC_and_G8RC_NOX0:%vreg39

Now there is nothing to prevent the ADDIStocHA instruction from moving
ahead of the LDinto_toc instruction, and because of the longest-path
heuristic, this is what happens.

With the accompanying patch, %X2 is represented as an implicit def:

  BCTRL8 <regmask>, %CTR8<imp-use>, %RM<imp-use>, %X3<imp-use>, %X4<imp-use>, %X5<imp-use>, %X12<imp-use>, %X1<imp-def>, ...
  LDinto_toc 24, %X1, %X2<imp-def,dead>
  ADJCALLSTACKUP 96, 0, %R1<imp-def,dead>, %R1<imp-use>
  ADJCALLSTACKDOWN 96, %R1<imp-def,dead>, %R1<imp-use>
  %vreg39<def> = ADDIStocHA %X2, <ga:@.str>; G8RC_and_G8RC_NOX0:%vreg39
  %vreg40<def> = ADDItocL %vreg39<kill>, <ga:@.str>; G8RC:%vreg40 G8RC_and_G8RC_NOX0:%vreg39

So now when the two stack adjustments are removed, ADDIStocHA is
prevented from being moved above LDinto_toc.

I have not yet created a test case for this, because the original
failure occurs on a relatively large function that needs reduction.
However, this is a fairly serious bug, despite its infrequency, and I
wanted to get this patch onto the list as soon as possible so that it
can be considered for a 3.5 backport.  I'll work on whittling down a
test case.

Have we missed the boat for 3.5 at this point?

Thanks,
Bill

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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@215878 91177308-0d34-0410-b5e6-96231b3b80d8
Merging r215711:
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r215711 | wschmidt | 2014-08-15 06:51:57 -0700 (Fri, 15 Aug 2014) | 8 lines

[PPC64] Add test case for r215685.

I had deferred adding this test case until I could get it down to a
reasonable size.  That's done now.

Thanks,
Bill

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Merging r216064:
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r216064 | kongyi | 2014-08-20 03:40:20 -0700 (Wed, 20 Aug 2014) | 9 lines

ARM: Fix codegen for rbit intrinsic

LLVM generates illegal `rbit r0, #352` instruction for rbit intrinsic.
According to ARM ARM, rbit only takes register as argument, not immediate.
The correct instruction should be rbit <Rd>, <Rm>.

The bug was originally introduced in r211057.

Differential Revision: http://reviews.llvm.org/D4980
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Update to include ISPC. By Dmitry Babokin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@216760 91177308-0d34-0410-b5e6-96231b3b80d8
Include blurb about Likely. By Josh Klontz.

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Update lang ref.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@216950 91177308-0d34-0410-b5e6-96231b3b80d8
Update release notes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@216951 91177308-0d34-0410-b5e6-96231b3b80d8
Update PowerPC target information.

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Merging r217484:
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r217484 | delcypher | 2014-09-10 11:18:59 +0100 (Wed, 10 Sep 2014) | 13 lines

Attempt to fix PR20884

This fixes the generation of broken LLVMExports.cmake file by
the Autoconf/Makefile build system when --enable-shared is passed to
configure.

When --enable_shared is passed the Makefile.rules does not set the
LLVMConfigLibs variable which cmake/modules/Makefile previously relied
on. Now it runs the llvm-config command itself to get the library names.

This still isn't perfect because the generated LLVM targets refer to the
static libraries and not the shared library but that is much larger
problem to fix.
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git-svn-id: https://llvm.org/svn/llvm-project/llvm/branches/release_35@217638 91177308-0d34-0410-b5e6-96231b3b80d8
Merging r217490:
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r217490 | delcypher | 2014-09-10 12:09:23 +0100 (Wed, 10 Sep 2014) | 4 lines

Don't attempt to run llvm-config in cmake/modules/Makefile when doing
``make clean`` because it won't be available.

This is an attempt to unbreak buildbots broken by r217484.
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