Merge clang, llvm, lld, lldb, compiler-rt and libc++ 5.0.0 release.

MFC r309126 (by emaste):

  Correct lld llvm-tblgen dependency file name

MFC r309169:

  Get rid of separate Subversion mergeinfo properties for llvm-dwarfdump
  and llvm-lto.  The mergeinfo confuses Subversion enormously, and these
  directories will just use the mergeinfo for llvm itself.

MFC r312765:

  Pull in r276136 from upstream llvm trunk (by Wei Mi):

    Use ValueOffsetPair to enhance value reuse during SCEV expansion.

    In D12090, the ExprValueMap was added to reuse existing value during
    SCEV expansion. However, const folding and sext/zext distribution can
    make the reuse still difficult.

    A simplified case is: suppose we know S1 expands to V1 in
    ExprValueMap, and
      S1 = S2 + C_a
      S3 = S2 + C_b
    where C_a and C_b are different SCEVConstants. Then we'd like to
    expand S3 as V1 - C_a + C_b instead of expanding S2 literally. It is
    helpful when S2 is a complex SCEV expr and S2 has no entry in
    ExprValueMap, which is usually caused by the fact that S3 is
    generated from S1 after const folding.

    In order to do that, we represent ExprValueMap as a mapping from SCEV
    to ValueOffsetPair. We will save both S1->{V1, 0} and S2->{V1, C_a}
    into the ExprValueMap when we create SCEV for V1. When S3 is
    expanded, it will first expand S2 to V1 - C_a because of S2->{V1,
    C_a} in the map, then expand S3 to V1 - C_a + C_b.

    Differential Revision: https://reviews.llvm.org/D21313

  This should fix assertion failures when building OpenCV >= 3.1.

  PR:		215649

MFC r312831:

  Revert r312765 for now, since it causes assertions when building
  lang/spidermonkey24.

  Reported by:	antoine
  PR:		215649

MFC r316511 (by jhb):

  Add an implementation of __ffssi2() derived from __ffsdi2().

  Newer versions of GCC include an __ffssi2() symbol in libgcc and the
  compiler can emit calls to it in generated code.  This is true for at
  least GCC 6.2 when compiling world for mips and mips64.

  Reviewed by:	jmallett, dim
  Sponsored by:	DARPA / AFRL
  Differential Revision:	https://reviews.freebsd.org/D10086

MFC r318601 (by adrian):

  [libcompiler-rt] add bswapdi2/bswapsi2

  This is required for mips gcc 6.3 userland to build/run.

  Reviewed by:	emaste, dim
  Approved by:	emaste
  Differential Revision:	https://reviews.freebsd.org/D10838

MFC r318884 (by emaste):

  lldb: map TRAP_CAP to a trace trap

  In the absense of a more specific handler for TRAP_CAP (generated by
  ENOTCAPABLE or ECAPMODE while in capability mode) treat it as a trace
  trap.

  Example usage (testing the bug in PR219173):

  % proccontrol -m trapcap lldb usr.bin/hexdump/obj/hexdump -- -Cv -s 1 /bin/ls
  ...
  (lldb) run
  Process 12980 launching
  Process 12980 launched: '.../usr.bin/hexdump/obj/hexdump' (x86_64)
  Process 12980 stopped
  * thread #1, stop reason = trace
      frame #0: 0x0000004b80c65f1a libc.so.7`__sys_lseek + 10
  ...

  In the future we should have LLDB control the trapcap procctl itself
  (as it does with ASLR), as well as report a specific stop reason.
  This change eliminates an assertion failure from LLDB for now.

MFC r319796:

  Remove a few unneeded files from libllvm, libclang and liblldb.

MFC r319885 (by emaste):

  lld: ELF: Fix ICF crash on absolute symbol relocations.

  If two sections contained relocations to absolute symbols with the same
  value we would crash when trying to access their sections. Add a check that
  both symbols point to sections before accessing their sections, and treat
  absolute symbols as equal if their values are equal.

  Obtained from:	LLD commit r292578

MFC r319918:

  Revert r319796 for now, it can cause undefined references when linking
  in some circumstances.

  Reported by:	Shawn Webb <shawn.webb@hardenedbsd.org>

MFC r319957 (by emaste):

  lld: Add armelf emulation mode

  Obtained from:	LLD r305375

MFC r321369:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 (trunk r308421).  Upstream has branched for the 5.0.0 release,
  which should be in about a month.  Please report bugs and regressions,
  so we can get them into the release.

  Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
  support to build; see UPDATING for more information.

MFC r321420:

  Add a few more object files to liblldb, which should solve errors when
  linking the lldb executable in some cases.  In particular, when the
  -ffunction-sections -fdata-sections options are turned off, or
  ineffective.

  Reported by:	Shawn Webb, Mark Millard

MFC r321433:

  Cleanup stale Options.inc files from the previous libllvm build for
  clang 4.0.0.  Otherwise, these can get included before the two newly
  generated ones (which are different) for clang 5.0.0.

  Reported by:	Mark Millard

MFC r321439 (by bdrewery):

  Move llvm Options.inc hack from r321433 for NO_CLEAN to lib/clang/libllvm.

  The files are only ever generated to .OBJDIR, not to WORLDTMP (as a
  sysroot) and are only ever included from a compilation.  So using
  a beforebuild target here removes the file before the compilation
  tries to include it.

MFC r321664:

  Pull in r308891 from upstream llvm trunk (by Benjamin Kramer):

    [CodeGenPrepare] Cut off FindAllMemoryUses if there are too many uses.

    This avoids excessive compile time. The case I'm looking at is
    Function.cpp from an old version of LLVM that still had the giant
    memcmp string matcher in it. Before r308322 this compiled in about 2
    minutes, after it, clang takes infinite* time to compile it. With
    this patch we're at 5 min, which is still bad but this is a
    pathological case.

    The cut off at 20 uses was chosen by looking at other cut-offs in LLVM
    for user scanning. It's probably too high, but does the job and is
    very unlikely to regress anything.

    Fixes PR33900.

    * I'm impatient and aborted after 15 minutes, on the bug report it was
      killed after 2h.

  Pull in r308986 from upstream llvm trunk (by Simon Pilgrim):

    [X86][CGP] Reduce memcmp() expansion to 2 load pairs (PR33914)

    D35067/rL308322 attempted to support up to 4 load pairs for memcmp
    inlining which resulted in regressions for some optimized libc memcmp
    implementations (PR33914).

    Until we can match these more optimal cases, this patch reduces the
    memcmp expansion to a maximum of 2 load pairs (which matches what we
    do for -Os).

    This patch should be considered for the 5.0.0 release branch as well

    Differential Revision: https://reviews.llvm.org/D35830

  These fix a hang (or extremely long compile time) when building older
  LLVM ports.

  Reported by:    antoine
  PR:             219139

MFC r321719:

  Pull in r309503 from upstream clang trunk (by Richard Smith):

    PR33902: Invalidate line number cache when adding more text to
    existing buffer.

    This led to crashes as the line number cache would report a bogus
    line number for a line of code, and we'd try to find a nonexistent
    column within the line when printing diagnostics.

  This fixes an assertion when building the graphics/champlain port.

  Reported by:	antoine, kwm
  PR:		219139

MFC r321723:

  Upgrade our copies of clang, llvm, lld and lldb to r309439 from the
  upstream release_50 branch.  This is just after upstream's 5.0.0-rc1.

MFC r322320:

  Upgrade our copies of clang, llvm and libc++ to r310316 from the
  upstream release_50 branch.

MFC r322326 (by emaste):

  lldb: Make i386-*-freebsd expression work on JIT path

  * Enable i386 ABI creation for freebsd
  * Added an extra argument in ABISysV_i386::PrepareTrivialCall for mmap
    syscall
  * Unlike linux, the last argument of mmap is actually 64-bit(off_t).
    This requires us to push an additional word for the higher order bits.
  * Prior to this change, ktrace dump will show mmap failures due to
    invalid argument coming from the 6th mmap argument.

  Submitted by:	Karnajit Wangkhem
  Differential Revision:	https://reviews.llvm.org/D34776

MFC r322360 (by emaste):

  lldb: Report inferior signals as signals, not exceptions, on FreeBSD

  This is the FreeBSD equivalent of LLVM r238549.

  This serves 2 purposes:

  * LLDB should handle inferior process signals SIGSEGV/SIGILL/SIGBUS/
    SIGFPE the way it is suppose to be handled. Prior to this fix these
    signals will neither create a coredump, nor exit from the debugger
    or work for signal handling scenario.
  * eInvalidCrashReason need not report "unknown crash reason" if we have
    a valid si_signo

  llvm.org/pr23699

  Patch by Karnajit Wangkhem

  Differential Revision:  https://reviews.llvm.org/D35223

  Submitted by:	Karnajit Wangkhem
  Obtained from:	LLVM r310591

MFC r322474 (by emaste):

  lld: Add `-z muldefs` option.

  Obtained from:	LLVM r310757

MFC r322740:

  Upgrade our copies of clang, llvm, lld and libc++ to r311219 from the
  upstream release_50 branch.

MFC r322855:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r311606 from
  the upstream release_50 branch.

  As of this version, lib/msun's trig test should also work correctly
  again (see bug 220989 for more information).

  PR:		220989

MFC r323112:

  Upgrade our copies of clang, llvm, lldb and compiler-rt to r312293 from
  the upstream release_50 branch.  This corresponds to 5.0.0 rc4.

  As of this version, the cad/stepcode port should now compile in a more
  reasonable time on i386 (see bug 221836 for more information).

  PR:		221836

MFC r323245:

  Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
  5.0.0 release (upstream r312559).

  Release notes for llvm, clang and lld will be available here soon:
  <http://releases.llvm.org/5.0.0/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/clang/docs/ReleaseNotes.html>
  <http://releases.llvm.org/5.0.0/tools/lld/docs/ReleaseNotes.html>

  Relnotes:	yes

(cherry picked from commit 12cd91cf4c6b96a24427c0de5374916f2808d263)

1 files changed, 61 insertions, 17 deletions

diff --git a/contrib/llvm/lib/Analysis/IVUsers.cpp b/contrib/llvm/lib/Analysis/IVUsers.cpp
index a661b01..c30feb9 100644
--- a/contrib/llvm/lib/Analysis/IVUsers.cpp
+++ b/contrib/llvm/lib/Analysis/IVUsers.cpp
@@ -76,9 +76,8 @@ static bool isInteresting(const SCEV *S, const Instruction *I, const Loop *L,
   // An add is interesting if exactly one of its operands is interesting.
   if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
     bool AnyInterestingYet = false;
-    for (SCEVAddExpr::op_iterator OI = Add->op_begin(), OE = Add->op_end();
-         OI != OE; ++OI)
-      if (isInteresting(*OI, I, L, SE, LI)) {
+    for (const auto *Op : Add->operands())
+      if (isInteresting(Op, I, L, SE, LI)) {
         if (AnyInterestingYet)
           return false;
         AnyInterestingYet = true;
@@ -118,6 +117,50 @@ static bool isSimplifiedLoopNest(BasicBlock *BB, const DominatorTree *DT,
   return true;
 }
 
+/// IVUseShouldUsePostIncValue - We have discovered a "User" of an IV expression
+/// and now we need to decide whether the user should use the preinc or post-inc
+/// value.  If this user should use the post-inc version of the IV, return true.
+///
+/// Choosing wrong here can break dominance properties (if we choose to use the
+/// post-inc value when we cannot) or it can end up adding extra live-ranges to
+/// the loop, resulting in reg-reg copies (if we use the pre-inc value when we
+/// should use the post-inc value).
+static bool IVUseShouldUsePostIncValue(Instruction *User, Value *Operand,
+                                       const Loop *L, DominatorTree *DT) {
+  // If the user is in the loop, use the preinc value.
+  if (L->contains(User))
+    return false;
+
+  BasicBlock *LatchBlock = L->getLoopLatch();
+  if (!LatchBlock)
+    return false;
+
+  // Ok, the user is outside of the loop.  If it is dominated by the latch
+  // block, use the post-inc value.
+  if (DT->dominates(LatchBlock, User->getParent()))
+    return true;
+
+  // There is one case we have to be careful of: PHI nodes.  These little guys
+  // can live in blocks that are not dominated by the latch block, but (since
+  // their uses occur in the predecessor block, not the block the PHI lives in)
+  // should still use the post-inc value.  Check for this case now.
+  PHINode *PN = dyn_cast<PHINode>(User);
+  if (!PN || !Operand)
+    return false; // not a phi, not dominated by latch block.
+
+  // Look at all of the uses of Operand by the PHI node.  If any use corresponds
+  // to a block that is not dominated by the latch block, give up and use the
+  // preincremented value.
+  for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i)
+    if (PN->getIncomingValue(i) == Operand &&
+        !DT->dominates(LatchBlock, PN->getIncomingBlock(i)))
+      return false;
+
+  // Okay, all uses of Operand by PN are in predecessor blocks that really are
+  // dominated by the latch block.  Use the post-incremented value.
+  return true;
+}
+
 /// AddUsersImpl - Inspect the specified instruction.  If it is a
 /// reducible SCEV, recursively add its users to the IVUsesByStride set and
 /// return true.  Otherwise, return false.
@@ -208,10 +251,16 @@ bool IVUsers::AddUsersImpl(Instruction *I,
       // The regular return value here is discarded; instead of recording
       // it, we just recompute it when we need it.
       const SCEV *OriginalISE = ISE;
-      ISE = TransformForPostIncUse(NormalizeAutodetect,
-                                   ISE, User, I,
-                                   NewUse.PostIncLoops,
-                                   *SE, *DT);
+
+      auto NormalizePred = [&](const SCEVAddRecExpr *AR) {
+        auto *L = AR->getLoop();
+        bool Result = IVUseShouldUsePostIncValue(User, I, L, DT);
+        if (Result)
+          NewUse.PostIncLoops.insert(L);
+        return Result;
+      };
+
+      ISE = normalizeForPostIncUseIf(ISE, NormalizePred, *SE);
 
       // PostIncNormalization effectively simplifies the expression under
       // pre-increment assumptions. Those assumptions (no wrapping) might not
@@ -219,8 +268,7 @@ bool IVUsers::AddUsersImpl(Instruction *I,
       // transformation is invertible.
       if (OriginalISE != ISE) {
         const SCEV *DenormalizedISE =
-          TransformForPostIncUse(Denormalize, ISE, User, I,
-              NewUse.PostIncLoops, *SE, *DT);
+            denormalizeForPostIncUse(ISE, NewUse.PostIncLoops, *SE);
 
         // If we normalized the expression, but denormalization doesn't give the
         // original one, discard this user.
@@ -338,11 +386,8 @@ const SCEV *IVUsers::getReplacementExpr(const IVStrideUse &IU) const {
 
 /// getExpr - Return the expression for the use.
 const SCEV *IVUsers::getExpr(const IVStrideUse &IU) const {
-  return
-    TransformForPostIncUse(Normalize, getReplacementExpr(IU),
-                           IU.getUser(), IU.getOperandValToReplace(),
-                           const_cast<PostIncLoopSet &>(IU.getPostIncLoops()),
-                           *SE, *DT);
+  return normalizeForPostIncUse(getReplacementExpr(IU), IU.getPostIncLoops(),
+                                *SE);
 }
 
 static const SCEVAddRecExpr *findAddRecForLoop(const SCEV *S, const Loop *L) {
@@ -353,9 +398,8 @@ static const SCEVAddRecExpr *findAddRecForLoop(const SCEV *S, const Loop *L) {
   }
 
   if (const SCEVAddExpr *Add = dyn_cast<SCEVAddExpr>(S)) {
-    for (SCEVAddExpr::op_iterator I = Add->op_begin(), E = Add->op_end();
-         I != E; ++I)
-      if (const SCEVAddRecExpr *AR = findAddRecForLoop(*I, L))
+    for (const auto *Op : Add->operands())
+      if (const SCEVAddRecExpr *AR = findAddRecForLoop(Op, L))
         return AR;
     return nullptr;
   }