MFC 261991:

Upgrade our copy of llvm/clang to 3.4 release.  This version supports
all of the features in the current working draft of the upcoming C++
standard, provisionally named C++1y.

The code generator's performance is greatly increased, and the loop
auto-vectorizer is now enabled at -Os and -O2 in addition to -O3.  The
PowerPC backend has made several major improvements to code generation
quality and compile time, and the X86, SPARC, ARM32, Aarch64 and SystemZ
backends have all seen major feature work.

Release notes for llvm and clang can be found here:
<http://llvm.org/releases/3.4/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.4/tools/clang/docs/ReleaseNotes.html>

MFC 262121 (by emaste):

Update lldb for clang/llvm 3.4 import

This commit largely restores the lldb source to the upstream r196259
snapshot with the addition of threaded inferior support and a few bug
fixes.

Specific upstream lldb revisions restored include:
   SVN      git
  181387  779e6ac
  181703  7bef4e2
  182099  b31044e
  182650  f2dcf35
  182683  0d91b80
  183862  15c1774
  183929  99447a6
  184177  0b2934b
  184948  4dc3761
  184954  007e7bc
  186990  eebd175

Sponsored by:	DARPA, AFRL

MFC 262186 (by emaste):

Fix mismerge in r262121

A break statement was lost in the merge.  The error had no functional
impact, but restore it to reduce the diff against upstream.

MFC 262303:

Pull in r197521 from upstream clang trunk (by rdivacky):

  Use the integrated assembler by default on FreeBSD/ppc and ppc64.

Requested by:	jhibbits

MFC 262611:

Pull in r196874 from upstream llvm trunk:

  Fix a crash that occurs when PWD is invalid.

  MCJIT needs to be able to run in hostile environments, even when PWD
  is invalid. There's no need to crash MCJIT in this case.

  The obvious fix is to simply leave MCContext's CompilationDir empty
  when PWD can't be determined. This way, MCJIT clients,
  and other clients that link with LLVM don't need a valid working directory.

  If we do want to guarantee valid CompilationDir, that should be done
  only for clients of getCompilationDir(). This is as simple as checking
  for an empty string.

  The only current use of getCompilationDir is EmitGenDwarfInfo, which
  won't conceivably run with an invalid working dir. However, in the
  purely hypothetically and untestable case that this happens, the
  AT_comp_dir will be omitted from the compilation_unit DIE.

This should help fix assertions occurring with ports-mgmt/tinderbox,
when it is using jails, and sometimes invalidates clang's current
working directory.

Reported by:	decke

MFC 262809:

Pull in r203007 from upstream clang trunk:

  Don't produce an alias between destructors with different calling conventions.

  Fixes pr19007.

(Please note that is an LLVM PR identifier, not a FreeBSD one.)

This should fix Firefox and/or libxul crashes (due to problems with
regparm/stdcall calling conventions) on i386.

Reported by:	multiple users on freebsd-current
PR:		bin/187103

MFC 263048:

Repair recognition of "CC" as an alias for the C++ compiler, since it
was silently broken by upstream for a Windows-specific use-case.

Apparently some versions of CMake still rely on this archaic feature...

Reported by:	rakuco

MFC 263049:

Garbage collect the old way of adding the libstdc++ include directories
in clang's InitHeaderSearch.cpp.  This has been superseded by David
Chisnall's commit in r255321.

Moreover, if libc++ is used, the libstdc++ include directories should
not be in the search path at all.  These directories are now only used
if you pass -stdlib=libstdc++.

1 files changed, 96 insertions, 54 deletions

diff --git a/contrib/llvm/lib/Support/BlockFrequency.cpp b/contrib/llvm/lib/Support/BlockFrequency.cpp
index 84a993e..00efe90 100644
--- a/contrib/llvm/lib/Support/BlockFrequency.cpp
+++ b/contrib/llvm/lib/Support/BlockFrequency.cpp
@@ -18,76 +18,94 @@
 
 using namespace llvm;
 
-namespace {
-
-/// mult96bit - Multiply FREQ by N and store result in W array.
-void mult96bit(uint64_t freq, uint32_t N, uint64_t W[2]) {
+/// Multiply FREQ by N and store result in W array.
+static void mult96bit(uint64_t freq, uint32_t N, uint32_t W[3]) {
   uint64_t u0 = freq & UINT32_MAX;
   uint64_t u1 = freq >> 32;
 
-  // Represent 96-bit value as w[2]:w[1]:w[0];
-  uint32_t w[3] = { 0, 0, 0 };
-
+  // Represent 96-bit value as W[2]:W[1]:W[0];
   uint64_t t = u0 * N;
   uint64_t k = t >> 32;
-  w[0] = t;
+  W[0] = t;
   t = u1 * N + k;
-  w[1] = t;
-  w[2] = t >> 32;
-
-  // W[1] - higher bits.
-  // W[0] - lower bits.
-  W[0] = w[0] + ((uint64_t) w[1] << 32);
-  W[1] = w[2];
+  W[1] = t;
+  W[2] = t >> 32;
 }
 
-
-/// div96bit - Divide 96-bit value stored in W array by D. Return 64-bit frequency.
-uint64_t div96bit(uint64_t W[2], uint32_t D) {
-  uint64_t y = W[0];
-  uint64_t x = W[1];
-  int i;
-
-  for (i = 1; i <= 64 && x; ++i) {
-    uint32_t t = (int)x >> 31;
-    x = (x << 1) | (y >> 63);
-    y = y << 1;
-    if ((x | t) >= D) {
-      x -= D;
-      ++y;
+/// Divide 96-bit value stored in W[2]:W[1]:W[0] by D. Since our word size is a
+/// 32 bit unsigned integer, we can use a short division algorithm.
+static uint64_t divrem96bit(uint32_t W[3], uint32_t D, uint32_t *Rout) {
+  // We assume that W[2] is non-zero since if W[2] is not then the user should
+  // just use hardware division.
+  assert(W[2] && "This routine assumes that W[2] is non-zero since if W[2] is "
+         "zero, the caller should just use 64/32 hardware.");
+  uint32_t Q[3] = { 0, 0, 0 };
+
+  // The generalized short division algorithm sets i to m + n - 1, where n is
+  // the number of words in the divisior and m is the number of words by which
+  // the divident exceeds the divisor (i.e. m + n == the length of the dividend
+  // in words). Due to our assumption that W[2] is non-zero, we know that the
+  // dividend is of length 3 implying since n is 1 that m = 2. Thus we set i to
+  // m + n - 1 = 2 + 1 - 1 = 2.
+  uint32_t R = 0;
+  for (int i = 2; i >= 0; --i) {
+    uint64_t PartialD = uint64_t(R) << 32 | W[i];
+    if (PartialD == 0) {
+      Q[i] = 0;
+      R = 0;
+    } else if (PartialD < D) {
+      Q[i] = 0;
+      R = uint32_t(PartialD);
+    } else if (PartialD == D) {
+      Q[i] = 1;
+      R = 0;
+    } else {
+      Q[i] = uint32_t(PartialD / D);
+      R = uint32_t(PartialD - (Q[i] * D));
     }
   }
 
-  return y << (64 - i + 1);
-}
+  // If Q[2] is non-zero, then we overflowed.
+  uint64_t Result;
+  if (Q[2]) {
+    Result = UINT64_MAX;
+    R = D;
+  } else {
+    // Form the final uint64_t result, avoiding endianness issues.
+    Result = uint64_t(Q[0]) | (uint64_t(Q[1]) << 32);
+  }
+
+  if (Rout)
+    *Rout = R;
 
+  return Result;
 }
 
+uint32_t BlockFrequency::scale(uint32_t N, uint32_t D) {
+  assert(D != 0 && "Division by zero");
 
-BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) {
-  uint32_t n = Prob.getNumerator();
-  uint32_t d = Prob.getDenominator();
-
-  assert(n <= d && "Probability must be less or equal to 1.");
-
-  // Calculate Frequency * n.
-  uint64_t mulLo = (Frequency & UINT32_MAX) * n;
-  uint64_t mulHi = (Frequency >> 32) * n;
-  uint64_t mulRes = (mulHi << 32) + mulLo;
-
-  // If there was overflow use 96-bit operations.
-  if (mulHi > UINT32_MAX || mulRes < mulLo) {
-    // 96-bit value represented as W[1]:W[0].
-    uint64_t W[2];
-
-    // Probability is less or equal to 1 which means that results must fit
-    // 64-bit.
-    mult96bit(Frequency, n, W);
-    Frequency = div96bit(W, d);
-    return *this;
+  // Calculate Frequency * N.
+  uint64_t MulLo = (Frequency & UINT32_MAX) * N;
+  uint64_t MulHi = (Frequency >> 32) * N;
+  uint64_t MulRes = (MulHi << 32) + MulLo;
+
+  // If the product fits in 64 bits, just use built-in division.
+  if (MulHi <= UINT32_MAX && MulRes >= MulLo) {
+    Frequency = MulRes / D;
+    return MulRes % D;
   }
 
-  Frequency = mulRes / d;
+  // Product overflowed, use 96-bit operations.
+  // 96-bit value represented as W[2]:W[1]:W[0].
+  uint32_t W[3];
+  uint32_t R;
+  mult96bit(Frequency, N, W);
+  Frequency = divrem96bit(W, D, &R);
+  return R;
+}
+
+BlockFrequency &BlockFrequency::operator*=(const BranchProbability &Prob) {
+  scale(Prob.getNumerator(), Prob.getDenominator());
   return *this;
 }
 
@@ -98,6 +116,17 @@ BlockFrequency::operator*(const BranchProbability &Prob) const {
   return Freq;
 }
 
+BlockFrequency &BlockFrequency::operator/=(const BranchProbability &Prob) {
+  scale(Prob.getDenominator(), Prob.getNumerator());
+  return *this;
+}
+
+BlockFrequency BlockFrequency::operator/(const BranchProbability &Prob) const {
+  BlockFrequency Freq(Frequency);
+  Freq /= Prob;
+  return Freq;
+}
+
 BlockFrequency &BlockFrequency::operator+=(const BlockFrequency &Freq) {
   uint64_t Before = Freq.Frequency;
   Frequency += Freq.Frequency;
@@ -116,8 +145,21 @@ BlockFrequency::operator+(const BlockFrequency &Prob) const {
   return Freq;
 }
 
+uint32_t BlockFrequency::scale(const BranchProbability &Prob) {
+  return scale(Prob.getNumerator(), Prob.getDenominator());
+}
+
 void BlockFrequency::print(raw_ostream &OS) const {
-  OS << Frequency;
+  // Convert fixed-point number to decimal.
+  OS << Frequency / getEntryFrequency() << ".";
+  uint64_t Rem = Frequency % getEntryFrequency();
+  uint64_t Eps = 1;
+  do {
+    Rem *= 10;
+    Eps *= 10;
+    OS << Rem / getEntryFrequency();
+    Rem = Rem % getEntryFrequency();
+  } while (Rem >= Eps/2);
 }
 
 namespace llvm {