Merge from 'main' to 'sycl-web' (#8)

  CONFLICT (content): Merge conflict in clang/lib/Frontend/CompilerInvocation.cpp

Author: AlexeySachkov

clang/lib/Frontend/CompilerInvocation.cpp

@@ -2205,12 +2205,6 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
     }
   }
 
-  if (const Arg *A = Args.getLastArg(OPT_fcf_protection_EQ)) {
-    StringRef Name = A->getValue();
-    if (Name == "full" || Name == "branch") {
-      Opts.CFProtectionBranch = 1;
-    }
-  }
   // -cl-std only applies for OpenCL language standards.
   // Override the -std option in this case.
   if (const Arg *A = Args.getLastArg(OPT_cl_std_EQ)) {
@@ -2233,7 +2227,6 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
       LangStd = OpenCLLangStd;
   }
 
-  Opts.SYCLIsDevice = Opts.SYCL && Args.hasArg(options::OPT_fsycl_is_device);
   if (Opts.SYCL) {
     Opts.SYCLIsDevice = Args.hasArg(options::OPT_fsycl_is_device);
     Opts.SYCLIsHost = Args.hasArg(options::OPT_fsycl_is_host);
@@ -2276,6 +2269,15 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
 
   CompilerInvocation::setLangDefaults(Opts, IK, T, Includes, LangStd);
 
+  if (const Arg *A = Args.getLastArg(OPT_fcf_protection_EQ)) {
+    StringRef Name = A->getValue();
+    if (Name == "full" || Name == "branch") {
+      Opts.CFProtectionBranch = 1;
+    }
+  }
+
+  Opts.SYCLIsDevice = Opts.SYCL && Args.hasArg(options::OPT_fsycl_is_device);
+
   // -cl-strict-aliasing needs to emit diagnostic in the case where CL > 1.0.
   // This option should be deprecated for CL > 1.0 because
   // this option was added for compatibility with OpenCL 1.0.
@@ -3014,6 +3016,7 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
     // PIClevel and PIELevel are needed during code generation and this should be
     // set regardless of the input type.
     LangOpts.PICLevel = getLastArgIntValue(Args, OPT_pic_level, 0, Diags);
+    LangOpts.PIE = Args.hasArg(OPT_pic_is_pie);
     parseSanitizerKinds("-fsanitize=", Args.getAllArgValues(OPT_fsanitize_EQ),
                         Diags, LangOpts.Sanitize);
   } else {

libc/src/string/memory_utils/memcpy_utils.h

@@ -72,28 +72,35 @@ static void CopyBlockOverlap(char *__restrict dst, const char *__restrict src,
 
 // Copies `count` bytes by blocks of `kBlockSize` bytes.
 // Copies at the start and end of the buffer are unaligned.
-// Copies in the middle of the buffer are aligned to `kBlockSize`.
+// Copies in the middle of the buffer are aligned to `kAlignment`.
 //
 // e.g. with
 // [12345678123456781234567812345678]
-// [__XXXXXXXXXXXXXXXXXXXXXXXXXXX___]
-// [__XXXXXXXX______________________]
-// [________XXXXXXXX________________]
-// [________________XXXXXXXX________]
-// [_____________________XXXXXXXX___]
+// [__XXXXXXXXXXXXXXXXXXXXXXXXXXXX___]
+// [__XXXX___________________________]
+// [_____XXXXXXXX____________________]
+// [_____________XXXXXXXX____________]
+// [_____________________XXXXXXXX____]
+// [______________________XXXXXXXX___]
 //
-// Precondition: `count > 2 * kBlockSize` for efficiency.
-//               `count >= kBlockSize` for correctness.
-template <size_t kBlockSize>
+// Precondition: `kAlignment <= kBlockSize`
+//               `count > 2 * kBlockSize` for efficiency.
+//               `count >= kAlignment` for correctness.
+template <size_t kBlockSize, size_t kAlignment = kBlockSize>
 static void CopyAlignedBlocks(char *__restrict dst, const char *__restrict src,
                               size_t count) {
-  CopyBlock<kBlockSize>(dst, src); // Copy first block
+  static_assert(is_power2(kAlignment), "kAlignment must be a power of two");
+  static_assert(is_power2(kBlockSize), "kBlockSize must be a power of two");
+  static_assert(kAlignment <= kBlockSize,
+                "kAlignment must be less or equal to block size");
+  CopyBlock<kAlignment>(dst, src); // Copy first block
 
   // Copy aligned blocks
-  const size_t ofla = offset_from_last_aligned<kBlockSize>(src);
+  const size_t ofla = offset_from_last_aligned<kAlignment>(src);
   const size_t limit = count + ofla - kBlockSize;
-  for (size_t offset = kBlockSize; offset < limit; offset += kBlockSize)
-    CopyBlock<kBlockSize>(dst - ofla + offset, src - ofla + offset);
+  for (size_t offset = kAlignment; offset < limit; offset += kBlockSize)
+    CopyBlock<kBlockSize>(dst - ofla + offset,
+                          assume_aligned<kAlignment>(src - ofla + offset));
 
   CopyLastBlock<kBlockSize>(dst, src, count); // Copy last block
 }

libc/src/string/memory_utils/utils.h

@@ -60,6 +60,10 @@ static inline intptr_t offset_to_next_cache_line(const void *ptr) {
   return offset_to_next_aligned<LLVM_LIBC_CACHELINE_SIZE>(ptr);
 }
 
+template <size_t alignment, typename T> static T *assume_aligned(T *ptr) {
+  return reinterpret_cast<T *>(__builtin_assume_aligned(ptr, alignment));
+}
+
 } // namespace __llvm_libc
 
 #endif // LLVM_LIBC_SRC_MEMORY_UTILS_H

libc/test/src/string/memory_utils/memcpy_utils_test.cpp

@@ -211,7 +211,24 @@ TEST(MemcpyUtilsTest, CopyAlignedBlocks) {
   EXPECT_STREQ(trace.Read(), "011121111111");
 }
 
-TEST(MemcpyUtilsTest, MaxReloads) {
+TEST(MemcpyUtilsTest, CopyAlignedBlocksWithAlignment) {
+  auto &trace = GetTrace();
+  // Source is aligned and multiple of alignment.
+  //   "11111111"
+  trace.Clear();
+  CopyAlignedBlocks<8, 4>(I(0), I(0), 8);
+  EXPECT_STREQ(trace.Write(), "22221111");
+  EXPECT_STREQ(trace.Read(), "22221111");
+
+  // Source is aligned and multiple of alignment.
+  //   "111111111"
+  trace.Clear();
+  CopyAlignedBlocks<8, 4>(I(0), I(0), 9);
+  EXPECT_STREQ(trace.Write(), "122211111");
+  EXPECT_STREQ(trace.Read(), "122211111");
+}
+
+TEST(MemcpyUtilsTest, CopyAlignedBlocksMaxReloads) {
   auto &trace = GetTrace();
   for (size_t alignment = 0; alignment < 32; ++alignment) {
     for (size_t count = 64; count < 768; ++count) {
@@ -231,4 +248,24 @@ TEST(MemcpyUtilsTest, MaxReloads) {
   }
 }
 
+TEST(MemcpyUtilsTest, CopyAlignedBlocksWithAlignmentMaxReloads) {
+  auto &trace = GetTrace();
+  for (size_t alignment = 0; alignment < 32; ++alignment) {
+    for (size_t count = 64; count < 768; ++count) {
+      trace.Clear();
+      // We should never reload more than twice when copying from count = 2x32.
+      CopyAlignedBlocks<32, 16>(I(alignment), I(0), count);
+      const char *const written = trace.Write();
+      // First bytes are untouched.
+      for (size_t i = 0; i < alignment; ++i)
+        EXPECT_EQ(written[i], '0');
+      // Next bytes are loaded once or twice but no more.
+      for (size_t i = alignment; i < count; ++i) {
+        EXPECT_GE(written[i], '1');
+        EXPECT_LE(written[i], '2');
+      }
+    }
+  }
+}
+
 } // namespace __llvm_libc

llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

@@ -20887,6 +20887,32 @@ SDValue DAGCombiner::visitVECTOR_SHUFFLE(SDNode *N) {
         continue;
       }
 
+      // Last chance - see if the vector is another shuffle and if it
+      // uses one of the existing candidate shuffle ops.
+      if (auto *CurrentSVN = dyn_cast<ShuffleVectorSDNode>(CurrentVec)) {
+        int InnerIdx = CurrentSVN->getMaskElt(Idx);
+        if (InnerIdx < 0) {
+          Mask.push_back(-1);
+          continue;
+        }
+        SDValue InnerVec = (InnerIdx < (int)NumElts)
+                               ? CurrentSVN->getOperand(0)
+                               : CurrentSVN->getOperand(1);
+        if (InnerVec.isUndef()) {
+          Mask.push_back(-1);
+          continue;
+        }
+        InnerIdx %= NumElts;
+        if (InnerVec == SV0) {
+          Mask.push_back(InnerIdx);
+          continue;
+        }
+        if (InnerVec == SV1) {
+          Mask.push_back(InnerIdx + NumElts);
+          continue;
+        }
+      }
+
       // Bail out if we cannot convert the shuffle pair into a single shuffle.
       return false;
     }

llvm/lib/Transforms/Scalar/LoopSink.cpp

@@ -70,7 +70,7 @@ static cl::opt<unsigned> MaxNumberOfUseBBsForSinking(
     cl::desc("Do not sink instructions that have too many uses."));
 
 static cl::opt<bool> EnableMSSAInLoopSink(
-    "enable-mssa-in-loop-sink", cl::Hidden, cl::init(false),
+    "enable-mssa-in-loop-sink", cl::Hidden, cl::init(true),
     cl::desc("Enable MemorySSA for LoopSink in new pass manager"));
 
 static cl::opt<bool> EnableMSSAInLegacyLoopSink(