[all-commits] [llvm/llvm-project] e2d0b4: [DFSan] Add efficient fast16labels instrumentation...

[Matt Morehouse via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: e2d0b44a7cd261218c9e527d23eb5d13425afe8b
      https://github.com/llvm/llvm-project/commit/e2d0b44a7cd261218c9e527d23eb5d13425afe8b
  Author: Matt Morehouse <mascasa at google.com>
  Date:   2020-07-29 (Wed, 29 Jul 2020)

  Changed paths:
    M clang/docs/DataFlowSanitizer.rst
    M compiler-rt/lib/dfsan/dfsan.cpp
    M compiler-rt/lib/dfsan/dfsan_flags.inc
    M compiler-rt/lib/dfsan/done_abilist.txt
    M compiler-rt/lib/fuzzer/FuzzerDataFlowTrace.cpp
    M compiler-rt/lib/fuzzer/dataflow/DataFlow.cpp
    M compiler-rt/test/dfsan/fast16labels.c
    M compiler-rt/test/fuzzer/dataflow.test
    M compiler-rt/test/fuzzer/only-some-bytes-fork.test
    M compiler-rt/test/fuzzer/only-some-bytes.test
    M llvm/lib/Transforms/Instrumentation/DataFlowSanitizer.cpp
    A llvm/test/Instrumentation/DataFlowSanitizer/fast16labels.ll

  Log Message:
  -----------
  [DFSan] Add efficient fast16labels instrumentation mode.

Adds the -fast-16-labels flag, which enables efficient instrumentation
for DFSan when the user needs <=16 labels.  The instrumentation
eliminates most branches and most calls to __dfsan_union or
__dfsan_union_load.

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D84371