[CI-NOTIFY]: TCWG Bisect tcwg_bmk_tk1/llvm-master-arm-spec2k6-O2 - Build # 8 - Successful! - linaro-toolchain

10 Jul 2021

Successfully identified regression in *llvm* in CI configuration tcwg_bmk_llvm_tk1/llvm-master-arm-spec2k6-O2.  So far, this commit has regressed CI configurations:
 - tcwg_bmk_llvm_tk1/llvm-master-arm-spec2k6-O2
Culprit:
<cut>
commit 87065c0d242d955e6f3fddf5cbc790d025c3521c
Author: Guillaume Chatelet gchatelet@google.com
Date:   Wed Jun 23 14:19:40 2021 +0000
[libc] add benchmarks for memcmp and bzero
Differential Revision: https://reviews.llvm.org/D104511
</cut>
Results regressed to (for first_bad == 87065c0d242d955e6f3fddf5cbc790d025c3521c)
# reset_artifacts:
-10
# build_abe binutils:
-9
# build_abe stage1 -- --set gcc_override_configure=--with-mode=arm --set gcc_override_configure=--disable-libsanitizer:
-8
# build_abe linux:
-7
# build_abe glibc:
-6
# build_abe stage2 -- --set gcc_override_configure=--with-mode=arm --set gcc_override_configure=--disable-libsanitizer:
-5
# build_llvm true:
-3
# true:
0
# benchmark -O2_marm -- artifacts/build-87065c0d242d955e6f3fddf5cbc790d025c3521c/results_id:
1
# 400.perlbench,perlbench_base.default                          regressed by 103
from (for last_good == c125af82a5ff5dbbbcb8ebc5cde156d41e6ac281)
# reset_artifacts:
-10
# build_abe binutils:
-9
# build_abe stage1 -- --set gcc_override_configure=--with-mode=arm --set gcc_override_configure=--disable-libsanitizer:
-8
# build_abe linux:
-7
# build_abe glibc:
-6
# build_abe stage2 -- --set gcc_override_configure=--with-mode=arm --set gcc_override_configure=--disable-libsanitizer:
-5
# build_llvm true:
-3
# true:
0
# benchmark -O2_marm -- artifacts/build-c125af82a5ff5dbbbcb8ebc5cde156d41e6ac281/results_id:
1
Artifacts of last_good build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a...
Results ID of last_good: tk1_32/tcwg_bmk_llvm_tk1/bisect-llvm-master-arm-spec2k6-O2/1292
Artifacts of first_bad build: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a...
Results ID of first_bad: tk1_32/tcwg_bmk_llvm_tk1/bisect-llvm-master-arm-spec2k6-O2/1297
Build top page/logs: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a...
Configuration details:
Reproduce builds:
<cut>
mkdir investigate-llvm-87065c0d242d955e6f3fddf5cbc790d025c3521c
cd investigate-llvm-87065c0d242d955e6f3fddf5cbc790d025c3521c
git clone https://git.linaro.org/toolchain/jenkins-scripts
mkdir -p artifacts/manifests
curl -o artifacts/manifests/build-baseline.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a... --fail
curl -o artifacts/manifests/build-parameters.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a... --fail
curl -o artifacts/test.sh https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a... --fail
chmod +x artifacts/test.sh
# Reproduce the baseline build (build all pre-requisites)
./jenkins-scripts/tcwg_bmk-build.sh @@ artifacts/manifests/build-baseline.sh
cd llvm
# Reproduce first_bad build
git checkout --detach 87065c0d242d955e6f3fddf5cbc790d025c3521c
../artifacts/test.sh
# Reproduce last_good build
git checkout --detach c125af82a5ff5dbbbcb8ebc5cde156d41e6ac281
../artifacts/test.sh
cd ..
</cut>
History of pending regressions and results: https://git.linaro.org/toolchain/ci/base-artifacts.git/log/?h=linaro-local/c...
Artifacts: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a...
Build log: https://ci.linaro.org/job/tcwg_bmk_ci_llvm-bisect-tcwg_bmk_tk1-llvm-master-a...
Full commit (up to 1000 lines):
<cut>
commit 87065c0d242d955e6f3fddf5cbc790d025c3521c
Author: Guillaume Chatelet gchatelet@google.com
Date:   Wed Jun 23 14:19:40 2021 +0000
[libc] add benchmarks for memcmp and bzero
Differential Revision: https://reviews.llvm.org/D104511
---
 libc/benchmarks/CMakeLists.txt              |  2 ++
 libc/benchmarks/LibcMemoryBenchmarkMain.cpp | 47 +++++++++++++++++++++++++++--
 libc/src/string/CMakeLists.txt              | 38 +++++++++++++++++------
 3 files changed, 75 insertions(+), 12 deletions(-)

diff --git a/libc/benchmarks/CMakeLists.txt b/libc/benchmarks/CMakeLists.txt
index feff80cf4501..390b802bd8f7 100644
--- a/libc/benchmarks/CMakeLists.txt
+++ b/libc/benchmarks/CMakeLists.txt
@@ -169,3 +169,5 @@ endfunction()
add_libc_multi_impl_benchmark(memcpy)
 add_libc_multi_impl_benchmark(memset)
+add_libc_multi_impl_benchmark(bzero)
+add_libc_multi_impl_benchmark(memcmp)
diff --git a/libc/benchmarks/LibcMemoryBenchmarkMain.cpp b/libc/benchmarks/LibcMemoryBenchmarkMain.cpp
index e3d455423de2..6fa01ede52e3 100644
--- a/libc/benchmarks/LibcMemoryBenchmarkMain.cpp
+++ b/libc/benchmarks/LibcMemoryBenchmarkMain.cpp
@@ -17,10 +17,14 @@
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
+#include <cstring>
+
 namespace __llvm_libc {
extern void *memcpy(void *__restrict, const void *__restrict, size_t);
 extern void *memset(void *, int, size_t);
+extern void bzero(void *, size_t);
+extern int memcmp(const void *, const void *, size_t);
} // namespace __llvm_libc
@@ -79,7 +83,7 @@ struct Benchmark {
     return [this](ParameterType P) {
       __llvm_libc::memcpy(DstBuffer + P.OffsetBytes, SrcBuffer + P.OffsetBytes,
                           P.SizeBytes);
-      return DstBuffer + P.OffsetBytes;
+      return DstBuffer[P.OffsetBytes];
     };
   }
@@ -97,18 +101,55 @@ struct Benchmark {
     return [this](ParameterType P) {
       __llvm_libc::memset(DstBuffer + P.OffsetBytes, P.OffsetBytes & 0xFF,
                           P.SizeBytes);
-      return DstBuffer + P.OffsetBytes;
+      return DstBuffer[P.OffsetBytes];
+    };
+  }
+
+  AlignedBuffer DstBuffer;
+};
+#elif defined(LIBC_BENCHMARK_FUNCTION_BZERO)
+struct Benchmark {
+  static constexpr auto GetDistributions = &getMemsetSizeDistributions;
+  static constexpr size_t BufferCount = 1;
+
+  Benchmark(const size_t BufferSize) : DstBuffer(BufferSize) {}
+
+  inline auto functor() {
+    return [this](ParameterType P) {
+      __llvm_libc::bzero(DstBuffer + P.OffsetBytes, P.SizeBytes);
+      return DstBuffer[P.OffsetBytes];
     };
   }
AlignedBuffer DstBuffer;
 };
+#elif defined(LIBC_BENCHMARK_FUNCTION_MEMCMP)
+struct Benchmark {
+  static constexpr auto GetDistributions = &getMemcmpSizeDistributions;
+  static constexpr size_t BufferCount = 2;
+
+  Benchmark(const size_t BufferSize)
+      : BufferA(BufferSize), BufferB(BufferSize) {
+    // The memcmp buffers always compare equal.
+    memset(BufferA.begin(), 0xF, BufferSize);
+    memset(BufferB.begin(), 0xF, BufferSize);
+  }
+
+  inline auto functor() {
+    return [this](ParameterType P) {
+      return __llvm_libc::memcmp(BufferA + P.OffsetBytes,
+                                 BufferB + P.OffsetBytes, P.SizeBytes);
+    };
+  }
+
+  AlignedBuffer BufferA;
+  AlignedBuffer BufferB;
+};
 #else
 #error "Missing LIBC_BENCHMARK_FUNCTION_XXX definition"
 #endif
struct Harness : Benchmark {
-
   Harness(const size_t BufferSize, size_t BatchParameterCount,
           std::function<unsigned()> SizeSampler,
           std::function<unsigned()> OffsetSampler)
diff --git a/libc/src/string/CMakeLists.txt b/libc/src/string/CMakeLists.txt
index 4dd8ee0bf4a2..97ac99cb89fe 100644
--- a/libc/src/string/CMakeLists.txt
+++ b/libc/src/string/CMakeLists.txt
@@ -58,14 +58,6 @@ add_entrypoint_object(
     .string_utils
 )
-add_entrypoint_object(
-  memcmp
-  SRCS
-    memcmp.cpp
-  HDRS
-    memcmp.h
-)
-
 add_entrypoint_object(
   memmove
   SRCS
@@ -280,7 +272,6 @@ function(add_bzero bzero_name)
       .memory_utils.memory_utils
       libc.include.string
     COMPILE_OPTIONS
-      -fno-builtin-memset
       -fno-builtin-bzero
     ${ARGN}
   )
@@ -297,3 +288,32 @@ else()
   add_bzero(bzero_opt_host          COMPILE_OPTIONS ${LIBC_COMPILE_OPTIONS_NATIVE})
   add_bzero(bzero)
 endif()
+
+# ------------------------------------------------------------------------------
+# memcmp
+# ------------------------------------------------------------------------------
+
+function(add_memcmp memcmp_name)
+  add_implementation(memcmp ${memcmp_name}
+    SRCS ${LIBC_SOURCE_DIR}/src/string/memcmp.cpp
+    HDRS ${LIBC_SOURCE_DIR}/src/string/memcmp.h
+    DEPENDS
+      .memory_utils.memory_utils
+      libc.include.string
+    COMPILE_OPTIONS
+      -fno-builtin-memcmp
+    ${ARGN}
+  )
+endfunction()
+
+if(${LIBC_TARGET_ARCHITECTURE_IS_X86})
+  add_memcmp(memcmp_x86_64_opt_sse2   COMPILE_OPTIONS -march=k8             REQUIRE SSE2)
+  add_memcmp(memcmp_x86_64_opt_sse4   COMPILE_OPTIONS -march=nehalem        REQUIRE SSE4_2)
+  add_memcmp(memcmp_x86_64_opt_avx2   COMPILE_OPTIONS -march=haswell        REQUIRE AVX2)
+  add_memcmp(memcmp_x86_64_opt_avx512 COMPILE_OPTIONS -march=skylake-avx512 REQUIRE AVX512F)
+  add_memcmp(memcmp_opt_host          COMPILE_OPTIONS ${LIBC_COMPILE_OPTIONS_NATIVE})
+  add_memcmp(memcmp)
+else()
+  add_memcmp(memcmp_opt_host          COMPILE_OPTIONS ${LIBC_COMPILE_OPTIONS_NATIVE})
+  add_memcmp(memcmp)
+endif()
</cut>

    