[libc] NVPTX Profiling (#92009)

PR for adding microbenchmarking infrastructure for NVPTX. `nvlink`
cannot perform LTO, so we cannot inline `libc` functions and this
function call overhead is not adjusted for during microbenchmarking.

1 files changed, 19 insertions, 8 deletions

diff --git a/libc/cmake/modules/LLVMLibCTestRules.cmake b/libc/cmake/modules/LLVMLibCTestRules.cmake
index c8d7c8a..fbeec32 100644
--- a/libc/cmake/modules/LLVMLibCTestRules.cmake
+++ b/libc/cmake/modules/LLVMLibCTestRules.cmake
@@ -526,12 +526,15 @@ function(add_integration_test test_name)
   add_dependencies(${INTEGRATION_TEST_SUITE} ${fq_target_name})
 endfunction(add_integration_test)
 
-# Rule to add a hermetic test. A hermetic test is one whose executable is fully
+# Rule to add a hermetic program. A hermetic program is one whose executable is fully
 # statically linked and consists of pieces drawn only from LLVM's libc. Nothing,
 # including the startup objects, come from the system libc.
 #
+# For the GPU, these can be either tests or benchmarks, depending on the value
+# of the LINK_LIBRARIES arg.
+#
 # Usage:
-#   add_libc_hermetic_test(
+#   add_libc_hermetic(
 #     <target name>
 #     SUITE <the suite to which the test should belong>
 #     SRCS <src1.cpp> [src2.cpp ...]
@@ -543,14 +546,14 @@ endfunction(add_integration_test)
 #     LINK_LIBRARIES <list of linking libraries for this target>
 #     LOADER_ARGS <list of special args to loaders (like the GPU loader)>
 #   )
-function(add_libc_hermetic_test test_name)
+function(add_libc_hermetic test_name)
   if(NOT TARGET libc.startup.${LIBC_TARGET_OS}.crt1)
     message(VERBOSE "Skipping ${fq_target_name} as it is not available on ${LIBC_TARGET_OS}.")
     return()
   endif()
   cmake_parse_arguments(
     "HERMETIC_TEST"
-    "" # No optional arguments
+    "IS_BENCHMARK" # Optional arguments
     "SUITE" # Single value arguments
     "SRCS;HDRS;DEPENDS;ARGS;ENV;COMPILE_OPTIONS;LINK_LIBRARIES;LOADER_ARGS" # Multi-value arguments
     ${ARGN}
@@ -678,7 +681,6 @@ function(add_libc_hermetic_test test_name)
     PRIVATE
       libc.startup.${LIBC_TARGET_OS}.crt1${internal_suffix}
       ${link_libraries}
-      LibcTest.hermetic
       LibcHermeticTestSupport.hermetic
       # The NVIDIA 'nvlink' linker does not currently support static libraries.
       $<$<NOT:$<BOOL:${LIBC_TARGET_ARCHITECTURE_IS_NVPTX}>>:${fq_target_name}.__libc__>)
@@ -714,8 +716,12 @@ function(add_libc_hermetic_test test_name)
   )
 
   add_dependencies(${HERMETIC_TEST_SUITE} ${fq_target_name})
-  add_dependencies(libc-hermetic-tests ${fq_target_name})
-endfunction(add_libc_hermetic_test)
+  if(NOT ${HERMETIC_TEST_IS_BENCHMARK})
+    # If it is a benchmark, it will already have been added to the
+    # gpu-benchmark target
+    add_dependencies(libc-hermetic-tests ${fq_target_name})
+  endif()
+endfunction(add_libc_hermetic)
 
 # A convenience function to add both a unit test as well as a hermetic test.
 function(add_libc_test test_name)
@@ -730,7 +736,12 @@ function(add_libc_test test_name)
     add_libc_unittest(${test_name}.__unit__ ${LIBC_TEST_UNPARSED_ARGUMENTS})
   endif()
   if(LIBC_ENABLE_HERMETIC_TESTS AND NOT LIBC_TEST_UNIT_TEST_ONLY)
-    add_libc_hermetic_test(${test_name}.__hermetic__ ${LIBC_TEST_UNPARSED_ARGUMENTS})
+    add_libc_hermetic(
+      ${test_name}.__hermetic__
+      LINK_LIBRARIES
+        LibcTest.hermetic
+      ${LIBC_TEST_UNPARSED_ARGUMENTS}
+    )
     get_fq_target_name(${test_name} fq_test_name)
     if(TARGET ${fq_test_name}.__hermetic__ AND TARGET ${fq_test_name}.__unit__)
       # Tests like the file tests perform file operations on disk file. If we