[Openmp-commits] [openmp] 5f864ba - Revert "[OpenMP] Use simple VLA implementation to replace uses of actual VLA"

[Shilei Tian via Openmp-commits]

Author: Shilei Tian
Date: 2023-11-30T16:15:54-05:00
New Revision: 5f864ba1957e42283b9680ee47811d12e69d92bd

URL: https://github.com/llvm/llvm-project/commit/5f864ba1957e42283b9680ee47811d12e69d92bd
DIFF: https://github.com/llvm/llvm-project/commit/5f864ba1957e42283b9680ee47811d12e69d92bd.diff

LOG: Revert "[OpenMP] Use simple VLA implementation to replace uses of actual VLA"

This reverts commit 97e16da450e94c92456fa5a74768ec1b22fe6b63 because it
causes build error on i386 system.

Added: 
    

Modified: 
    openmp/runtime/src/kmp_gsupport.cpp
    openmp/runtime/src/kmp_runtime.cpp

Removed: 
    openmp/runtime/src/kmp_utils.h


################################################################################
diff  --git a/openmp/runtime/src/kmp_gsupport.cpp b/openmp/runtime/src/kmp_gsupport.cpp
index f38a0ddfc62a1fb..d77d4809a7e95c2 100644
--- a/openmp/runtime/src/kmp_gsupport.cpp
+++ b/openmp/runtime/src/kmp_gsupport.cpp
@@ -12,7 +12,6 @@
 
 #include "kmp.h"
 #include "kmp_atomic.h"
-#include "kmp_utils.h"
 
 #if OMPT_SUPPORT
 #include "ompt-specific.h"
@@ -1281,7 +1280,7 @@ void KMP_EXPAND_NAME(KMP_API_NAME_GOMP_TASK)(void (*func)(void *), void *data,
       KMP_ASSERT(depend);
       kmp_gomp_depends_info_t gomp_depends(depend);
       kmp_int32 ndeps = gomp_depends.get_num_deps();
-      SimpleVLA<kmp_depend_info_t> dep_list(ndeps);
+      kmp_depend_info_t dep_list[ndeps];
       for (kmp_int32 i = 0; i < ndeps; i++)
         dep_list[i] = gomp_depends.get_kmp_depend(i);
       kmp_int32 ndeps_cnv;
@@ -1310,7 +1309,7 @@ void KMP_EXPAND_NAME(KMP_API_NAME_GOMP_TASK)(void (*func)(void *), void *data,
       KMP_ASSERT(depend);
       kmp_gomp_depends_info_t gomp_depends(depend);
       kmp_int32 ndeps = gomp_depends.get_num_deps();
-      SimpleVLA<kmp_depend_info_t> dep_list(ndeps);
+      kmp_depend_info_t dep_list[ndeps];
       for (kmp_int32 i = 0; i < ndeps; i++)
         dep_list[i] = gomp_depends.get_kmp_depend(i);
       __kmpc_omp_wait_deps(&loc, gtid, ndeps, dep_list, 0, NULL);
@@ -1994,7 +1993,7 @@ void KMP_EXPAND_NAME(KMP_API_NAME_GOMP_TASKWAIT_DEPEND)(void **depend) {
   KA_TRACE(20, ("GOMP_taskwait_depend: T#%d\n", gtid));
   kmp_gomp_depends_info_t gomp_depends(depend);
   kmp_int32 ndeps = gomp_depends.get_num_deps();
-  SimpleVLA<kmp_depend_info_t> dep_list(ndeps);
+  kmp_depend_info_t dep_list[ndeps];
   for (kmp_int32 i = 0; i < ndeps; i++)
     dep_list[i] = gomp_depends.get_kmp_depend(i);
 #if OMPT_SUPPORT

diff  --git a/openmp/runtime/src/kmp_runtime.cpp b/openmp/runtime/src/kmp_runtime.cpp
index 4ac694ace874220..25136691bc72de9 100644
--- a/openmp/runtime/src/kmp_runtime.cpp
+++ b/openmp/runtime/src/kmp_runtime.cpp
@@ -24,7 +24,6 @@
 #include "kmp_wait_release.h"
 #include "kmp_wrapper_getpid.h"
 #include "kmp_dispatch.h"
-#include "kmp_utils.h"
 #if KMP_USE_HIER_SCHED
 #include "kmp_dispatch_hier.h"
 #endif
@@ -1653,7 +1652,7 @@ __kmp_serial_fork_call(ident_t *loc, int gtid, enum fork_context_e call_context,
 /* josh todo: hypothetical question: what do we do for OS X*? */
 #if KMP_OS_LINUX &&                                                            \
     (KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM || KMP_ARCH_AARCH64)
-  SimpleVLA<void *> args(argc);
+  void *args[argc];
 #else
   void **args = (void **)KMP_ALLOCA(argc * sizeof(void *));
 #endif /* KMP_OS_LINUX && ( KMP_ARCH_X86 || KMP_ARCH_X86_64 || KMP_ARCH_ARM || \

diff  --git a/openmp/runtime/src/kmp_utils.h b/openmp/runtime/src/kmp_utils.h
deleted file mode 100644
index 009334792c45218..000000000000000
--- a/openmp/runtime/src/kmp_utils.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * kmp_utils.h -- Utilities that used internally
- */
-
-//===----------------------------------------------------------------------===//
-//
-// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
-// See https://llvm.org/LICENSE.txt for license information.
-// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
-//
-//===----------------------------------------------------------------------===//
-#ifndef __KMP_UTILS_H__
-#define __KMP_UTILS_H__
-
-#include <cstddef>
-
-#include "kmp.h"
-
-/// A simple pure header implementation of VLA that aims to replace uses of
-/// actual VLA, which can cause compile warning. This class by default creates a
-/// stack buffer that can accomodate \p N elements. If the number of elements is
-/// greater than \p N, then a heap buffer will be allocated and used to
-/// accomodate the elements. Similar to the actual VLA, we don't check boundary
-/// (for now), so we will not store the number of elements. We can always revise
-/// it later.
-template <typename T, unsigned N = 8> class SimpleVLA final {
-  T StackBuffer[N];
-  T *HeapBuffer = nullptr;
-  T *Ptr = StackBuffer;
-
-public:
-  SimpleVLA() = delete;
-  SimpleVLA(const SimpleVLA &) = delete;
-  SimpleVLA(SimpleVLA &&) = delete;
-  SimpleVLA &operator=(const SimpleVLA &) = delete;
-  SimpleVLA &operator=(SimpleVLA &&) = delete;
-
-  explicit SimpleVLA(unsigned NumOfElements) noexcept {
-    if (NumOfElements > N) {
-      HeapBuffer =
-          reinterpret_cast<T *>(__kmp_allocate(NumOfElements * sizeof(T)));
-      Ptr = HeapBuffer;
-    }
-  }
-
-  ~SimpleVLA() {
-    if (HeapBuffer)
-      __kmp_free(HeapBuffer);
-  }
-
-  const T &operator[](std::size_t Idx) const noexcept { return Ptr[Idx]; }
-  T &operator[](std::size_t Idx) noexcept { return Ptr[Idx]; }
-
-  operator T *() noexcept { return Ptr; }
-  operator const T *() const noexcept { return Ptr; }
-};
-
-#endif