[libc-commits] [libc] bf42a78 - [libc] Implement placeholder memory functions on the GPU (#101082)
via libc-commits
libc-commits at lists.llvm.org
Tue Jul 30 08:15:35 PDT 2024
Author: Joseph Huber
Date: 2024-07-30T10:15:30-05:00
New Revision: bf42a7860a208439a0a29f5dcc7a33949c484efb
URL: https://github.com/llvm/llvm-project/commit/bf42a7860a208439a0a29f5dcc7a33949c484efb
DIFF: https://github.com/llvm/llvm-project/commit/bf42a7860a208439a0a29f5dcc7a33949c484efb.diff
LOG: [libc] Implement placeholder memory functions on the GPU (#101082)
Summary:
These functions are needed for `libc++` to link successfully. We can't
implement them well currently, so simply provide some stand-in
implementations. `realloc` will currently copy garbage and potentially
fault and `aligned_alloc` will work unless your alignment is more than
4K alignment. However, these should work in practice to get tests
running. I will write a real allocator soon™.
Added:
libc/src/stdlib/gpu/aligned_alloc.cpp
libc/src/stdlib/gpu/calloc.cpp
libc/src/stdlib/gpu/realloc.cpp
Modified:
libc/config/gpu/entrypoints.txt
libc/src/stdlib/CMakeLists.txt
libc/src/stdlib/gpu/CMakeLists.txt
Removed:
################################################################################
diff --git a/libc/config/gpu/entrypoints.txt b/libc/config/gpu/entrypoints.txt
index 157f6f8af00a9..04a42c3019495 100644
--- a/libc/config/gpu/entrypoints.txt
+++ b/libc/config/gpu/entrypoints.txt
@@ -166,8 +166,9 @@ set(TARGET_LIBC_ENTRYPOINTS
libc.src.stdlib.strtoul
libc.src.stdlib.strtoull
- # Only implemented in the test suite
+ # TODO: Implement these correctly
libc.src.stdlib.aligned_alloc
+ libc.src.stdlib.calloc
libc.src.stdlib.free
libc.src.stdlib.malloc
libc.src.stdlib.realloc
diff --git a/libc/src/stdlib/CMakeLists.txt b/libc/src/stdlib/CMakeLists.txt
index d79acb390ff91..0f363eecc6251 100644
--- a/libc/src/stdlib/CMakeLists.txt
+++ b/libc/src/stdlib/CMakeLists.txt
@@ -443,14 +443,23 @@ if(LIBC_TARGET_OS_IS_GPU)
DEPENDS
.${LIBC_TARGET_OS}.free
)
- add_entrypoint_external(
- calloc
- )
- add_entrypoint_external(
+ add_entrypoint_object(
realloc
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.realloc
)
- add_entrypoint_external(
+ add_entrypoint_object(
+ calloc
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.calloc
+ )
+ add_entrypoint_object(
aligned_alloc
+ ALIAS
+ DEPENDS
+ .${LIBC_TARGET_OS}.aligned_alloc
)
endif()
diff --git a/libc/src/stdlib/gpu/CMakeLists.txt b/libc/src/stdlib/gpu/CMakeLists.txt
index f8a11ec3ffb00..073f81515870b 100644
--- a/libc/src/stdlib/gpu/CMakeLists.txt
+++ b/libc/src/stdlib/gpu/CMakeLists.txt
@@ -20,6 +20,39 @@ add_entrypoint_object(
libc.src.__support.RPC.rpc_client
)
+add_entrypoint_object(
+ realloc
+ SRCS
+ realloc.cpp
+ HDRS
+ ../realloc.h
+ DEPENDS
+ libc.include.stdlib
+ libc.src.__support.GPU.allocator
+)
+
+add_entrypoint_object(
+ calloc
+ SRCS
+ calloc.cpp
+ HDRS
+ ../calloc.h
+ DEPENDS
+ libc.include.stdlib
+ libc.src.__support.GPU.allocator
+)
+
+add_entrypoint_object(
+ aligned_alloc
+ SRCS
+ aligned_alloc.cpp
+ HDRS
+ ../aligned_alloc.h
+ DEPENDS
+ libc.include.stdlib
+ libc.src.__support.GPU.allocator
+)
+
add_entrypoint_object(
abort
SRCS
diff --git a/libc/src/stdlib/gpu/aligned_alloc.cpp b/libc/src/stdlib/gpu/aligned_alloc.cpp
new file mode 100644
index 0000000000000..cd2c7e55128fe
--- /dev/null
+++ b/libc/src/stdlib/gpu/aligned_alloc.cpp
@@ -0,0 +1,29 @@
+//===-- GPU Implementation of aligned_alloc -------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdlib/aligned_alloc.h"
+
+#include "src/__support/GPU/allocator.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(void *, aligned_alloc, (size_t alignment, size_t size)) {
+ if ((alignment & -alignment) != alignment)
+ return nullptr;
+
+ void *ptr = gpu::allocate(size);
+ if ((reinterpret_cast<uintptr_t>(ptr) & (alignment - 1)) != 0) {
+ gpu::deallocate(ptr);
+ return nullptr;
+ }
+ return ptr;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdlib/gpu/calloc.cpp b/libc/src/stdlib/gpu/calloc.cpp
new file mode 100644
index 0000000000000..9150affc7c200
--- /dev/null
+++ b/libc/src/stdlib/gpu/calloc.cpp
@@ -0,0 +1,31 @@
+//===-- GPU Implementation of calloc --------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdlib/calloc.h"
+
+#include "src/__support/GPU/allocator.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/string/memory_utils/inline_memset.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(void *, calloc, (size_t num, size_t size)) {
+ size_t bytes = num * size;
+ if (bytes == 0)
+ return nullptr;
+
+ void *ptr = gpu::allocate(bytes);
+ if (!ptr)
+ return nullptr;
+
+ inline_memset(ptr, 0, bytes);
+ return ptr;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/stdlib/gpu/realloc.cpp b/libc/src/stdlib/gpu/realloc.cpp
new file mode 100644
index 0000000000000..4fd4d6b278179
--- /dev/null
+++ b/libc/src/stdlib/gpu/realloc.cpp
@@ -0,0 +1,32 @@
+//===-- GPU Implementation of realloc -------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/stdlib/realloc.h"
+
+#include "src/__support/GPU/allocator.h"
+#include "src/__support/common.h"
+#include "src/__support/macros/config.h"
+#include "src/string/memory_utils/inline_memcpy.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(void *, realloc, (void *ptr, size_t size)) {
+ if (ptr == nullptr)
+ return gpu::allocate(size);
+
+ void *newmem = gpu::allocate(size);
+ if (newmem == nullptr)
+ return nullptr;
+
+ // This will copy garbage if it goes beyond the old allocation size.
+ inline_memcpy(newmem, ptr, size);
+ gpu::deallocate(ptr);
+ return newmem;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
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