[openmp][nfc] Use builtin align in the devicertl

[JonChesterfield]

Noticed while extracting the smartstack as a test case

[llvmbot]

@llvm/pr-subscribers-offload

Author: Jon Chesterfield (JonChesterfield)

Changes

Noticed while extracting the smartstack as a test case

---

Full diff: https://github.com/llvm/llvm-project/pull/131918.diff

3 Files Affected:

• (modified) offload/DeviceRTL/src/State.cpp (+4-4)
• (modified) offload/include/Shared/Utils.h (+1-10)
• (modified) offload/plugins-nextgen/common/src/PluginInterface.cpp (+1-1)

diff --git a/offload/DeviceRTL/src/State.cpp b/offload/DeviceRTL/src/State.cpp
index cbe9735145340..62b03e7bba720 100644
--- a/offload/DeviceRTL/src/State.cpp
+++ b/offload/DeviceRTL/src/State.cpp
@@ -89,8 +89,8 @@ struct SharedMemorySmartStackTy {
   /// Compute the size of the storage space reserved for a thread.
   uint32_t computeThreadStorageTotal() {
     uint32_t NumLanesInBlock = mapping::getNumberOfThreadsInBlock();
-    return utils::alignDown((state::SharedScratchpadSize / NumLanesInBlock),
-                            allocator::ALIGNMENT);
+    return __builtin_align_down(state::SharedScratchpadSize / NumLanesInBlock,
+                                allocator::ALIGNMENT);
   }
 
   /// Return the top address of the warp data stack, that is the first address
@@ -121,7 +121,7 @@ void *SharedMemorySmartStackTy::push(uint64_t Bytes) {
   // First align the number of requested bytes.
   /// FIXME: The stack shouldn't require worst-case padding. Alignment needs to
   /// be passed in as an argument and the stack rewritten to support it.
-  uint64_t AlignedBytes = utils::alignPtr(Bytes, allocator::ALIGNMENT);
+  uint64_t AlignedBytes = __builtin_align_up(Bytes, allocator::ALIGNMENT);
 
   uint32_t StorageTotal = computeThreadStorageTotal();
 
@@ -149,7 +149,7 @@ void *SharedMemorySmartStackTy::push(uint64_t Bytes) {
 }
 
 void SharedMemorySmartStackTy::pop(void *Ptr, uint64_t Bytes) {
-  uint64_t AlignedBytes = utils::alignPtr(Bytes, allocator::ALIGNMENT);
+  uint64_t AlignedBytes = __builtin_align_up(Bytes, allocator::ALIGNMENT);
   if (utils::isSharedMemPtr(Ptr)) {
     int TId = mapping::getThreadIdInBlock();
     Usage[TId] -= AlignedBytes;
diff --git a/offload/include/Shared/Utils.h b/offload/include/Shared/Utils.h
index 523e6bc505b81..e3d7b002e1b44 100644
--- a/offload/include/Shared/Utils.h
+++ b/offload/include/Shared/Utils.h
@@ -30,18 +30,9 @@ template <typename Ty1, typename Ty2> Ty1 *advancePtr(Ty1 *Ptr, Ty2 Offset) {
   return (Ty1 *)(const_cast<char *>((const char *)(Ptr)) + Offset);
 }
 
-/// Return \p V aligned "upwards" according to \p Align.
-template <typename Ty1, typename Ty2> inline Ty1 alignPtr(Ty1 V, Ty2 Align) {
-  return reinterpret_cast<Ty1>(((uintptr_t(V) + Align - 1) / Align) * Align);
-}
-/// Return \p V aligned "downwards" according to \p Align.
-template <typename Ty1, typename Ty2> inline Ty1 alignDown(Ty1 V, Ty2 Align) {
-  return V - V % Align;
-}
-
 /// Round up \p V to a \p Boundary.
 template <typename Ty> inline Ty roundUp(Ty V, Ty Boundary) {
-  return alignPtr(V, Boundary);
+  return __builtin_align_up(V, Boundary);
 }
 
 /// Return the first bit set in \p V.
diff --git a/offload/plugins-nextgen/common/src/PluginInterface.cpp b/offload/plugins-nextgen/common/src/PluginInterface.cpp
index 4d2ebcbc7be8e..67c8c900ac66f 100644
--- a/offload/plugins-nextgen/common/src/PluginInterface.cpp
+++ b/offload/plugins-nextgen/common/src/PluginInterface.cpp
@@ -78,7 +78,7 @@ struct RecordReplayTy {
         Device->allocate(1024, /*HstPtr=*/nullptr, TARGET_ALLOC_DEFAULT);
     Device->free(Addr);
     // Align Address to MaxMemoryAllocation
-    Addr = (void *)utils::alignPtr((Addr), MaxMemoryAllocation);
+    Addr = __builtin_align_up(Addr, MaxMemoryAllocation);
     return Addr;
   }
 

[jhuber6]

This is compiled with as low as GCC 7.3 I believe, though we are floating around making the projects build deprecated. Does GCC support this?

[shiltian]

Google says it is 10. Too high.

[JonChesterfield]

Well that's sad. Oh well, can still drop the utils from State.cpp. Reduced the scope of the patch accordingly.

[jhuber6]

We can revisit once we make the projects build illegal.