https://github.com/Pierre-vh created
https://github.com/llvm/llvm-project/pull/148630
Directly plug it into the MMO instead, which is much cleaner.
>From d8aad39519972bf64d868e9f54ac45862b92686a Mon Sep 17 00:00:00 2001
From: pvanhout <pierre.vanhoutr...@amd.com>
Date: Mon, 14 Jul 2025 15:02:31 +0200
Subject: [PATCH] [NFC][AMDGPU] Refactor handling of `amdgpu-synchronize-as` MD
on fences
Directly plug it into the MMO instead, which is much cleaner.
---
llvm/lib/Target/AMDGPU/SIMemoryLegalizer.cpp | 32 ++++++++++++--------
1 file changed, 19 insertions(+), 13 deletions(-)
diff --git a/llvm/lib/Target/AMDGPU/SIMemoryLegalizer.cpp
b/llvm/lib/Target/AMDGPU/SIMemoryLegalizer.cpp
index 123fbfe0b2a48..0e8a420fbb70a 100644
--- a/llvm/lib/Target/AMDGPU/SIMemoryLegalizer.cpp
+++ b/llvm/lib/Target/AMDGPU/SIMemoryLegalizer.cpp
@@ -705,15 +705,15 @@ void diagnoseUnknownMMRAASName(const MachineInstr &MI,
StringRef AS) {
}
/// Reads \p MI's MMRAs to parse the "amdgpu-synchronize-as" MMRA.
-/// If this tag isn't present, or if it has no meaningful values, returns \p
-/// Default. Otherwise returns all the address spaces concerned by the MMRA.
-static SIAtomicAddrSpace getFenceAddrSpaceMMRA(const MachineInstr &MI,
- SIAtomicAddrSpace Default) {
+/// If this tag isn't present, or if it has no meaningful values, returns
+/// \p none, otherwise returns the address spaces specified by the MD.
+static std::optional<SIAtomicAddrSpace>
+getSynchronizeAddrSpaceMD(const MachineInstr &MI) {
static constexpr StringLiteral FenceASPrefix = "amdgpu-synchronize-as";
auto MMRA = MMRAMetadata(MI.getMMRAMetadata());
if (!MMRA)
- return Default;
+ return std::nullopt;
SIAtomicAddrSpace Result = SIAtomicAddrSpace::NONE;
for (const auto &[Prefix, Suffix] : MMRA) {
@@ -726,7 +726,10 @@ static SIAtomicAddrSpace getFenceAddrSpaceMMRA(const
MachineInstr &MI,
diagnoseUnknownMMRAASName(MI, Suffix);
}
- return (Result != SIAtomicAddrSpace::NONE) ? Result : Default;
+ if (Result == SIAtomicAddrSpace::NONE)
+ return std::nullopt;
+
+ return Result;
}
} // end anonymous namespace
@@ -903,12 +906,19 @@ SIMemOpAccess::getAtomicFenceInfo(const
MachineBasicBlock::iterator &MI) const {
std::tie(Scope, OrderingAddrSpace, IsCrossAddressSpaceOrdering) =
*ScopeOrNone;
- if ((OrderingAddrSpace == SIAtomicAddrSpace::NONE) ||
- ((OrderingAddrSpace & SIAtomicAddrSpace::ATOMIC) != OrderingAddrSpace)) {
+ if (OrderingAddrSpace != SIAtomicAddrSpace::ATOMIC) {
+ // We currently expect refineOrderingAS to be the only place that
+ // can refine the AS ordered by the fence.
+ // If that changes, we need to review the semantics of that function
+ // in case it needs to preserve certain address spaces.
reportUnsupported(MI, "Unsupported atomic address space");
return std::nullopt;
}
+ auto SynchronizeAS = getSynchronizeAddrSpaceMD(*MI);
+ if (SynchronizeAS)
+ OrderingAddrSpace = *SynchronizeAS;
+
return SIMemOpInfo(Ordering, Scope, OrderingAddrSpace,
SIAtomicAddrSpace::ATOMIC,
IsCrossAddressSpaceOrdering, AtomicOrdering::NotAtomic);
}
@@ -2687,11 +2697,7 @@ bool SIMemoryLegalizer::expandAtomicFence(const
SIMemOpInfo &MOI,
AtomicPseudoMIs.push_back(MI);
bool Changed = false;
- // Refine fenced address space based on MMRAs.
- //
- // TODO: Should we support this MMRA on other atomic operations?
- auto OrderingAddrSpace =
- getFenceAddrSpaceMMRA(*MI, MOI.getOrderingAddrSpace());
+ const SIAtomicAddrSpace OrderingAddrSpace = MOI.getOrderingAddrSpace();
if (MOI.isAtomic()) {
const AtomicOrdering Order = MOI.getOrdering();
_______________________________________________
llvm-branch-commits mailing list
llvm-branch-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
