Author: Hans Wennborg Date: 2020-02-28T11:27:33+01:00 New Revision: 7cb6829291280a2adcc260346a7a56b8bddd43db
URL: https://github.com/llvm/llvm-project/commit/7cb6829291280a2adcc260346a7a56b8bddd43db DIFF: https://github.com/llvm/llvm-project/commit/7cb6829291280a2adcc260346a7a56b8bddd43db.diff LOG: SROA: Don't drop atomic load/store alignments (PR45010) SROA will drop the explicit alignment on allocas when the ABI guarantees enough alignment. Because the alignment on new load/store instructions are set based on the alloca's alignment, that means SROA would end up dropping the alignment from atomic loads and stores, which is not allowed (see bug). For those, make sure to always carry over the alignment from the previous instruction. Differential revision: https://reviews.llvm.org/D75266 (cherry picked from commit d48c981697a49653efff9dd14fa692d99e6fa868) Added: Modified: llvm/lib/Transforms/Scalar/SROA.cpp llvm/test/Transforms/SROA/alignment.ll Removed: ################################################################################ diff --git a/llvm/lib/Transforms/Scalar/SROA.cpp b/llvm/lib/Transforms/Scalar/SROA.cpp index 89916e43fce2..1bdd806f15ac 100644 --- a/llvm/lib/Transforms/Scalar/SROA.cpp +++ b/llvm/lib/Transforms/Scalar/SROA.cpp @@ -2519,6 +2519,8 @@ class llvm::sroa::AllocaSliceRewriter NewLI->setAAMetadata(AATags); if (LI.isVolatile()) NewLI->setAtomic(LI.getOrdering(), LI.getSyncScopeID()); + if (NewLI->isAtomic()) + NewLI->setAlignment(LI.getAlign()); // Any !nonnull metadata or !range metadata on the old load is also valid // on the new load. This is even true in some cases even when the loads @@ -2709,6 +2711,8 @@ class llvm::sroa::AllocaSliceRewriter NewSI->setAAMetadata(AATags); if (SI.isVolatile()) NewSI->setAtomic(SI.getOrdering(), SI.getSyncScopeID()); + if (NewSI->isAtomic()) + NewSI->setAlignment(SI.getAlign()); Pass.DeadInsts.insert(&SI); deleteIfTriviallyDead(OldOp); diff --git a/llvm/test/Transforms/SROA/alignment.ll b/llvm/test/Transforms/SROA/alignment.ll index 81f8f2a00ba8..674f45fb1665 100644 --- a/llvm/test/Transforms/SROA/alignment.ll +++ b/llvm/test/Transforms/SROA/alignment.ll @@ -228,4 +228,19 @@ define void @test10() { ret void } +%struct = type { i32, i32 } +define dso_local i32 @pr45010(%struct* %A) { +; CHECK-LABEL: @pr45010 +; CHECK: load atomic volatile i32, {{.*}}, align 4 + + %B = alloca %struct, align 4 + %A.i = getelementptr inbounds %struct, %struct* %A, i32 0, i32 0 + %B.i = getelementptr inbounds %struct, %struct* %B, i32 0, i32 0 + %1 = load i32, i32* %A.i, align 4 + store atomic volatile i32 %1, i32* %B.i release, align 4 + %2 = bitcast %struct* %B to i32* + %x = load atomic volatile i32, i32* %2 acquire, align 4 + ret i32 %x +} + declare void @populate(i8*) _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
