9dc7da3f9c
This is a long standing problem that resurfaces once in a while [0].
There might actually be two problems because I'm not 100% sure if the
issue underlying https://reviews.llvm.org/D115302 would be solved by
this or not. Anyway.
In 2008 we thought intrinsics do not read/write globals passed to them:
d4133ac315
This is not correct given that intrinsics can synchronize threads and
cause effects to effectively become visible.
NOTE: I did not yet modify any tests but only tried out the reproducer
of https://github.com/llvm/llvm-project/issues/54851.
Fixes: https://github.com/llvm/llvm-project/issues/54851
[0] https://discourse.llvm.org/t/bug-gvn-memdep-bug-in-the-presence-of-intrinsics/59402
Differential Revision: https://reviews.llvm.org/D123531
39 lines
1.3 KiB
LLVM
39 lines
1.3 KiB
LLVM
; RUN: opt -globals-aa -gvn -S < %s | FileCheck %s
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; RUN: opt -aa-pipeline=basic-aa,globals-aa -passes='require<globals-aa>,gvn' -S < %s | FileCheck %s
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;
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; Functions w/o `nosync` attribute may communicate via memory and must be
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; treated conservatively. Taken from https://reviews.llvm.org/D115302.
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target datalayout = "e-i64:64-i128:128-v16:16-v32:32-n16:32:64"
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target triple = "nvptx64-nvidia-cuda"
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@s = internal local_unnamed_addr addrspace(3) global i32 undef, align 4
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; CHECK-LABEL: @bar_sync
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; CHECK: store
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; CHECK: tail call void @llvm.nvvm.bar.sync(i32 0)
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; CHECK: load
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define dso_local i32 @bar_sync(i32 %0) local_unnamed_addr {
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store i32 %0, i32* addrspacecast (i32 addrspace(3)* @s to i32*), align 4
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tail call void @llvm.nvvm.bar.sync(i32 0)
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%2 = load i32, i32* addrspacecast (i32 addrspace(3)* @s to i32*), align 4
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ret i32 %2
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}
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declare void @llvm.nvvm.bar.sync(i32) #0
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; CHECK-LABEL: @barrier0
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; CHECK: store
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; CHECK: tail call void @llvm.nvvm.barrier0()
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; CHECK: load
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define dso_local i32 @barrier0(i32 %0) local_unnamed_addr {
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store i32 %0, i32* addrspacecast (i32 addrspace(3)* @s to i32*), align 4
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tail call void @llvm.nvvm.barrier0()
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%2 = load i32, i32* addrspacecast (i32 addrspace(3)* @s to i32*), align 4
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ret i32 %2
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}
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declare void @llvm.nvvm.barrier0() #0
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attributes #0 = { convergent nounwind }
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