Atomic load/store handling for the passes using memdep (GVN, DSE, memcpyopt).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137888 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 107 insertions, 0 deletions

diff --git a/test/Transforms/DeadStoreElimination/atomic.ll b/test/Transforms/DeadStoreElimination/atomic.ll
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+++ b/test/Transforms/DeadStoreElimination/atomic.ll
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+; RUN: opt -basicaa -dse -S < %s | FileCheck %s
+
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-macosx10.7.0"
+
+; Sanity tests for atomic stores.
+; Note that it turns out essentially every transformation DSE does is legal on
+; atomic ops, just some transformations are not allowed across them. 
+
+@x = common global i32 0, align 4
+@y = common global i32 0, align 4
+
+declare void @randomop(i32*)
+
+; DSE across unordered store (allowed)
+define void @test1()  nounwind uwtable ssp {
+; CHECK: test1
+; CHECK-NOT: store i32 0
+; CHECK: store i32 1
+entry:
+  store i32 0, i32* @x
+  store atomic i32 0, i32* @y unordered, align 4
+  store i32 1, i32* @x
+  ret void
+}
+
+; DSE across seq_cst load (allowed in theory; not implemented ATM)
+define i32 @test2()  nounwind uwtable ssp {
+; CHECK: test2
+; CHECK: store i32 0
+; CHECK: store i32 1
+entry:
+  store i32 0, i32* @x
+  %x = load atomic i32* @y seq_cst, align 4
+  store i32 1, i32* @x
+  ret i32 %x
+}
+
+; DSE across seq_cst store (store before atomic store must not be removed)
+define void @test3()  nounwind uwtable ssp {
+; CHECK: test3
+; CHECK: store i32
+; CHECK: store atomic i32 2
+entry:
+  store i32 0, i32* @x
+  store atomic i32 2, i32* @y seq_cst, align 4
+  store i32 1, i32* @x
+  ret void
+}
+
+; DSE remove unordered store (allowed)
+define void @test4()  nounwind uwtable ssp {
+; CHECK: test4
+; CHECK-NOT: store atomic
+; CHECK: store i32 1
+entry:
+  store atomic i32 0, i32* @x unordered, align 4
+  store i32 1, i32* @x
+  ret void
+}
+
+; DSE unordered store overwriting non-atomic store (allowed)
+define void @test5()  nounwind uwtable ssp {
+; CHECK: test5
+; CHECK: store atomic i32 1
+entry:
+  store i32 0, i32* @x
+  store atomic i32 1, i32* @x unordered, align 4
+  ret void
+}
+
+; DSE no-op unordered atomic store (allowed)
+define void @test6()  nounwind uwtable ssp {
+; CHECK: test6
+; CHECK-NOT: store
+; CHECK: ret void
+entry:
+  %x = load atomic i32* @x unordered, align 4
+  store atomic i32 %x, i32* @x unordered, align 4
+  ret void
+}
+
+; DSE seq_cst store (be conservative; DSE doesn't have infrastructure
+; to reason about atomic operations).
+define void @test7()  nounwind uwtable ssp {
+; CHECK: test7
+; CHECK: store atomic 
+entry:
+  %a = alloca i32
+  store atomic i32 0, i32* %a seq_cst, align 4
+  ret void
+}
+
+; DSE and seq_cst load (be conservative; DSE doesn't have infrastructure
+; to reason about atomic operations).
+define i32 @test8()  nounwind uwtable ssp {
+; CHECK: test8
+; CHECK: store
+; CHECK: load atomic 
+entry:
+  %a = alloca i32
+  call void @randomop(i32* %a)
+  store i32 0, i32* %a, align 4
+  %x = load atomic i32* @x seq_cst, align 4
+  ret i32 %x
+}
+