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| author | Chris Lattner <sabre@nondot.org> | 2010-11-30 07:23:21 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-11-30 07:23:21 +0000 |
| commit | cf82dc376a11acb1b5d46d56c032bb0b9326c682 (patch) | |
| tree | 5465dd3586d482a9c497d0d4a84f94b3d44581b0 /test/Transforms/DeadStoreElimination | |
| parent | c413330c99a573ef3ffe80a46400b1d3eca2398d (diff) | |
| download | llvm-cf82dc376a11acb1b5d46d56c032bb0b9326c682.tar.gz llvm-cf82dc376a11acb1b5d46d56c032bb0b9326c682.tar.bz2 llvm-cf82dc376a11acb1b5d46d56c032bb0b9326c682.tar.xz | |
Rewrite the main DSE loop to be written in terms of reasoning
about pairs of AA::Location's instead of looking for MemDep's
"Def" predicate. This is more powerful and general, handling
memset/memcpy/store all uniformly, and implementing PR8701 and
probably obsoleting parts of memcpyoptimizer.
This also fixes an obscure bug with init.trampoline and i8
stores, but I'm not surprised it hasn't been hit yet. Enhancing
init.trampoline to carry the size that it stores would allow
DSE to be much more aggressive about optimizing them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120406 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/DeadStoreElimination')
| -rw-r--r-- | test/Transforms/DeadStoreElimination/simple.ll | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/test/Transforms/DeadStoreElimination/simple.ll b/test/Transforms/DeadStoreElimination/simple.ll index 1aa62bb6e0..0c05b15357 100644 --- a/test/Transforms/DeadStoreElimination/simple.ll +++ b/test/Transforms/DeadStoreElimination/simple.ll @@ -177,3 +177,36 @@ define void @test14(i32* %Q) { ; CHECK-NEXT: ret void } + +; PR8701 + +;; Fully dead overwrite of memcpy. +define void @test15(i8* %P, i8* %Q) nounwind ssp { + tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1) + tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1) + ret void +; CHECK: @test15 +; CHECK-NEXT: call void @llvm.memcpy +; CHECK-NEXT: ret +} + +;; Full overwrite of smaller memcpy. +define void @test16(i8* %P, i8* %Q) nounwind ssp { + tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 8, i32 1) + tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1) + ret void +; CHECK: @test16 +; CHECK-NEXT: call void @llvm.memcpy +; CHECK-NEXT: ret +} + +;; Overwrite of memset by memcpy. +define void @test17(i8* %P, i8* %Q) nounwind ssp { + tail call void @llvm.memset.i64(i8* %P, i8 42, i64 8, i32 1) + tail call void @llvm.memcpy.i64(i8* %P, i8* %Q, i64 12, i32 1) + ret void +; CHECK: @test17 +; CHECK-NEXT: call void @llvm.memcpy +; CHECK-NEXT: ret +} + |