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| author | Igor Laevsky <igmyrj@gmail.com> | 2015-07-11 10:30:36 +0000 |
|---|---|---|
| committer | Igor Laevsky <igmyrj@gmail.com> | 2015-07-11 10:30:36 +0000 |
| commit | 39d662f7ba0aa80799a2c6ea2ca84b0c0727db66 (patch) | |
| tree | 1486500f54fd10e5c5b7b147dffcaf5a7c6b9bac /llvm/test/Analysis/BasicAA/modref.ll | |
| parent | 15f5d9731123d31af0baf935fbcc07a001d11ebd (diff) | |
| download | bcm5719-llvm-39d662f7ba0aa80799a2c6ea2ca84b0c0727db66.tar.gz bcm5719-llvm-39d662f7ba0aa80799a2c6ea2ca84b0c0727db66.zip | |
Add argmemonly attribute.
This change adds new attribute called "argmemonly". Function marked with this attribute can only access memory through it's argument pointers. This attribute directly corresponds to the "OnlyAccessesArgumentPointees" ModRef behaviour in alias analysis.
Differential Revision: http://reviews.llvm.org/D10398
llvm-svn: 241979
Diffstat (limited to 'llvm/test/Analysis/BasicAA/modref.ll')
| -rw-r--r-- | llvm/test/Analysis/BasicAA/modref.ll | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/llvm/test/Analysis/BasicAA/modref.ll b/llvm/test/Analysis/BasicAA/modref.ll index e124d6cbe20..3084f809c37 100644 --- a/llvm/test/Analysis/BasicAA/modref.ll +++ b/llvm/test/Analysis/BasicAA/modref.ll @@ -145,6 +145,51 @@ entry: ; CHECK: load i32, i32* } +;; Check that aa correctly handles functions marked with argmemonly +;; attribute. +declare i32 @func_argmemonly(i32 * %P) argmemonly + +;; Can not remove redundant load, function may write to it. +; CHECK-LABEL: @test8( +define i32 @test8(i32 *%P) { + %V1 = load i32, i32* %P + call i32 @func_argmemonly(i32* %P) + %V2 = load i32, i32* %P + %Diff = sub i32 %V1, %V2 + ret i32 %Diff + ; CHECK: load + ; CHECK: load + ; CHECK: sub + ; CHECK: ret i32 %Diff +} + +;; In this case load can be removed, function clobbers only %P2. +; CHECK-LABEL: @test9( +define i32 @test9(i32* %P, i32* noalias %P2) { + %V1 = load i32, i32* %P + call i32 @func_argmemonly(i32* %P2) + %V2 = load i32, i32* %P + %Diff = sub i32 %V1, %V2 + ret i32 %Diff + ; CHECK-NOT: load + ; CHECK: ret i32 0 +} + +;; In this case load can *not* be removed. Function clobers only %P2 but it may +;; alias with %P. +; CHECK-LABEL: @test10( +define i32 @test10(i32* %P, i32* %P2) { + %V1 = load i32, i32* %P + call i32 @func_argmemonly(i32* %P2) + %V2 = load i32, i32* %P + %Diff = sub i32 %V1, %V2 + ret i32 %Diff + ; CHECK: load + ; CHECK: load + ; CHECK: sub + ; CHECK: ret i32 %Diff +} + declare void @llvm.memset.p0i8.i32(i8* nocapture, i8, i32, i32, i1) nounwind declare void @llvm.memset.p0i8.i8(i8* nocapture, i8, i8, i32, i1) nounwind declare void @llvm.memcpy.p0i8.p0i8.i8(i8* nocapture, i8* nocapture, i8, i32, i1) nounwind |
