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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2010-12-24 21:17:12 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2010-12-24 21:17:12 +0000 |
| commit | a112087e4298ca8ec1bc8aef8a2b272e49faa7ac (patch) | |
| tree | a73adc09f5bde9f7041ab07031e39ed7806415f8 /test/Transforms/MemCpyOpt/memcpy-to-memset.ll | |
| parent | 4010dd72b81b760daaa0361084de6dca8ed86fa1 (diff) | |
| download | llvm-a112087e4298ca8ec1bc8aef8a2b272e49faa7ac.tar.gz llvm-a112087e4298ca8ec1bc8aef8a2b272e49faa7ac.tar.bz2 llvm-a112087e4298ca8ec1bc8aef8a2b272e49faa7ac.tar.xz | |
MemCpyOpt: Turn memcpys from a constant into a memset if possible.
This allows us to compile "int cst[] = {-1, -1, -1};" into
movl $-1, 16(%rsp)
movq $-1, 8(%rsp)
instead of
movl _cst+8(%rip), %eax
movl %eax, 16(%rsp)
movq _cst(%rip), %rax
movq %rax, 8(%rsp)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@122548 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'test/Transforms/MemCpyOpt/memcpy-to-memset.ll')
| -rw-r--r-- | test/Transforms/MemCpyOpt/memcpy-to-memset.ll | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/test/Transforms/MemCpyOpt/memcpy-to-memset.ll b/test/Transforms/MemCpyOpt/memcpy-to-memset.ll new file mode 100644 index 0000000000..b18d176f00 --- /dev/null +++ b/test/Transforms/MemCpyOpt/memcpy-to-memset.ll @@ -0,0 +1,19 @@ +; RUN: opt -memcpyopt -S < %s | FileCheck %s + +@cst = internal constant [3 x i32] [i32 -1, i32 -1, i32 -1], align 4 + +declare void @llvm.memcpy.p0i8.p0i8.i64(i8* nocapture, i8* nocapture, i64, i32, i1) nounwind +declare void @foo(i32*) nounwind + +define void @test1() nounwind { + %arr = alloca [3 x i32], align 4 + %arr_i8 = bitcast [3 x i32]* %arr to i8* + call void @llvm.memcpy.p0i8.p0i8.i64(i8* %arr_i8, i8* bitcast ([3 x i32]* @cst to i8*), i64 12, i32 4, i1 false) + %arraydecay = getelementptr inbounds [3 x i32]* %arr, i64 0, i64 0 + call void @foo(i32* %arraydecay) nounwind + ret void +; CHECK: @test1 +; CHECK: call void @llvm.memset +; CHECK-NOT: call void @llvm.memcpy +; CHECK: ret void +} |