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| author | Chris Lattner <sabre@nondot.org> | 2010-06-26 23:03:20 +0000 |
|---|---|---|
| committer | Chris Lattner <sabre@nondot.org> | 2010-06-26 23:03:20 +0000 |
| commit | 6c5abe88bff9a4cd5abfa8bb793ecfdfc219a06b (patch) | |
| tree | 09b525943d33780f6204975d991fed6834904ae3 /clang/lib/CodeGen/CodeGenFunction.cpp | |
| parent | f00eac5cfff3f3ed6ed99b7f7439664ee2226910 (diff) | |
| download | llvm-6c5abe88bff9a4cd5abfa8bb793ecfdfc219a06b.zip llvm-6c5abe88bff9a4cd5abfa8bb793ecfdfc219a06b.tar.gz llvm-6c5abe88bff9a4cd5abfa8bb793ecfdfc219a06b.tar.bz2 | |
Implement rdar://7530813 - collapse multiple GEP instructions in IRgen
This avoids generating two gep's for common array operations. Before
we would generate something like:
%tmp = load i32* %X.addr ; <i32> [#uses=1]
%arraydecay = getelementptr inbounds [100 x i32]* %A, i32 0, i32 0 ; <i32*> [#uses=1]
%arrayidx = getelementptr inbounds i32* %arraydecay, i32 %tmp ; <i32*> [#uses=1]
%tmp1 = load i32* %arrayidx ; <i32> [#uses=1]
Now we generate:
%tmp = load i32* %X.addr ; <i32> [#uses=1]
%arrayidx = getelementptr inbounds [100 x i32]* %A, i32 0, i32 %tmp ; <i32*> [#uses=1]
%tmp1 = load i32* %arrayidx ; <i32> [#uses=1]
Less IR is better at -O0.
llvm-svn: 106966
Diffstat (limited to 'clang/lib/CodeGen/CodeGenFunction.cpp')
0 files changed, 0 insertions, 0 deletions