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| author | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2013-12-27 20:20:28 +0000 |
|---|---|---|
| committer | Andrea Di Biagio <Andrea_DiBiagio@sn.scee.net> | 2013-12-27 20:20:28 +0000 |
| commit | b2f47c6a3455a9d265e21c8ab1ca81657ff577a0 (patch) | |
| tree | cfaadbd40840df2293deec78b068ce832fafb91f /include | |
| parent | bd75475bfcbf81c0f6e3a67511c16704c7da8b7a (diff) | |
| download | llvm-b2f47c6a3455a9d265e21c8ab1ca81657ff577a0.tar.gz llvm-b2f47c6a3455a9d265e21c8ab1ca81657ff577a0.tar.bz2 llvm-b2f47c6a3455a9d265e21c8ab1ca81657ff577a0.tar.xz | |
Teach DAGCombiner how to fold a SIGN_EXTEND_INREG of a BUILD_VECTOR of
ConstantSDNodes (or UNDEFs) into a simple BUILD_VECTOR.
For example, given the following sequence of dag nodes:
i32 C = Constant<1>
v4i32 V = BUILD_VECTOR C, C, C, C
v4i32 Result = SIGN_EXTEND_INREG V, ValueType:v4i1
The SIGN_EXTEND_INREG node can be folded into a build_vector since
the vector in input is a BUILD_VECTOR of constants.
The optimized sequence is:
i32 C = Constant<-1>
v4i32 Result = BUILD_VECTOR C, C, C, C
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198084 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'include')
| -rw-r--r-- | include/llvm/CodeGen/SelectionDAGNodes.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/llvm/CodeGen/SelectionDAGNodes.h b/include/llvm/CodeGen/SelectionDAGNodes.h index 70c15e6c6e..08eda723c6 100644 --- a/include/llvm/CodeGen/SelectionDAGNodes.h +++ b/include/llvm/CodeGen/SelectionDAGNodes.h @@ -70,6 +70,10 @@ namespace ISD { /// BUILD_VECTOR where all of the elements are 0 or undef. bool isBuildVectorAllZeros(const SDNode *N); + /// \brief Return true if the specified node is a BUILD_VECTOR node of + /// all ConstantSDNode or undef. + bool isBuildVectorOfConstantSDNodes(const SDNode *N); + /// isScalarToVector - Return true if the specified node is a /// ISD::SCALAR_TO_VECTOR node or a BUILD_VECTOR node where only the low /// element is not an undef. |