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| author | Quentin Colombet <qcolombet@apple.com> | 2014-03-27 22:27:41 +0000 |
|---|---|---|
| committer | Quentin Colombet <qcolombet@apple.com> | 2014-03-27 22:27:41 +0000 |
| commit | d5f800aab34ae03ecd3b2d4618aa0baba53fe8ab (patch) | |
| tree | 2cc9b455cc51bc3c01d90eca911c51c3f70bb555 /lib | |
| parent | 6bdc4ebedd16bc2102edc4bfbc63c76c7c130ef0 (diff) | |
| download | llvm-d5f800aab34ae03ecd3b2d4618aa0baba53fe8ab.tar.gz llvm-d5f800aab34ae03ecd3b2d4618aa0baba53fe8ab.tar.bz2 llvm-d5f800aab34ae03ecd3b2d4618aa0baba53fe8ab.tar.xz | |
[X86][Vector Cost Model] Add a comment to explain the workaround
in my previous commit (r204884).
<rdar://problem/16381225>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@204972 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Target/X86/X86TargetTransformInfo.cpp | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/lib/Target/X86/X86TargetTransformInfo.cpp b/lib/Target/X86/X86TargetTransformInfo.cpp index 2d44db0acd..f58c94683f 100644 --- a/lib/Target/X86/X86TargetTransformInfo.cpp +++ b/lib/Target/X86/X86TargetTransformInfo.cpp @@ -512,6 +512,11 @@ unsigned X86TTI::getCastInstrCost(unsigned Opcode, Type *Dst, Type *Src) const { { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i8, 2 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i16, 2 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i32, 6 }, + // The generic code to compute the scalar overhead is currently broken. + // Workaround this limitation by estimating the scalarization overhead + // here. We have roughly 10 instructions per scalar element. + // Multiply that by the vector width. + // FIXME: remove that when PR19268 is fixed. { ISD::UINT_TO_FP, MVT::v2f64, MVT::v2i64, 2*10 }, { ISD::UINT_TO_FP, MVT::v4f64, MVT::v4i64, 4*10 }, |