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| author | Nate Begeman <natebegeman@mac.com> | 2008-02-13 07:06:12 +0000 |
|---|---|---|
| committer | Nate Begeman <natebegeman@mac.com> | 2008-02-13 07:06:12 +0000 |
| commit | d0a08cbba6703803d8b801611a94b7c552eb5817 (patch) | |
| tree | ae404ac41c26af4f30b887b1b3f0c31327913291 /lib/Target/X86/README-SSE.txt | |
| parent | ba7dd484aedc4e186215cbbb1e664f9bb050f27f (diff) | |
| download | external_llvm-d0a08cbba6703803d8b801611a94b7c552eb5817.zip external_llvm-d0a08cbba6703803d8b801611a94b7c552eb5817.tar.gz external_llvm-d0a08cbba6703803d8b801611a94b7c552eb5817.tar.bz2 | |
readme updates
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47051 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/Target/X86/README-SSE.txt')
| -rw-r--r-- | lib/Target/X86/README-SSE.txt | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/lib/Target/X86/README-SSE.txt b/lib/Target/X86/README-SSE.txt index d9a03a3..197dae3 100644 --- a/lib/Target/X86/README-SSE.txt +++ b/lib/Target/X86/README-SSE.txt @@ -781,3 +781,14 @@ any number of 0.0 simultaneously. Currently we only use it for simple insertions. See comments in LowerINSERT_VECTOR_ELT_SSE4. + +//===---------------------------------------------------------------------===// + +On a random note, SSE2 should declare insert/extract of 2 x f64 as legal, not +Custom. All combinations of insert/extract reg-reg, reg-mem, and mem-reg are +legal, it'll just take a few extra patterns written in the .td file. + +Note: this is not a code quality issue; the custom lowered code happens to be +right, but we shouldn't have to custom lower anything. This is probably related +to <2 x i64> ops being so bad. + |