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| author | Benjamin Kramer <benny.kra@googlemail.com> | 2011-02-12 17:58:16 +0000 |
|---|---|---|
| committer | Benjamin Kramer <benny.kra@googlemail.com> | 2011-02-12 17:58:16 +0000 |
| commit | d800cf0a509b79ba80b6f4d9b170ccd83661560e (patch) | |
| tree | 1faa032fbbaba361afc034dae53baed2098531d6 | |
| parent | 609d54ee1e715af57e499c2cd10ff5a9ba89b9f2 (diff) | |
Add a note about SSE4.1 roundss/roundsd.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125438 91177308-0d34-0410-b5e6-96231b3b80d8
| -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 b2116e03b14..f16ec029e96 100644 --- a/lib/Target/X86/README-SSE.txt +++ b/lib/Target/X86/README-SSE.txt @@ -923,4 +923,15 @@ The insertps's of $0 are pointless complex copies. //===---------------------------------------------------------------------===// +If SSE4.1 is available we should inline rounding functions instead of emitting +a libcall. +floor: roundsd $0x01, %xmm, %xmm +ceil: roundsd $0x02, %xmm, %xmm + +and likewise for the single precision versions. + +Currently, SelectionDAGBuilder doesn't turn calls to these functions into the +corresponding nodes and some targets (including X86) aren't ready for them. + +//===---------------------------------------------------------------------===// |