From 69affe6a944d6d703dbdca530471a0b2480c1385 Mon Sep 17 00:00:00 2001 From: Benjamin Kramer Date: Sat, 12 Feb 2011 17:58:16 +0000 Subject: Add a note about SSE4.1 roundss/roundsd. llvm-svn: 125438 --- llvm/lib/Target/X86/README-SSE.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'llvm/lib') diff --git a/llvm/lib/Target/X86/README-SSE.txt b/llvm/lib/Target/X86/README-SSE.txt index b2116e03b14..f16ec029e96 100644 --- a/llvm/lib/Target/X86/README-SSE.txt +++ b/llvm/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. + +//===---------------------------------------------------------------------===// -- cgit v1.2.3