From: Benjamin Kramer Date: Sat, 12 Feb 2011 17:58:16 +0000 (+0000) Subject: Add a note about SSE4.1 roundss/roundsd. X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=d800cf0a509b79ba80b6f4d9b170ccd83661560e;p=oota-llvm.git 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 --- 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. + +//===---------------------------------------------------------------------===//