From: Evan Cheng Date: Wed, 29 Mar 2006 03:03:46 +0000 (+0000) Subject: Another entry about shuffles. X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=c999c745c0e94b15c14e5dca44d23c572b89f9ef;p=oota-llvm.git Another entry about shuffles. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@27245 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index 09d9bb6ef86..060552b93de 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -667,3 +667,9 @@ directly %esp[0] if there are no other uses. Use movhps to update upper 64-bits of a v4sf value. Also movlps on lower half of a v4sf value. + +//===---------------------------------------------------------------------===// + +Better codegen for vector_shuffles like this { x, 0, 0, 0 } or { x, 0, x, 0}. +Perhaps use pxor / xorp* to clear a XMM register first? +