diff options
| -rw-r--r-- | lib/Target/X86/README.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt index b8ec59ae36..af520afe1d 100644 --- a/lib/Target/X86/README.txt +++ b/lib/Target/X86/README.txt @@ -1166,4 +1166,13 @@ pressure. The scheduling issue is more pronounced without -static. The 2) marked instructions are the lowered form of the 1,undef,3,4 shufflevector. It seems that there should be a better way to do it :) +//===---------------------------------------------------------------------===// + +If shorter, we should use things like: +movzwl %ax, %eax +instead of: +andl $65535, %EAX + +The former can also be used when the two-addressy nature of the 'and' would +require a copy to be inserted (in X86InstrInfo::convertToThreeAddress). |