New entry.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41810 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index 1f53227136246c76b4b4c9696cec4684e98ec9ae..40cbd864354db07a62cf3f0da4ef33a1a69b463b 100644 (file)
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -1205,3 +1205,6 @@ __Z11no_overflowjj:
 
 
 //===---------------------------------------------------------------------===//
+
+Re-materialize MOV32r0 etc. with xor instead of changing them to moves if the
+condition register is dead. xor reg reg is shorter than mov reg, #0.