A few new entries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28683 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/X86/README.txt b/lib/Target/X86/README.txt
index 590a6dbebacba4463e7fa558cebb39c19b6f8767..3e40027e9b6e2c9f72849ad836dc00abba647996 100644 (file)
--- a/lib/Target/X86/README.txt
+++ b/lib/Target/X86/README.txt
@@ -538,6 +538,9 @@ _foo:
        sarl $24, %eax
        ret
 
+SIGN_EXTEND_INREG can be implemented as (sext (trunc)) to take advantage of 
+sub-registers.
+
 //===---------------------------------------------------------------------===//
 
 Consider this:
@@ -649,3 +652,19 @@ estimate to determine whether the match is profitable.
 
 However, if we care more about code size, then imull is better. It's two bytes
 shorter than movl + leal.
+
+//===---------------------------------------------------------------------===//
+
+Implement CTTZ, CTLZ with bsf and bsr.
+
+//===---------------------------------------------------------------------===//
+
+It appears gcc place string data with linkonce linkage in
+.section __TEXT,__const_coal,coalesced instead of
+.section __DATA,__const_coal,coalesced.
+Take a look at darwin.h, there are other Darwin assembler directives that we
+do not make use of.
+
+//===---------------------------------------------------------------------===//
+
+We should handle __attribute__ ((__visibility__ ("hidden"))).