[llvm-commits] CVS: llvm/lib/Target/X86/README.txt

[Chris Lattner]

Changes in directory llvm/lib/Target/X86:

README.txt updated: 1.26 -> 1.27
---
Log message:

add a missed optimization


---
Diffs of the changes:  (+10 -0)

 README.txt |   10 ++++++++++
 1 files changed, 10 insertions(+)


Index: llvm/lib/Target/X86/README.txt
diff -u llvm/lib/Target/X86/README.txt:1.26 llvm/lib/Target/X86/README.txt:1.27
--- llvm/lib/Target/X86/README.txt:1.26	Sun Jan 29 00:48:25 2006
+++ llvm/lib/Target/X86/README.txt	Sun Jan 29 03:08:15 2006
@@ -204,3 +204,13 @@
    disambiguate the pointers.
 
 Number 1 is the preferred solution.
+
+//===---------------------------------------------------------------------===//
+
+The instruction selector sometimes misses folding a load into a compare.  The
+pattern is written as (cmp reg, (load p)).  Because the compare isn't 
+commutative, it is not matched with the load on both sides.  The dag combiner
+should be made smart enough to cannonicalize the load into the RHS of a compare
+when it can invert the result of the compare for free.
+
+