1 files changed, 24 insertions, 16 deletions
diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 1f69ffb09c0a..093255e6af2d 100644
--- a/lib/Target/README.txt
+++ b/lib/Target/README.txt
@@ -2,22 +2,6 @@ Target Independent Opportunities:
 
 //===---------------------------------------------------------------------===//
 
-With the recent changes to make the implicit def/use set explicit in
-machineinstrs, we should change the target descriptions for 'call' instructions
-so that the .td files don't list all the call-clobbered registers as implicit
-defs.  Instead, these should be added by the code generator (e.g. on the dag).
-
-This has a number of uses:
-
-1. PPC32/64 and X86 32/64 can avoid having multiple copies of call instructions
-   for their different impdef sets.
-2. Targets with multiple calling convs (e.g. x86) which have different clobber
-   sets don't need copies of call instructions.
-3. 'Interprocedural register allocation' can be done to reduce the clobber sets
-   of calls.
-
-//===---------------------------------------------------------------------===//
-
 We should recognized various "overflow detection" idioms and translate them into
 llvm.uadd.with.overflow and similar intrinsics.  Here is a multiply idiom:
 
@@ -961,6 +945,25 @@ optimized with "clang -emit-llvm-bc | opt -std-compile-opts".
 
 //===---------------------------------------------------------------------===//
 
+int g(int x) { return (x - 10) < 0; }
+Should combine to "x <= 9" (the sub has nsw).  Currently not
+optimized with "clang -emit-llvm-bc | opt -std-compile-opts".
+
+//===---------------------------------------------------------------------===//
+
+int g(int x) { return (x + 10) < 0; }
+Should combine to "x < -10" (the add has nsw).  Currently not
+optimized with "clang -emit-llvm-bc | opt -std-compile-opts".
+
+//===---------------------------------------------------------------------===//
+
+int f(int i, int j) { return i < j + 1; }
+int g(int i, int j) { return j > i - 1; }
+Should combine to "i <= j" (the add/sub has nsw).  Currently not
+optimized with "clang -emit-llvm-bc | opt -std-compile-opts".
+
+//===---------------------------------------------------------------------===//
+
 This was noticed in the entryblock for grokdeclarator in 403.gcc:
 
         %tmp = icmp eq i32 %decl_context, 4          
@@ -2358,3 +2361,8 @@ unsigned foo(unsigned x, unsigned y) { return x > y && x != 0; }
 should fold to x > y.
 
 //===---------------------------------------------------------------------===//
+
+int f(double x) { return __builtin_fabs(x) < 0.0; }
+should fold to false.
+
+//===---------------------------------------------------------------------===//