Set up MCSchedModel after detecting the CPU type in X86SubTarget.

[oota-llvm.git] / lib / Target / README.txt

diff --git a/lib/Target/README.txt b/lib/Target/README.txt
index 3c21ddae80ca69e94af98cdc88192d3b046b22fe..9c27f27696613fbe69574f384a9752467d6d68eb 100644 (file)
--- 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:
 
@@ -980,6 +964,12 @@ optimized with "clang -emit-llvm-bc | opt -std-compile-opts".
 
 //===---------------------------------------------------------------------===//
 
+unsigned f(unsigned x) { return ((x & 7) + 1) & 15; }
+The & 15 part should be optimized away, it doesn't change the result. 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          
@@ -2377,8 +2367,3 @@ 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.
-
-//===---------------------------------------------------------------------===//