Temporarily revert r58979 and related patch. It's causing a failure in X86 bootstrap:

Comparing stages 2 and 3
warning: ./cc1-checksum.o differs
warning: ./cc1obj-checksum.o differs
warning: ./cc1objplus-checksum.o differs
warning: ./cc1plus-checksum.o differs
Bootstrap comparison failure!
./alias.o differs
./alloc-pool.o differs
./attribs.o differs
./bb-reorder.o differs
./bitmap.o differs
./build/errors.o differs
./build/genattrtab.o differs
./build/genautomata.o differs
./build/genemit.o differs
./build/genextract.o differs
...

-bw


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@59003 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/SelectionDAG/TargetLowering.cpp

@@ -1353,6 +1353,7 @@ TargetLowering::SimplifySetCC(MVT VT, SDValue N0, SDValue N1,
         }
       }
 
+#if 0
       // If the LHS is '(and load, const)', the RHS is 0,
       // the test is for equality or unsigned, and all 1 bits of the const are
       // in the same partial word, see if we can shorten the load.
@@ -1406,7 +1407,8 @@ TargetLowering::SimplifySetCC(MVT VT, SDValue N0, SDValue N1,
           }
         }
       }
-     
+#endif
+
       // If the LHS is a ZERO_EXTEND, perform the comparison on the input.
       if (N0.getOpcode() == ISD::ZERO_EXTEND) {
         unsigned InSize = N0.getOperand(0).getValueType().getSizeInBits();

test/CodeGen/X86/2008-11-06-testb.ll

@@ -1,4 +1,6 @@
 ; RUN: llvm-as < %s | llc -mtriple=i386-apple-darwin | grep testb
+; XFAIL: *
+
 ; ModuleID = '<stdin>'
 target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
 target triple = "i386-apple-darwin9.5"