fix a bug I introduced with my 'instcombine builder' refactoring

changes: SimplifyDemandedBits can't use the builder yet because it
has the wrong insertion point.  This fixes a crash building
MultiSource/Benchmarks/PAQ8p

llvm-svn: 80537

llvm/lib/Transforms/Scalar/InstructionCombining.cpp

@@ -1010,8 +1010,12 @@ Value *InstCombiner::SimplifyDemandedUseBits(Value *V, APInt DemandedMask,
     // If all of the demanded bits are known to be zero on one side or the
     // other, turn this into an *inclusive* or.
     //    e.g. (A & C1)^(B & C2) -> (A & C1)|(B & C2) iff C1&C2 == 0
-    if ((DemandedMask & ~RHSKnownZero & ~LHSKnownZero) == 0)
-      return Builder->CreateOr(I->getOperand(0), I->getOperand(1),I->getName());
+    if ((DemandedMask & ~RHSKnownZero & ~LHSKnownZero) == 0) {
+      Instruction *Or = 
+        BinaryOperator::CreateOr(I->getOperand(0), I->getOperand(1),
+                                 I->getName());
+      return InsertNewInstBefore(Or, *I);
+    }
     
     // If all of the demanded bits on one side are known, and all of the set
     // bits on that side are also known to be set on the other side, turn this

llvm/test/Transforms/InstCombine/crash.ll

@@ -0,0 +1,14 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis
+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-darwin10.0"
+
+define i32 @_Z9model8bitR5Mixeri(i8 %tmp2) ssp {
+entry:
+  %tmp3 = zext i8 %tmp2 to i32
+  %tmp8 = lshr i32 %tmp3, 6 
+  %tmp9 = lshr i32 %tmp3, 7 
+  %tmp10 = xor i32 %tmp9, 67108858
+  %tmp11 = xor i32 %tmp10, %tmp8 
+  %tmp12 = xor i32 %tmp11, 0     
+  ret i32 %tmp12
+}