two simple testcases loopreduce should handle but does not yet currently

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@22682 91177308-0d34-0410-b5e6-96231b3b80d8

test/Transforms/LoopStrengthReduce/exit_compare_live_range.ll

@@ -0,0 +1,21 @@
+; Make sure that the compare instruction occurs after the increment to avoid
+; having overlapping live ranges that result in copies.  We want the setcc instruction
+; immediately before the conditional branch.
+;
+; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis | %prcontext 'br bool' 1 | grep set
+; XFAIL: *
+
+void %foo(float* %D, uint %E) {
+entry:
+	br label %no_exit
+
+no_exit:
+	%indvar = phi uint [ 0, %entry ], [ %indvar.next, %no_exit ]
+	volatile store float 0.0, float* %D
+	%indvar.next = add uint %indvar, 1		; <uint> [#uses=2]
+	%exitcond = seteq uint %indvar.next, %E		; <bool> [#uses=1]
+	br bool %exitcond, label %loopexit, label %no_exit
+
+loopexit:
+	ret void
+}

test/Transforms/LoopStrengthReduce/related_indvars.ll

@@ -0,0 +1,29 @@
+; RUN: llvm-as < %s | opt -loop-reduce | llvm-dis | grep phi | wc -l | grep 1
+
+; This should only result in one PHI node!
+; XFAIL: *
+
+; void foo(double *D, double *E, double F) {
+;   while (D != E)
+;     *D++ = F;
+; }
+
+void %foo(double* %D, double* %E, double %F) {
+entry:
+	%tmp.24 = seteq double* %D, %E		; <bool> [#uses=1]
+	br bool %tmp.24, label %return, label %no_exit
+
+no_exit:		; preds = %no_exit, %entry
+	%indvar = phi uint [ 0, %entry ], [ %indvar.next, %no_exit ]		; <uint> [#uses=3]
+	%D_addr.0.0.rec = cast uint %indvar to int		; <int> [#uses=1]
+	%D_addr.0.0 = getelementptr double* %D, uint %indvar		; <double*> [#uses=1]
+	%inc.rec = add int %D_addr.0.0.rec, 1		; <int> [#uses=1]
+	%inc = getelementptr double* %D, int %inc.rec		; <double*> [#uses=1]
+	store double %F, double* %D_addr.0.0
+	%tmp.2 = seteq double* %inc, %E		; <bool> [#uses=1]
+	%indvar.next = add uint %indvar, 1		; <uint> [#uses=1]
+	br bool %tmp.2, label %return, label %no_exit
+
+return:		; preds = %no_exit, %entry
+	ret void
+}