Avoid splitting an interval multiple times; avoid splitting re-materializable val# (for now).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58068 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/X86/pre-split1.ll b/test/CodeGen/X86/pre-split1.ll
new file mode 100644
index 0000000..f99ac89
--- /dev/null
+++ b/test/CodeGen/X86/pre-split1.ll
@@ -0,0 +1,23 @@
+; RUN: llvm-as < %s | llc -march=x86 -mattr=+sse2 -pre-alloc-split -stats |& \
+; RUN:   grep {pre-alloc-split} | grep {Number of intervals split} | grep 1
+
+define void @test(double* %P, i32 %cond) nounwind {
+entry:
+	%0 = load double* %P, align 8		; <double> [#uses=1]
+	%1 = add double %0, 4.000000e+00		; <double> [#uses=2]
+	%2 = icmp eq i32 %cond, 0		; <i1> [#uses=1]
+	br i1 %2, label %bb1, label %bb
+
+bb:		; preds = %entry
+	%3 = add double %1, 4.000000e+00		; <double> [#uses=1]
+	br label %bb1
+
+bb1:		; preds = %bb, %entry
+	%A.0 = phi double [ %3, %bb ], [ %1, %entry ]		; <double> [#uses=1]
+	%4 = mul double %A.0, 4.000000e+00		; <double> [#uses=1]
+	%5 = tail call i32 (...)* @bar() nounwind		; <i32> [#uses=0]
+	store double %4, double* %P, align 8
+	ret void
+}
+
+declare i32 @bar(...)