Add support for folding binary operators with vector zero operands.

llvm-svn: 43510
diff --git a/llvm/test/Transforms/InstCombine/fold-vector-zero.ll b/llvm/test/Transforms/InstCombine/fold-vector-zero.ll
new file mode 100644
index 0000000..0b5b30a
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/fold-vector-zero.ll
@@ -0,0 +1,35 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep zeroinitializer
+
+define void @foo(i64 %A, i64 %B) {
+bb8:
+	br label %bb30
+
+bb30:
+	%s0 = phi i64 [ 0, %bb8 ], [ %r21, %bb30 ]
+	%l0 = phi i64 [ -2222, %bb8 ], [ %r23, %bb30 ]
+	%r2 = add i64 %s0, %B
+	%r3 = inttoptr i64 %r2 to <2 x double>*
+	%r4 = load <2 x double>* %r3, align 8
+	%r6 = bitcast <2 x double> %r4 to <2 x i64>
+	%r7 = bitcast <2 x double> zeroinitializer to <2 x i64>
+	%r8 = insertelement <2 x i64> undef, i64 9223372036854775807, i32 0
+	%r9 = insertelement <2 x i64> undef, i64 -9223372036854775808, i32 0
+	%r10 = insertelement <2 x i64> %r8, i64 9223372036854775807, i32 1
+	%r11 = insertelement <2 x i64> %r9, i64 -9223372036854775808, i32 1
+	%r12 = and <2 x i64> %r6, %r10
+	%r13 = and <2 x i64> %r7, %r11
+	%r14 = or <2 x i64> %r12, %r13
+	%r15 = bitcast <2 x i64> %r14 to <2 x double>
+	%r18 = add i64 %s0, %A
+	%r19 = inttoptr i64 %r18 to <2 x double>*
+	store <2 x double> %r15, <2 x double>* %r19, align 8
+	%r21 = add i64 16, %s0
+	%r23 = add i64 1, %l0
+	%r25 = icmp slt i64 %r23, 0
+	%r26 = zext i1 %r25 to i64
+	%r27 = icmp ne i64 %r26, 0
+	br i1 %r27, label %bb30, label %bb5
+
+bb5:
+	ret void
+}