TRUNCATE constant folding - minor fix for rL233224
Fix for test case found by James Molloy - TRUNCATE of constant build vectors can be more simply achieved by simply replacing with a new build vector node with the truncated value type - no need to touch the scalar operands at all.
llvm-svn: 235079
diff --git a/llvm/test/CodeGen/AArch64/fold-constants.ll b/llvm/test/CodeGen/AArch64/fold-constants.ll
new file mode 100644
index 0000000..2dd0d12
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/fold-constants.ll
@@ -0,0 +1,21 @@
+; RUN: llc -mtriple=aarch64-linux-gnu -o - %s | FileCheck %s
+
+define i64 @dotests_616() {
+; CHECK-LABEL: dotests_616
+; CHECK: movi d0, #0000000000000000
+; CHECK-NEXT: umov w8, v0.b[2]
+; CHECK-NEXT: sbfx w8, w8, #0, #1
+; CHECK-NEXT: fmov s0, w8
+; CHECK-NEXT: fmov x0, d0
+; CHECK-NEXT: ret
+entry:
+ %0 = bitcast <2 x i64> zeroinitializer to <8 x i16>
+ %1 = and <8 x i16> zeroinitializer, %0
+ %2 = icmp ne <8 x i16> %1, zeroinitializer
+ %3 = extractelement <8 x i1> %2, i32 2
+ %vgetq_lane285 = sext i1 %3 to i16
+ %vset_lane = insertelement <4 x i16> undef, i16 %vgetq_lane285, i32 0
+ %4 = bitcast <4 x i16> %vset_lane to <1 x i64>
+ %vget_lane = extractelement <1 x i64> %4, i32 0
+ ret i64 %vget_lane
+}