[ValueTracking] Add tests for non-constant idx in computeKnownBits of insertelement; NFC

Author: goldsteinn

llvm/test/Transforms/InstCombine/insertelement.ll

@@ -25,3 +25,53 @@ define <4 x i32> @insert_unknown_idx(<4 x i32> %x, i32 %idx) {
   %v3 = and <4 x i32> %v2, <i32 7, i32 7, i32 7, i32 7>
   ret <4 x i32> %v3
 }
+
+define <2 x i8> @insert_known_any_idx(<2 x i8> %xx, i8 %yy, i32 %idx) {
+; CHECK-LABEL: @insert_known_any_idx(
+; CHECK-NEXT:    [[X:%.*]] = or <2 x i8> [[XX:%.*]], <i8 16, i8 16>
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[YY:%.*]], 16
+; CHECK-NEXT:    [[INS:%.*]] = insertelement <2 x i8> [[X]], i8 [[Y]], i32 [[IDX:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = and <2 x i8> [[INS]], <i8 16, i8 16>
+; CHECK-NEXT:    ret <2 x i8> [[R]]
+;
+  %x = or <2 x i8> %xx, <i8 16, i8 16>
+  %y = or i8 %yy, 16
+
+  %ins = insertelement <2 x i8> %x, i8 %y, i32 %idx
+  %r = and <2 x i8> %ins, <i8 16, i8 16>
+  ret <2 x i8> %r
+}
+
+define <2 x i8> @insert_known_any_idx_fail1(<2 x i8> %xx, i8 %yy, i32 %idx) {
+; CHECK-LABEL: @insert_known_any_idx_fail1(
+; CHECK-NEXT:    [[X:%.*]] = or <2 x i8> [[XX:%.*]], <i8 17, i8 33>
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[YY:%.*]], 16
+; CHECK-NEXT:    [[INS:%.*]] = insertelement <2 x i8> [[X]], i8 [[Y]], i32 [[IDX:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = and <2 x i8> [[INS]], <i8 16, i8 16>
+; CHECK-NEXT:    ret <2 x i8> [[R]]
+;
+  %x = or <2 x i8> %xx, <i8 17, i8 33>
+  %y = or i8 %yy, 16
+
+  %ins = insertelement <2 x i8> %x, i8 %y, i32 %idx
+  %r = and <2 x i8> %ins, <i8 16, i8 16>
+  ret <2 x i8> %r
+}
+
+
+define <2 x i8> @insert_known_any_idx_fail2(<2 x i8> %xx, i8 %yy, i32 %idx) {
+; CHECK-LABEL: @insert_known_any_idx_fail2(
+; CHECK-NEXT:    [[X:%.*]] = or <2 x i8> [[XX:%.*]], <i8 17, i8 31>
+; CHECK-NEXT:    [[Y:%.*]] = or i8 [[YY:%.*]], 15
+; CHECK-NEXT:    [[INS:%.*]] = insertelement <2 x i8> [[X]], i8 [[Y]], i32 [[IDX:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = and <2 x i8> [[INS]], <i8 16, i8 16>
+; CHECK-NEXT:    ret <2 x i8> [[R]]
+;
+  %x = or <2 x i8> %xx, <i8 17, i8 31>
+  %y = or i8 %yy, 15
+
+  %ins = insertelement <2 x i8> %x, i8 %y, i32 %idx
+  %r = and <2 x i8> %ins, <i8 16, i8 16>
+  ret <2 x i8> %r
+}
+