--- /dev/null
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -aggressive-instcombine -S | FileCheck %s
+
+define i16 @trunc_shl(i16 %x, i16 %y) {
+; CHECK-LABEL: @trunc_shl(
+; CHECK-NEXT: [[CMP0:%.*]] = icmp ult i16 [[Y:%.*]], 16
+; CHECK-NEXT: call void @llvm.assume(i1 [[CMP0]])
+; CHECK-NEXT: [[ZEXTX:%.*]] = zext i16 [[X:%.*]] to i32
+; CHECK-NEXT: [[ZEXTY:%.*]] = zext i16 [[Y]] to i32
+; CHECK-NEXT: [[I0:%.*]] = shl i32 [[ZEXTX]], [[ZEXTY]]
+; CHECK-NEXT: [[R:%.*]] = trunc i32 [[I0]] to i16
+; CHECK-NEXT: ret i16 [[R]]
+;
+ %cmp0 = icmp ult i16 %y, 16
+ call void @llvm.assume(i1 %cmp0)
+
+ %zextx = zext i16 %x to i32
+ %zexty = zext i16 %y to i32
+
+ %i0 = shl i32 %zextx, %zexty
+ %r = trunc i32 %i0 to i16
+ ret i16 %r
+}
+
+define i16 @trunc_lshr(i16 %x, i16 %y) {
+; CHECK-LABEL: @trunc_lshr(
+; CHECK-NEXT: [[CMP0:%.*]] = icmp ult i16 [[X:%.*]], 0
+; CHECK-NEXT: [[CMP1:%.*]] = icmp ult i16 [[Y:%.*]], 16
+; CHECK-NEXT: call void @llvm.assume(i1 [[CMP0]])
+; CHECK-NEXT: call void @llvm.assume(i1 [[CMP1]])
+; CHECK-NEXT: [[ZEXTX:%.*]] = zext i16 [[X]] to i32
+; CHECK-NEXT: [[ZEXTY:%.*]] = zext i16 [[Y]] to i32
+; CHECK-NEXT: [[I0:%.*]] = lshr i32 [[ZEXTX]], [[ZEXTY]]
+; CHECK-NEXT: [[R:%.*]] = trunc i32 [[I0]] to i16
+; CHECK-NEXT: ret i16 [[R]]
+;
+ %cmp0 = icmp ult i16 %x, 65536
+ %cmp1 = icmp ult i16 %y, 16
+ call void @llvm.assume(i1 %cmp0)
+ call void @llvm.assume(i1 %cmp1)
+
+ %zextx = zext i16 %x to i32
+ %zexty = zext i16 %y to i32
+
+ %i0 = lshr i32 %zextx, %zexty
+ %r = trunc i32 %i0 to i16
+ ret i16 %r
+}
+
+define i16 @trunc_ashr(i16 %x, i16 %y) {
+; CHECK-LABEL: @trunc_ashr(
+; CHECK-NEXT: [[CMP0:%.*]] = icmp slt i16 [[X:%.*]], 32767
+; CHECK-NEXT: [[CMP1:%.*]] = icmp sge i16 [[X]], -32768
+; CHECK-NEXT: [[CMP2:%.*]] = icmp ult i16 [[Y:%.*]], 16
+; CHECK-NEXT: call void @llvm.assume(i1 [[CMP0]])
+; CHECK-NEXT: call void @llvm.assume(i1 [[CMP1]])
+; CHECK-NEXT: call void @llvm.assume(i1 [[CMP2]])
+; CHECK-NEXT: [[ZEXTX:%.*]] = sext i16 [[X]] to i32
+; CHECK-NEXT: [[ZEXTY:%.*]] = sext i16 [[Y]] to i32
+; CHECK-NEXT: [[I0:%.*]] = ashr i32 [[ZEXTX]], [[ZEXTY]]
+; CHECK-NEXT: [[R:%.*]] = trunc i32 [[I0]] to i16
+; CHECK-NEXT: ret i16 [[R]]
+;
+ %cmp0 = icmp slt i16 %x, 32767
+ %cmp1 = icmp sge i16 %x, -32768
+ %cmp2 = icmp ult i16 %y, 16
+ call void @llvm.assume(i1 %cmp0)
+ call void @llvm.assume(i1 %cmp1)
+ call void @llvm.assume(i1 %cmp2)
+
+ %zextx = sext i16 %x to i32
+ %zexty = sext i16 %y to i32
+
+ %i0 = ashr i32 %zextx, %zexty
+ %r = trunc i32 %i0 to i16
+ ret i16 %r
+}
+
+declare void @llvm.assume(i1)