[test] precommit some tests for D143883 NFC

[nikic]

LGTM

llvm/test/Transforms/InstCombine/urem-via-cmp-select.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+; TODO: https://alive2.llvm.org/ce/z/5eCiWi
+define i8 @urem_assume(i8 %x, i8 %n) {
+; CHECK-LABEL: @urem_assume(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[X:%.*]], [[N:%.*]]
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[ADD:%.*]] = add nuw i8 [[X]], 1
+; CHECK-NEXT:    [[OUT:%.*]] = urem i8 [[ADD]], [[N]]
+; CHECK-NEXT:    ret i8 [[OUT]]
+;
+  %cmp = icmp ult i8 %x, %n
+  tail call void @llvm.assume(i1 %cmp)
+  %add = add nuw i8 %x, 1
+  %out = urem i8 %add, %n
+  ret i8 %out
+}
+
+; TODO: https://alive2.llvm.org/ce/z/MGgtYN
+define i8 @urem_assume_without_nuw(i8 %x, i8 %n) {
+; CHECK-LABEL: @urem_assume_without_nuw(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[X:%.*]], [[N:%.*]]
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[X]], 1
+; CHECK-NEXT:    [[OUT:%.*]] = urem i8 [[ADD]], [[N]]
+; CHECK-NEXT:    ret i8 [[OUT]]
+;
+  %cmp = icmp ult i8 %x, %n
+  tail call void @llvm.assume(i1 %cmp)
+  %add = add i8 %x, 1
+  %out = urem i8 %add, %n
+  ret i8 %out
+}
+
+; Negative test: The assume is false
+define i8 @urem_assume_eq(i8 %x, i8 %n) {
+; CHECK-LABEL: @urem_assume_eq(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[X:%.*]], [[N:%.*]]
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[X]], 1
+; CHECK-NEXT:    [[OUT:%.*]] = urem i8 [[ADD]], [[N]]
+; CHECK-NEXT:    ret i8 [[OUT]]
+;
+  %cmp = icmp eq i8 %x, %n
+  tail call void @llvm.assume(i1 %cmp)
+  %add = add i8 %x, 1
+  %out = urem i8 %add, %n
+  ret i8 %out
+}
+
+; Negative test: The assume is false
+define i8 @urem_assume_ne(i8 %x, i8 %n) {
+; CHECK-LABEL: @urem_assume_ne(
+; CHECK-NEXT:  start:
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ne i8 [[X:%.*]], [[N:%.*]]
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[X]], 1
+; CHECK-NEXT:    [[OUT:%.*]] = urem i8 [[ADD]], [[N]]
+; CHECK-NEXT:    ret i8 [[OUT]]
+;
+start:
+  %cmp = icmp ne i8 %x, %n
+  tail call void @llvm.assume(i1 %cmp)
+  %add = add i8 %x, 1
+  %out = urem i8 %add, %n
+  ret i8 %out
+}
+
+; Negative test: The add constant is not 1
+define i8 @urem_assume_with_unexpected_const(i8 %x, i8 %n) {
+; CHECK-LABEL: @urem_assume_with_unexpected_const(
+; CHECK-NEXT:    [[CMP:%.*]] = icmp ult i8 [[X:%.*]], [[N:%.*]]
+; CHECK-NEXT:    tail call void @llvm.assume(i1 [[CMP]])
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[X]], 2
+; CHECK-NEXT:    [[OUT:%.*]] = urem i8 [[ADD]], [[N]]
+; CHECK-NEXT:    ret i8 [[OUT]]
+;
+  %cmp = icmp ult i8 %x, %n
+  tail call void @llvm.assume(i1 %cmp)
+  %add = add i8 %x, 2            ; Transform only when the constant is 1
+  %out = urem i8 %add, %n
+  ret i8 %out
+}
+
+; TODO: https://alive2.llvm.org/ce/z/gNhZ2x
+define i8 @urem_without_assume(i8 %arg, i8 %arg2) {
+; CHECK-LABEL: @urem_without_assume(
+; CHECK-NEXT:    [[X:%.*]] = urem i8 [[ARG:%.*]], [[ARG2:%.*]]
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[X]], 1
+; CHECK-NEXT:    [[OUT:%.*]] = urem i8 [[ADD]], [[ARG2]]
+; CHECK-NEXT:    ret i8 [[OUT]]
+;
+  %x = urem i8 %arg, %arg2
+  %add = add i8 %x, 1
+  %out = urem i8 %add, %arg2
+  ret i8 %out
+}
+
+; TODO: https://alive2.llvm.org/ce/z/eHkgRa
+define i8 @urem_with_dominating_condition(i8 %x, i8 %n) {
+; CHECK-LABEL: @urem_with_dominating_condition(
+; CHECK-NEXT:    [[COND:%.*]] = icmp ult i8 [[X:%.*]], [[N:%.*]]
+; CHECK-NEXT:    br i1 [[COND]], label [[DOTBB0:%.*]], label [[DOTBB1:%.*]]
+; CHECK:       .bb0:
+; CHECK-NEXT:    [[ADD:%.*]] = add i8 [[X]], 1
+; CHECK-NEXT:    [[OUT:%.*]] = urem i8 [[ADD]], [[N]]
+; CHECK-NEXT:    ret i8 [[OUT]]
+; CHECK:       .bb1:
+; CHECK-NEXT:    ret i8 0
+;
+  %cond = icmp ult i8 %x, %n
+  br i1 %cond, label %.bb0, label %.bb1 ; Should also works for a dominating condition
+.bb0:
+  %add = add i8 %x, 1
+  %out = urem i8 %add, %n
+  ret i8 %out
+.bb1:
+  ret i8 0
+}
+
+declare void @llvm.assume(i1 noundef)