[InstCombine] Add tests for `icmp eq/ne ({su}div exact X, Y), C`; NFC

[nikic]

LGTM

[goldstein.w.n]

Rebase

llvm/test/Transforms/InstCombine/sdiv-icmp.ll

+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -passes=instcombine -S | FileCheck %s
+
+declare void @use.i8(i8)
+define i1 @sdiv_exact_eq_0(i8 %x, i8 %y) {
+; CHECK-LABEL: @sdiv_exact_eq_0(
+; CHECK-NEXT:    [[D:%.*]] = sdiv exact i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[D]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %d = sdiv exact i8 %x, %y
+  %r = icmp eq i8 %d, 0
+  ret i1 %r
+}
+
+define i1 @udiv_exact_ne_0(i8 %x, i8 %y) {
+; CHECK-LABEL: @udiv_exact_ne_0(
+; CHECK-NEXT:    [[R:%.*]] = icmp ule i8 [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %d = udiv exact i8 %x, %y
+  %r = icmp ne i8 %d, 0
+  ret i1 %r
+}
+
+define i1 @sdiv_exact_ne_1(i8 %x, i8 %y) {
+; CHECK-LABEL: @sdiv_exact_ne_1(
+; CHECK-NEXT:    [[D:%.*]] = sdiv exact i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[D]], 0
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %d = sdiv exact i8 %x, %y
+  %r = icmp eq i8 %d, 0
+  ret i1 %r
+}
+
+define i1 @udiv_exact_eq_1(i8 %x, i8 %y) {
+; CHECK-LABEL: @udiv_exact_eq_1(
+; CHECK-NEXT:    [[D:%.*]] = udiv exact i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[D]], 1
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %d = udiv exact i8 %x, %y
+  %r = icmp ne i8 %d, 1
+  ret i1 %r
+}
+
+define i1 @sdiv_exact_eq_9_no_of(i8 %x, i8 %y) {
+; CHECK-LABEL: @sdiv_exact_eq_9_no_of(
+; CHECK-NEXT:    [[YY:%.*]] = and i8 [[Y:%.*]], 7
+; CHECK-NEXT:    [[D:%.*]] = sdiv exact i8 [[X:%.*]], [[YY]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[D]], 9
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %yy = and i8 %y, 7
+  %d = sdiv exact i8 %x, %yy
+  %r = icmp eq i8 %d, 9
+  ret i1 %r
+}
+
+define i1 @sdiv_exact_eq_9_may_of(i8 %x, i8 %y) {
+; CHECK-LABEL: @sdiv_exact_eq_9_may_of(
+; CHECK-NEXT:    [[D:%.*]] = sdiv exact i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[D]], 9
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %d = sdiv exact i8 %x, %y
+  %r = icmp eq i8 %d, 9
+  ret i1 %r
+}
+
+define i1 @sdiv_exact_eq_9_no_of_fail_multiuse(i8 %x, i8 %y) {
+; CHECK-LABEL: @sdiv_exact_eq_9_no_of_fail_multiuse(
+; CHECK-NEXT:    [[YY:%.*]] = and i8 [[Y:%.*]], 7
+; CHECK-NEXT:    [[D:%.*]] = sdiv exact i8 [[X:%.*]], [[YY]]
+; CHECK-NEXT:    call void @use.i8(i8 [[D]])
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[D]], 9
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %yy = and i8 %y, 7
+  %d = sdiv exact i8 %x, %yy
+  call void @use.i8(i8 %d)
+  %r = icmp eq i8 %d, 9
+  ret i1 %r
+}
+
+define i1 @sdiv_exact_eq_9_must_of_todo_is_false(i8 %x, i8 %y) {
+; CHECK-LABEL: @sdiv_exact_eq_9_must_of_todo_is_false(
+; CHECK-NEXT:    [[YY:%.*]] = or i8 [[Y:%.*]], 55
+; CHECK-NEXT:    [[D:%.*]] = sdiv exact i8 [[X:%.*]], [[YY]]
+; CHECK-NEXT:    [[R:%.*]] = icmp eq i8 [[D]], 9
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %yy = or i8 %y, 55
+  %d = sdiv exact i8 %x, %yy
+  %r = icmp eq i8 %d, 9
+  ret i1 %r
+}
+
+define i1 @udiv_exact_ne_30_no_of(i8 %x, i8 %y) {
+; CHECK-LABEL: @udiv_exact_ne_30_no_of(
+; CHECK-NEXT:    [[YY:%.*]] = and i8 [[Y:%.*]], 7
+; CHECK-NEXT:    [[D:%.*]] = udiv exact i8 [[X:%.*]], [[YY]]
+; CHECK-NEXT:    [[R:%.*]] = icmp ne i8 [[D]], 30
+; CHECK-NEXT:    ret i1 [[R]]
+;
+  %yy = and i8 %y, 7
+  %d = udiv exact i8 %x, %yy
+  %r = icmp ne i8 %d, 30
+  ret i1 %r
+}