[InstCombine] add tests for icmp-of-and-of-select-of-constants; NFC

This overlaps with the tests proposed in D134064
and providing coverage for D133919, but it is
both limited in scope and more comprehensive
because there are many potential ways to transform
these kinds of patterns.

Author: rotateright

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

@@ -192,8 +192,8 @@ define i1 @icmp_select_implied_cond_ne(i8 %x, i8 %y) {
 define i1 @icmp_select_implied_cond_swapped_select(i8 %x, i8 %y) {
 ; CHECK-LABEL: @icmp_select_implied_cond_swapped_select(
 ; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[X:%.*]], 0
-; CHECK-NEXT:    [[CMP21:%.*]] = icmp eq i8 [[Y:%.*]], 0
-; CHECK-NEXT:    [[CMP2:%.*]] = select i1 [[CMP1]], i1 [[CMP21]], i1 false
+; CHECK-NEXT:    [[TMP1:%.*]] = icmp eq i8 [[Y:%.*]], 0
+; CHECK-NEXT:    [[CMP2:%.*]] = select i1 [[CMP1]], i1 [[TMP1]], i1 false
 ; CHECK-NEXT:    ret i1 [[CMP2]]
 ;
   %cmp1 = icmp eq i8 %x, 0
@@ -259,3 +259,150 @@ define i1 @umin_seq_comparison(i8 %x, i8 %y) {
   %cmp2 = icmp eq i8 %sel, %x
   ret i1 %cmp2
 }
+
+define i1 @select_constants_and_icmp_eq0(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0(
+; CHECK-NEXT:    [[S1:%.*]] = select i1 [[X:%.*]], i8 2, i8 1
+; CHECK-NEXT:    [[S2:%.*]] = select i1 [[Y:%.*]], i8 2, i8 1
+; CHECK-NEXT:    [[AND:%.*]] = and i8 [[S1]], [[S2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[AND]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %s1 = select i1 %x, i8 2, i8 1
+  %s2 = select i1 %y, i8 2, i8 1
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 0
+  ret i1 %cmp
+}
+
+define i1 @select_constants_and_icmp_eq0_uses(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0_uses(
+; CHECK-NEXT:    [[S1:%.*]] = select i1 [[X:%.*]], i8 2, i8 1
+; CHECK-NEXT:    call void @use(i8 [[S1]])
+; CHECK-NEXT:    [[S2:%.*]] = select i1 [[Y:%.*]], i8 2, i8 1
+; CHECK-NEXT:    call void @use(i8 [[S2]])
+; CHECK-NEXT:    [[AND:%.*]] = and i8 [[S1]], [[S2]]
+; CHECK-NEXT:    call void @use(i8 [[AND]])
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[AND]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %s1 = select i1 %x, i8 2, i8 1
+  call void @use(i8 %s1)
+  %s2 = select i1 %y, i8 2, i8 1
+  call void @use(i8 %s2)
+  %and = and i8 %s1, %s2
+  call void @use(i8 %and)
+  %cmp = icmp eq i8 %and, 0
+  ret i1 %cmp
+}
+
+define <2 x i1> @select_constants_and_icmp_eq0_vec_splat(<2 x i1> %x, <2 x i1> %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0_vec_splat(
+; CHECK-NEXT:    [[S1:%.*]] = select <2 x i1> [[X:%.*]], <2 x i9> <i9 3, i9 3>, <2 x i9> <i9 48, i9 48>
+; CHECK-NEXT:    [[S2:%.*]] = select <2 x i1> [[Y:%.*]], <2 x i9> <i9 3, i9 3>, <2 x i9> <i9 48, i9 48>
+; CHECK-NEXT:    [[AND:%.*]] = and <2 x i9> [[S1]], [[S2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq <2 x i9> [[AND]], zeroinitializer
+; CHECK-NEXT:    ret <2 x i1> [[CMP]]
+;
+  %s1 = select <2 x i1> %x, <2 x i9> <i9 3, i9 3>, <2 x i9> <i9 48, i9 48>
+  %s2 = select <2 x i1> %y, <2 x i9> <i9 3, i9 3>, <2 x i9> <i9 48, i9 48>
+  %and = and <2 x i9> %s1, %s2
+  %cmp = icmp eq <2 x i9> %and, zeroinitializer
+  ret <2 x i1> %cmp
+}
+
+define i1 @select_constants_and_icmp_eq0_common_bit(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0_common_bit(
+; CHECK-NEXT:    ret i1 false
+;
+  %s1 = select i1 %x, i8 2, i8 3
+  %s2 = select i1 %y, i8 2, i8 3
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 0
+  ret i1 %cmp
+}
+
+define i1 @select_constants_and_icmp_eq0_no_common_op1(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0_no_common_op1(
+; CHECK-NEXT:    [[S1:%.*]] = select i1 [[X:%.*]], i8 16, i8 3
+; CHECK-NEXT:    [[S2:%.*]] = select i1 [[Y:%.*]], i8 24, i8 3
+; CHECK-NEXT:    [[AND:%.*]] = and i8 [[S1]], [[S2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[AND]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %s1 = select i1 %x, i8 16, i8 3
+  %s2 = select i1 %y, i8 24, i8 3
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 0
+  ret i1 %cmp
+}
+
+define i1 @select_constants_and_icmp_eq0_no_common_op2(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0_no_common_op2(
+; CHECK-NEXT:    [[S1:%.*]] = select i1 [[X:%.*]], i8 16, i8 3
+; CHECK-NEXT:    [[S2:%.*]] = select i1 [[Y:%.*]], i8 16, i8 7
+; CHECK-NEXT:    [[AND:%.*]] = and i8 [[S1]], [[S2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[AND]], 0
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %s1 = select i1 %x, i8 16, i8 3
+  %s2 = select i1 %y, i8 16, i8 7
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 0
+  ret i1 %cmp
+}
+
+define i1 @select_constants_and_icmp_eq0_zero_tval(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0_zero_tval(
+; CHECK-NEXT:    [[TMP1:%.*]] = select i1 [[X:%.*]], i1 true, i1 [[Y:%.*]]
+; CHECK-NEXT:    ret i1 [[TMP1]]
+;
+  %s1 = select i1 %x, i8 0, i8 12
+  %s2 = select i1 %y, i8 0, i8 12
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 0
+  ret i1 %cmp
+}
+
+define i1 @select_constants_and_icmp_eq0_zero_fval(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq0_zero_fval(
+; CHECK-NEXT:    [[TMP1:%.*]] = select i1 [[X:%.*]], i1 [[Y:%.*]], i1 false
+; CHECK-NEXT:    [[NOT_:%.*]] = xor i1 [[TMP1]], true
+; CHECK-NEXT:    ret i1 [[NOT_]]
+;
+  %s1 = select i1 %x, i8 12, i8 0
+  %s2 = select i1 %y, i8 12, i8 0
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 0
+  ret i1 %cmp
+}
+
+define i1 @select_constants_and_icmp_eq_tval(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq_tval(
+; CHECK-NEXT:    [[S1:%.*]] = select i1 [[X:%.*]], i8 6, i8 1
+; CHECK-NEXT:    [[S2:%.*]] = select i1 [[Y:%.*]], i8 6, i8 1
+; CHECK-NEXT:    [[AND:%.*]] = and i8 [[S1]], [[S2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[AND]], 6
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %s1 = select i1 %x, i8 6, i8 1
+  %s2 = select i1 %y, i8 6, i8 1
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 6
+  ret i1 %cmp
+}
+
+define i1 @select_constants_and_icmp_eq_fval(i1 %x, i1 %y) {
+; CHECK-LABEL: @select_constants_and_icmp_eq_fval(
+; CHECK-NEXT:    [[S1:%.*]] = select i1 [[X:%.*]], i8 12, i8 3
+; CHECK-NEXT:    [[S2:%.*]] = select i1 [[Y:%.*]], i8 12, i8 3
+; CHECK-NEXT:    [[AND:%.*]] = and i8 [[S1]], [[S2]]
+; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i8 [[AND]], 3
+; CHECK-NEXT:    ret i1 [[CMP]]
+;
+  %s1 = select i1 %x, i8 12, i8 3
+  %s2 = select i1 %y, i8 12, i8 3
+  %and = and i8 %s1, %s2
+  %cmp = icmp eq i8 %and, 3
+  ret i1 %cmp
+}