ret <2 x i1> %D
}
-define i1 @test19(i32 %A) {
-; CHECK-LABEL: @test19(
-; CHECK-NEXT: [[TMP1:%.*]] = or i32 %A, 1
+; if LHSC and RHSC differ only by one bit:
+; (A == C1 || A == C2) -> (A | (C1 ^ C2)) == C2
+; PR14708: https://bugs.llvm.org/show_bug.cgi?id=14708
+
+define i1 @cmp_eq_with_one_bit_diff_constants1(i32 %x) {
+; CHECK-LABEL: @cmp_eq_with_one_bit_diff_constants1(
+; CHECK-NEXT: [[TMP1:%.*]] = or i32 %x, 1
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 51
; CHECK-NEXT: ret i1 [[TMP2]]
;
- %B = icmp eq i32 %A, 50
- %C = icmp eq i32 %A, 51
- %D = or i1 %B, %C
- ret i1 %D
+ %cmp1 = icmp eq i32 %x, 50
+ %cmp2 = icmp eq i32 %x, 51
+ %or = or i1 %cmp1, %cmp2
+ ret i1 %or
+}
+
+; The constants are not necessarily off-by-one, just off-by-one-bit.
+
+define i1 @cmp_eq_with_one_bit_diff_constants2(i32 %x) {
+; CHECK-LABEL: @cmp_eq_with_one_bit_diff_constants2(
+; CHECK-NEXT: [[TMP1:%.*]] = or i32 %x, 32
+; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i32 [[TMP1]], 97
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %cmp1 = icmp eq i32 %x, 97
+ %cmp2 = icmp eq i32 %x, 65
+ %or = or i1 %cmp1, %cmp2
+ ret i1 %or
+}
+
+; Make sure the constants are treated as unsigned when comparing them.
+
+define i1 @cmp_eq_with_one_bit_diff_constants3(i8 %x) {
+; CHECK-LABEL: @cmp_eq_with_one_bit_diff_constants3(
+; CHECK-NEXT: [[TMP1:%.*]] = or i8 %x, -128
+; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i8 [[TMP1]], -2
+; CHECK-NEXT: ret i1 [[TMP2]]
+;
+ %cmp1 = icmp eq i8 %x, 254
+ %cmp2 = icmp eq i8 %x, 126
+ %or = or i1 %cmp1, %cmp2
+ ret i1 %or
+}
+
+; Use an 'add' to eliminate an icmp if the constants are off-by-one (not off-by-one-bit).
+; (X == 13 | X == 14) -> X-13 <u 2
+
+define i1 @cmp_eq_with_diff_one(i8 %x) {
+; CHECK-LABEL: @cmp_eq_with_diff_one(
+; CHECK-NEXT: [[X_OFF:%.*]] = add i8 %x, -13
+; CHECK-NEXT: [[TMP1:%.*]] = icmp ult i8 [[X_OFF]], 2
+; CHECK-NEXT: ret i1 [[TMP1]]
+;
+ %cmp1 = icmp eq i8 %x, 13
+ %cmp2 = icmp eq i8 %x, 14
+ %or = or i1 %cmp1, %cmp2
+ ret i1 %or
}
+; Make sure the constants are treated as signed when comparing them.
; PR32524: https://bugs.llvm.org/show_bug.cgi?id=32524
-define i1 @or_icmps_eq_diff1(i32 %x) {
-; CHECK-LABEL: @or_icmps_eq_diff1(
+define i1 @cmp_eq_with_diff_one_signed(i32 %x) {
+; CHECK-LABEL: @cmp_eq_with_diff_one_signed(
; CHECK-NEXT: [[CMP1:%.*]] = icmp eq i32 %x, -1
; CHECK-NEXT: [[CMP2:%.*]] = icmp eq i32 %x, 0
-; CHECK-NEXT: [[LOGIC:%.*]] = or i1 [[CMP1]], [[CMP2]]
-; CHECK-NEXT: ret i1 [[LOGIC]]
+; CHECK-NEXT: [[OR:%.*]] = or i1 [[CMP1]], [[CMP2]]
+; CHECK-NEXT: ret i1 [[OR]]
;
%cmp1 = icmp eq i32 %x, -1
%cmp2 = icmp eq i32 %x, 0
- %logic = or i1 %cmp1, %cmp2
- ret i1 %logic
+ %or = or i1 %cmp1, %cmp2
+ ret i1 %or
}
define i32 @test20(i32 %x) {