xref: /llvm-project/llvm/test/Transforms/InstCombine/pr75129.ll (revision 7be5dabbc26a5e42dab82e6502c5d9a38e0e3b72)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=instcombine -S | FileCheck %s
3
4; Pattern:
5;   (or (and (add x, half_c1), c3), (and x, c2))
6; IFF:
7;   c1, c2, c3 is constant
8;   c1 is pow2
9;   c2 < c1
10;   c3 == (c1 - 1) ^ c2
11;   half_c1 == (lshr c1, 1)
12;   (c1 >> 1) & c3 == (c1 >> 1)
13;   x is known to be less than c1
14; Could be transformed into:
15;   (xor x, half_c1)
16; The reason above transformation could be done is becase
17; in (and (add x, half_c1), c3), half_c1 equals the top bit
18; of the demanded mask indicated by (and ..., c3)
19
20define i16 @or_and_add_and() {
21; CHECK-LABEL: @or_and_add_and(
22; CHECK-NEXT:  entry:
23; CHECK-NEXT:    [[X:%.*]] = call i16 @dummy(), !range [[RNG0:![0-9]+]]
24; CHECK-NEXT:    [[OR:%.*]] = xor i16 [[X]], 32
25; CHECK-NEXT:    ret i16 [[OR]]
26;
27entry:
28  %x = call i16 @dummy(), !range !0
29  %add = add i16 32, %x
30  %and1 = and i16 %add, 48
31  %and2 = and i16 %x, 15
32  %or = or i16 %and1, %and2
33  ret i16 %or
34}
35
36declare i16 @dummy()
37
38!0 = !{i16 0, i16 64}
39