xref: /llvm-project/llvm/test/Transforms/InstCombine/pr75129.ll (revision 7be5dabbc26a5e42dab82e6502c5d9a38e0e3b72)
1*7be5dabbSFujun Han; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2*7be5dabbSFujun Han; RUN: opt < %s -passes=instcombine -S | FileCheck %s
3*7be5dabbSFujun Han
4*7be5dabbSFujun Han; Pattern:
5*7be5dabbSFujun Han;   (or (and (add x, half_c1), c3), (and x, c2))
6*7be5dabbSFujun Han; IFF:
7*7be5dabbSFujun Han;   c1, c2, c3 is constant
8*7be5dabbSFujun Han;   c1 is pow2
9*7be5dabbSFujun Han;   c2 < c1
10*7be5dabbSFujun Han;   c3 == (c1 - 1) ^ c2
11*7be5dabbSFujun Han;   half_c1 == (lshr c1, 1)
12*7be5dabbSFujun Han;   (c1 >> 1) & c3 == (c1 >> 1)
13*7be5dabbSFujun Han;   x is known to be less than c1
14*7be5dabbSFujun Han; Could be transformed into:
15*7be5dabbSFujun Han;   (xor x, half_c1)
16*7be5dabbSFujun Han; The reason above transformation could be done is becase
17*7be5dabbSFujun Han; in (and (add x, half_c1), c3), half_c1 equals the top bit
18*7be5dabbSFujun Han; of the demanded mask indicated by (and ..., c3)
19*7be5dabbSFujun Han
20*7be5dabbSFujun Handefine i16 @or_and_add_and() {
21*7be5dabbSFujun Han; CHECK-LABEL: @or_and_add_and(
22*7be5dabbSFujun Han; CHECK-NEXT:  entry:
23*7be5dabbSFujun Han; CHECK-NEXT:    [[X:%.*]] = call i16 @dummy(), !range [[RNG0:![0-9]+]]
24*7be5dabbSFujun Han; CHECK-NEXT:    [[OR:%.*]] = xor i16 [[X]], 32
25*7be5dabbSFujun Han; CHECK-NEXT:    ret i16 [[OR]]
26*7be5dabbSFujun Han;
27*7be5dabbSFujun Hanentry:
28*7be5dabbSFujun Han  %x = call i16 @dummy(), !range !0
29*7be5dabbSFujun Han  %add = add i16 32, %x
30*7be5dabbSFujun Han  %and1 = and i16 %add, 48
31*7be5dabbSFujun Han  %and2 = and i16 %x, 15
32*7be5dabbSFujun Han  %or = or i16 %and1, %and2
33*7be5dabbSFujun Han  ret i16 %or
34*7be5dabbSFujun Han}
35*7be5dabbSFujun Han
36*7be5dabbSFujun Handeclare i16 @dummy()
37*7be5dabbSFujun Han
38*7be5dabbSFujun Han!0 = !{i16 0, i16 64}
39