reference, declarationdefinition
definition → references, declarations, derived classes, virtual overrides
reference to multiple definitions → definitions
unreferenced
    1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103
  104
  105
  106
  107
  108
  109
  110
  111
  112
  113
  114
  115
  116
  117
  118
  119
  120
  121
  122
  123
  124
  125
  126
  127
  128
  129
  130
  131
  132
  133
  134
  135
  136
  137
  138
  139
  140
  141
  142
  143
  144
  145
; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
; RUN: llc < %s -mtriple=aarch64-unknown-unknown | FileCheck %s

; Check that under certain conditions we can factor out a rotate
; from the following idioms:
;   (a*c0) >> s1 | (a*c1)
;   (a/c0) << s1 | (a/c1)
; This targets cases where instcombine has folded a shl/srl/mul/udiv
; with one of the shifts from the rotate idiom

define i64 @ror_extract_shl(i64 %i) nounwind {
; CHECK-LABEL: ror_extract_shl:
; CHECK:       // %bb.0:
; CHECK-NEXT:    lsl x8, x0, #3
; CHECK-NEXT:    ror x0, x8, #57
; CHECK-NEXT:    ret
  %lhs_mul = shl i64 %i, 3
  %rhs_mul = shl i64 %i, 10
  %lhs_shift = lshr i64 %lhs_mul, 57
  %out = or i64 %lhs_shift, %rhs_mul
  ret i64 %out
}

define i32 @ror_extract_shrl(i32 %i) nounwind {
; CHECK-LABEL: ror_extract_shrl:
; CHECK:       // %bb.0:
; CHECK-NEXT:    lsr w8, w0, #3
; CHECK-NEXT:    ror w0, w8, #4
; CHECK-NEXT:    ret
  %lhs_div = lshr i32 %i, 7
  %rhs_div = lshr i32 %i, 3
  %rhs_shift = shl i32 %rhs_div, 28
  %out = or i32 %lhs_div, %rhs_shift
  ret i32 %out
}

define i32 @ror_extract_mul(i32 %i) nounwind {
; CHECK-LABEL: ror_extract_mul:
; CHECK:       // %bb.0:
; CHECK-NEXT:    add w8, w0, w0, lsl #3
; CHECK-NEXT:    ror w0, w8, #25
; CHECK-NEXT:    ret
  %lhs_mul = mul i32 %i, 9
  %rhs_mul = mul i32 %i, 1152
  %lhs_shift = lshr i32 %lhs_mul, 25
  %out = or i32 %lhs_shift, %rhs_mul
  ret i32 %out
}

define i64 @ror_extract_udiv(i64 %i) nounwind {
; CHECK-LABEL: ror_extract_udiv:
; CHECK:       // %bb.0:
; CHECK-NEXT:    mov x8, #-6148914691236517206
; CHECK-NEXT:    movk x8, #43691
; CHECK-NEXT:    umulh x8, x0, x8
; CHECK-NEXT:    lsr x8, x8, #1
; CHECK-NEXT:    ror x0, x8, #4
; CHECK-NEXT:    ret
  %lhs_div = udiv i64 %i, 3
  %rhs_div = udiv i64 %i, 48
  %lhs_shift = shl i64 %lhs_div, 60
  %out = or i64 %lhs_shift, %rhs_div
  ret i64 %out
}

define i64 @ror_extract_mul_with_mask(i64 %i) nounwind {
; CHECK-LABEL: ror_extract_mul_with_mask:
; CHECK:       // %bb.0:
; CHECK-NEXT:    add x8, x0, x0, lsl #3
; CHECK-NEXT:    ror x8, x8, #57
; CHECK-NEXT:    and x0, x8, #0xff
; CHECK-NEXT:    ret
  %lhs_mul = mul i64 %i, 1152
  %rhs_mul = mul i64 %i, 9
  %lhs_and = and i64 %lhs_mul, 160
  %rhs_shift = lshr i64 %rhs_mul, 57
  %out = or i64 %lhs_and, %rhs_shift
  ret i64 %out
}

; Result would undershift
define i64 @no_extract_shl(i64 %i) nounwind {
; CHECK-LABEL: no_extract_shl:
; CHECK:       // %bb.0:
; CHECK-NEXT:    lsl x8, x0, #10
; CHECK-NEXT:    bfxil x8, x0, #52, #7
; CHECK-NEXT:    mov x0, x8
; CHECK-NEXT:    ret
  %lhs_mul = shl i64 %i, 5
  %rhs_mul = shl i64 %i, 10
  %lhs_shift = lshr i64 %lhs_mul, 57
  %out = or i64 %lhs_shift, %rhs_mul
  ret i64 %out
}

; Result would overshift
define i32 @no_extract_shrl(i32 %i) nounwind {
; CHECK-LABEL: no_extract_shrl:
; CHECK:       // %bb.0:
; CHECK-NEXT:    lsr w8, w0, #3
; CHECK-NEXT:    lsr w0, w0, #9
; CHECK-NEXT:    bfi w0, w8, #28, #4
; CHECK-NEXT:    ret
  %lhs_div = lshr i32 %i, 3
  %rhs_div = lshr i32 %i, 9
  %lhs_shift = shl i32 %lhs_div, 28
  %out = or i32 %lhs_shift, %rhs_div
  ret i32 %out
}

; Can factor 128 from 2304, but result is 18 instead of 9
define i64 @no_extract_mul(i64 %i) nounwind {
; CHECK-LABEL: no_extract_mul:
; CHECK:       // %bb.0:
; CHECK-NEXT:    add x8, x0, x0, lsl #3
; CHECK-NEXT:    lsr x0, x8, #57
; CHECK-NEXT:    bfi x0, x8, #8, #56
; CHECK-NEXT:    ret
  %lhs_mul = mul i64 %i, 2304
  %rhs_mul = mul i64 %i, 9
  %rhs_shift = lshr i64 %rhs_mul, 57
  %out = or i64 %lhs_mul, %rhs_shift
  ret i64 %out
}

; Can't evenly factor 16 from 49
define i32 @no_extract_udiv(i32 %i) nounwind {
; CHECK-LABEL: no_extract_udiv:
; CHECK:       // %bb.0:
; CHECK-NEXT:    mov w8, #43691
; CHECK-NEXT:    mov w9, #33437
; CHECK-NEXT:    movk w8, #43690, lsl #16
; CHECK-NEXT:    movk w9, #21399, lsl #16
; CHECK-NEXT:    umull x8, w0, w8
; CHECK-NEXT:    umull x9, w0, w9
; CHECK-NEXT:    lsr x8, x8, #33
; CHECK-NEXT:    lsr x9, x9, #32
; CHECK-NEXT:    extr w0, w8, w9, #4
; CHECK-NEXT:    ret
  %lhs_div = udiv i32 %i, 3
  %rhs_div = udiv i32 %i, 49
  %lhs_shift = shl i32 %lhs_div, 28
  %out = or i32 %lhs_shift, %rhs_div
  ret i32 %out
}