llvm/test/Transforms/InstCombine/variable-signext-of-variable-high-bit-extraction.ll

   1 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
   2 ; RUN: opt < %s -passes=instcombine -S | FileCheck %s
   3
   4 declare void @use16(i16)
   5 declare void @use32(i32)
   6 declare void @use64(i64)
   7
   8 define i32 @t0(i64 %data, i32 %nbits) {
   9 ; CHECK-LABEL: @t0(
  10 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
  11 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
  12 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
  13 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
  14 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
  15 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
  16 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
  17 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
  18 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
  19 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
  20 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr i64 [[DATA]], [[SKIP_HIGH_WIDE]]
  21 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = trunc i64 [[TMP1]] to i32
  22 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
  23 ;
  24   %skip_high = sub i32 64, %nbits
  25   call void @use32(i32 %skip_high)
  26   %skip_high_wide = zext i32 %skip_high to i64
  27   call void @use64(i64 %skip_high_wide)
  28   %extracted = lshr i64 %data, %skip_high_wide
  29   call void @use64(i64 %extracted)
  30   %extracted_narrow = trunc i64 %extracted to i32
  31   call void @use32(i32 %extracted_narrow)
  32   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
  33   call void @use32(i32 %num_high_bits_to_smear_narrow)
  34   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
  35   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
  36   ret i32 %signextended
  37 }
  38 define i32 @t0_zext_of_nbits(i64 %data, i8 %nbits_narrow) {
  39 ; CHECK-LABEL: @t0_zext_of_nbits(
  40 ; CHECK-NEXT:    [[NBITS:%.*]] = zext i8 [[NBITS_NARROW:%.*]] to i16
  41 ; CHECK-NEXT:    call void @use16(i16 [[NBITS]])
  42 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub nsw i16 64, [[NBITS]]
  43 ; CHECK-NEXT:    call void @use16(i16 [[SKIP_HIGH]])
  44 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i16 [[SKIP_HIGH]] to i64
  45 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
  46 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
  47 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
  48 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
  49 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
  50 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW_NARROW:%.*]] = sub nsw i16 32, [[NBITS]]
  51 ; CHECK-NEXT:    call void @use16(i16 [[NUM_HIGH_BITS_TO_SMEAR_NARROW_NARROW]])
  52 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = zext i16 [[NUM_HIGH_BITS_TO_SMEAR_NARROW_NARROW]] to i32
  53 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
  54 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr i64 [[DATA]], [[SKIP_HIGH_WIDE]]
  55 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = trunc i64 [[TMP1]] to i32
  56 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
  57 ;
  58   %nbits = zext i8 %nbits_narrow to i16
  59   call void @use16(i16 %nbits)
  60   %skip_high = sub i16 64, %nbits
  61   call void @use16(i16 %skip_high)
  62   %skip_high_wide = zext i16 %skip_high to i64
  63   call void @use64(i64 %skip_high_wide)
  64   %extracted = lshr i64 %data, %skip_high_wide
  65   call void @use64(i64 %extracted)
  66   %extracted_narrow = trunc i64 %extracted to i32
  67   call void @use32(i32 %extracted_narrow)
  68   %num_high_bits_to_smear_narrow_narrow = sub i16 32, %nbits
  69   call void @use16(i16 %num_high_bits_to_smear_narrow_narrow)
  70   %num_high_bits_to_smear_narrow = zext i16 %num_high_bits_to_smear_narrow_narrow to i32
  71   call void @use32(i32 %num_high_bits_to_smear_narrow)
  72   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
  73   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
  74   ret i32 %signextended
  75 }
  76 define i32 @t0_exact(i64 %data, i32 %nbits) {
  77 ; CHECK-LABEL: @t0_exact(
  78 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
  79 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
  80 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
  81 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
  82 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr exact i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
  83 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
  84 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
  85 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
  86 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
  87 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
  88 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr exact i64 [[DATA]], [[SKIP_HIGH_WIDE]]
  89 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = trunc i64 [[TMP1]] to i32
  90 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
  91 ;
  92   %skip_high = sub i32 64, %nbits
  93   call void @use32(i32 %skip_high)
  94   %skip_high_wide = zext i32 %skip_high to i64
  95   call void @use64(i64 %skip_high_wide)
  96   %extracted = lshr exact i64 %data, %skip_high_wide ; We can preserve `exact`-ness of the original shift.
  97   call void @use64(i64 %extracted)
  98   %extracted_narrow = trunc i64 %extracted to i32
  99   call void @use32(i32 %extracted_narrow)
 100   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 101   call void @use32(i32 %num_high_bits_to_smear_narrow)
 102   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 103   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
 104   ret i32 %signextended
 105 }
 106
 107 define i32 @t1_redundant_sext(i64 %data, i32 %nbits) {
 108 ; CHECK-LABEL: @t1_redundant_sext(
 109 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 110 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 111 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 112 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 113 ; CHECK-NEXT:    [[EXTRACTED_WITH_SIGNEXTENSION:%.*]] = ashr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 114 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED_WITH_SIGNEXTENSION]])
 115 ; CHECK-NEXT:    [[EXTRACTED_WITH_SIGNEXTENSION_NARROW:%.*]] = trunc i64 [[EXTRACTED_WITH_SIGNEXTENSION]] to i32
 116 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_WITH_SIGNEXTENSION_NARROW]])
 117 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 118 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 119 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i32 [[EXTRACTED_WITH_SIGNEXTENSION_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 120 ; CHECK-NEXT:    call void @use32(i32 [[SIGNBIT_POSITIONED]])
 121 ; CHECK-NEXT:    ret i32 [[EXTRACTED_WITH_SIGNEXTENSION_NARROW]]
 122 ;
 123   %skip_high = sub i32 64, %nbits
 124   call void @use32(i32 %skip_high)
 125   %skip_high_wide = zext i32 %skip_high to i64
 126   call void @use64(i64 %skip_high_wide)
 127   %extracted_with_signextension = ashr i64 %data, %skip_high_wide
 128   call void @use64(i64 %extracted_with_signextension)
 129   %extracted_with_signextension_narrow = trunc i64 %extracted_with_signextension to i32 ; this is already the answer.
 130   call void @use32(i32 %extracted_with_signextension_narrow)
 131   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 132   call void @use32(i32 %num_high_bits_to_smear_narrow)
 133   %signbit_positioned = shl i32 %extracted_with_signextension_narrow, %num_high_bits_to_smear_narrow
 134   call void @use32(i32 %signbit_positioned)
 135   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
 136   ret i32 %signextended
 137 }
 138
 139 define i64 @t2_notrunc(i64 %data, i64 %nbits) {
 140 ; CHECK-LABEL: @t2_notrunc(
 141 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i64 64, [[NBITS:%.*]]
 142 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH]])
 143 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH]]
 144 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 145 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR:%.*]] = sub i64 64, [[NBITS]]
 146 ; CHECK-NEXT:    call void @use64(i64 [[NUM_HIGH_BITS_TO_SMEAR]])
 147 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i64 [[EXTRACTED]], [[NUM_HIGH_BITS_TO_SMEAR]]
 148 ; CHECK-NEXT:    call void @use64(i64 [[SIGNBIT_POSITIONED]])
 149 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = ashr i64 [[DATA]], [[SKIP_HIGH]]
 150 ; CHECK-NEXT:    ret i64 [[SIGNEXTENDED]]
 151 ;
 152   %skip_high = sub i64 64, %nbits
 153   call void @use64(i64 %skip_high)
 154   %extracted = lshr i64 %data, %skip_high
 155   call void @use64(i64 %extracted)
 156   %num_high_bits_to_smear = sub i64 64, %nbits
 157   call void @use64(i64 %num_high_bits_to_smear)
 158   %signbit_positioned = shl i64 %extracted, %num_high_bits_to_smear ;
 159   call void @use64(i64 %signbit_positioned)
 160   %signextended = ashr i64 %signbit_positioned, %num_high_bits_to_smear ; can just shift %data itself.
 161   ret i64 %signextended
 162 }
 163
 164 define i64 @t3_notrunc_redundant_sext(i64 %data, i64 %nbits) {
 165 ; CHECK-LABEL: @t3_notrunc_redundant_sext(
 166 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i64 64, [[NBITS:%.*]]
 167 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH]])
 168 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = ashr i64 [[DATA:%.*]], [[SKIP_HIGH]]
 169 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 170 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR:%.*]] = sub i64 64, [[NBITS]]
 171 ; CHECK-NEXT:    call void @use64(i64 [[NUM_HIGH_BITS_TO_SMEAR]])
 172 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i64 [[EXTRACTED]], [[NUM_HIGH_BITS_TO_SMEAR]]
 173 ; CHECK-NEXT:    call void @use64(i64 [[SIGNBIT_POSITIONED]])
 174 ; CHECK-NEXT:    ret i64 [[EXTRACTED]]
 175 ;
 176   %skip_high = sub i64 64, %nbits
 177   call void @use64(i64 %skip_high)
 178   %extracted = ashr i64 %data, %skip_high ; this is already the answer.
 179   call void @use64(i64 %extracted)
 180   %num_high_bits_to_smear = sub i64 64, %nbits
 181   call void @use64(i64 %num_high_bits_to_smear)
 182   %signbit_positioned = shl i64 %extracted, %num_high_bits_to_smear
 183   call void @use64(i64 %signbit_positioned)
 184   %signextended = ashr i64 %signbit_positioned, %num_high_bits_to_smear
 185   ret i64 %signextended
 186 }
 187
 188 define <2 x i32> @t4_vec(<2 x i64> %data, <2 x i32> %nbits) {
 189 ; CHECK-LABEL: @t4_vec(
 190 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub <2 x i32> splat (i32 64), [[NBITS:%.*]]
 191 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext nneg <2 x i32> [[SKIP_HIGH]] to <2 x i64>
 192 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr <2 x i64> [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 193 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = trunc <2 x i64> [[TMP1]] to <2 x i32>
 194 ; CHECK-NEXT:    ret <2 x i32> [[SIGNEXTENDED]]
 195 ;
 196   %skip_high = sub <2 x i32> <i32 64, i32 64>, %nbits
 197   %skip_high_wide = zext <2 x i32> %skip_high to <2 x i64>
 198   %extracted = lshr <2 x i64> %data, %skip_high_wide
 199   %extracted_narrow = trunc <2 x i64> %extracted to <2 x i32>
 200   %num_high_bits_to_smear_narrow = sub <2 x i32> <i32 32, i32 32>, %nbits
 201   %signbit_positioned = shl <2 x i32> %extracted_narrow, %num_high_bits_to_smear_narrow
 202   %signextended = ashr <2 x i32> %signbit_positioned, %num_high_bits_to_smear_narrow
 203   ret <2 x i32> %signextended
 204 }
 205
 206 define <3 x i32> @t5_vec_poison(<3 x i64> %data, <3 x i32> %nbits) {
 207 ; CHECK-LABEL: @t5_vec_poison(
 208 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub <3 x i32> <i32 64, i32 64, i32 poison>, [[NBITS:%.*]]
 209 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext nneg <3 x i32> [[SKIP_HIGH]] to <3 x i64>
 210 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr <3 x i64> [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 211 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = trunc <3 x i64> [[TMP1]] to <3 x i32>
 212 ; CHECK-NEXT:    ret <3 x i32> [[SIGNEXTENDED]]
 213 ;
 214   %skip_high = sub <3 x i32> <i32 64, i32 64, i32 poison>, %nbits
 215   %skip_high_wide = zext <3 x i32> %skip_high to <3 x i64>
 216   %extracted = lshr <3 x i64> %data, %skip_high_wide
 217   %extracted_narrow = trunc <3 x i64> %extracted to <3 x i32>
 218   %num_high_bits_to_smear_narrow0 = sub <3 x i32> <i32 32, i32 32, i32 poison>, %nbits
 219   %num_high_bits_to_smear_narrow1 = sub <3 x i32> <i32 poison, i32 32, i32 32>, %nbits
 220   %signbit_positioned = shl <3 x i32> %extracted_narrow, %num_high_bits_to_smear_narrow0
 221   %signextended = ashr <3 x i32> %signbit_positioned, %num_high_bits_to_smear_narrow1
 222   ret <3 x i32> %signextended
 223 }
 224
 225 ; Extra-uses
 226 define i32 @t6_extrause_good0(i64 %data, i32 %nbits) {
 227 ; CHECK-LABEL: @t6_extrause_good0(
 228 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 229 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 230 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 231 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 232 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 233 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 234 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 235 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 236 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 237 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 238 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr i64 [[DATA]], [[SKIP_HIGH_WIDE]]
 239 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = trunc i64 [[TMP1]] to i32
 240 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
 241 ;
 242   %skip_high = sub i32 64, %nbits
 243   call void @use32(i32 %skip_high)
 244   %skip_high_wide = zext i32 %skip_high to i64
 245   call void @use64(i64 %skip_high_wide)
 246   %extracted = lshr i64 %data, %skip_high_wide
 247   call void @use64(i64 %extracted)
 248   %extracted_narrow = trunc i64 %extracted to i32
 249   call void @use32(i32 %extracted_narrow)
 250   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 251   call void @use32(i32 %num_high_bits_to_smear_narrow)
 252   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow ; will go away
 253   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
 254   ret i32 %signextended
 255 }
 256 define i32 @t7_extrause_good1(i64 %data, i32 %nbits) {
 257 ; CHECK-LABEL: @t7_extrause_good1(
 258 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 259 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 260 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 261 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 262 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 263 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 264 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 265 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 266 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW0:%.*]] = sub i32 32, [[NBITS]]
 267 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW0]])
 268 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW0]]
 269 ; CHECK-NEXT:    call void @use32(i32 [[SIGNBIT_POSITIONED]])
 270 ; CHECK-NEXT:    [[TMP1:%.*]] = ashr i64 [[DATA]], [[SKIP_HIGH_WIDE]]
 271 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = trunc i64 [[TMP1]] to i32
 272 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
 273 ;
 274   %skip_high = sub i32 64, %nbits
 275   call void @use32(i32 %skip_high)
 276   %skip_high_wide = zext i32 %skip_high to i64
 277   call void @use64(i64 %skip_high_wide)
 278   %extracted = lshr i64 %data, %skip_high_wide
 279   call void @use64(i64 %extracted)
 280   %extracted_narrow = trunc i64 %extracted to i32
 281   call void @use32(i32 %extracted_narrow)
 282   %num_high_bits_to_smear_narrow0 = sub i32 32, %nbits
 283   call void @use32(i32 %num_high_bits_to_smear_narrow0)
 284   %num_high_bits_to_smear_narrow1 = sub i32 32, %nbits ; will go away.
 285   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow0
 286   call void @use32(i32 %signbit_positioned)
 287   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow1
 288   ret i32 %signextended
 289 }
 290 define i32 @n8_extrause_bad(i64 %data, i32 %nbits) {
 291 ; CHECK-LABEL: @n8_extrause_bad(
 292 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 293 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 294 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 295 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 296 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 297 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 298 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 299 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 300 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 301 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 302 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 303 ; CHECK-NEXT:    call void @use32(i32 [[SIGNBIT_POSITIONED]])
 304 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = ashr exact i32 [[SIGNBIT_POSITIONED]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 305 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
 306 ;
 307   %skip_high = sub i32 64, %nbits
 308   call void @use32(i32 %skip_high)
 309   %skip_high_wide = zext i32 %skip_high to i64
 310   call void @use64(i64 %skip_high_wide)
 311   %extracted = lshr i64 %data, %skip_high_wide
 312   call void @use64(i64 %extracted)
 313   %extracted_narrow = trunc i64 %extracted to i32
 314   call void @use32(i32 %extracted_narrow)
 315   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 316   call void @use32(i32 %num_high_bits_to_smear_narrow)
 317   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 318   call void @use32(i32 %signbit_positioned)
 319   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow ; neither of operands will go away.
 320   ret i32 %signextended
 321 }
 322
 323 ; Negative tests
 324 define i32 @n9(i64 %data, i32 %nbits) {
 325 ; CHECK-LABEL: @n9(
 326 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 63, [[NBITS:%.*]]
 327 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 328 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 329 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 330 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 331 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 332 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 333 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 334 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 335 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 336 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 337 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = ashr exact i32 [[SIGNBIT_POSITIONED]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 338 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
 339 ;
 340   %skip_high = sub i32 63, %nbits ; not 64
 341   call void @use32(i32 %skip_high)
 342   %skip_high_wide = zext i32 %skip_high to i64
 343   call void @use64(i64 %skip_high_wide)
 344   %extracted = lshr i64 %data, %skip_high_wide
 345   call void @use64(i64 %extracted)
 346   %extracted_narrow = trunc i64 %extracted to i32
 347   call void @use32(i32 %extracted_narrow)
 348   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 349   call void @use32(i32 %num_high_bits_to_smear_narrow)
 350   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 351   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
 352   ret i32 %signextended
 353 }
 354
 355 define i32 @n10(i64 %data, i32 %nbits) {
 356 ; CHECK-LABEL: @n10(
 357 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 358 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 359 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 360 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 361 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 362 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 363 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 364 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 365 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 31, [[NBITS]]
 366 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 367 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 368 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = ashr exact i32 [[SIGNBIT_POSITIONED]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 369 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
 370 ;
 371   %skip_high = sub i32 64, %nbits
 372   call void @use32(i32 %skip_high)
 373   %skip_high_wide = zext i32 %skip_high to i64
 374   call void @use64(i64 %skip_high_wide)
 375   %extracted = lshr i64 %data, %skip_high_wide
 376   call void @use64(i64 %extracted)
 377   %extracted_narrow = trunc i64 %extracted to i32
 378   call void @use32(i32 %extracted_narrow)
 379   %num_high_bits_to_smear_narrow = sub i32 31, %nbits ; not 32
 380   call void @use32(i32 %num_high_bits_to_smear_narrow)
 381   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 382   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
 383   ret i32 %signextended
 384 }
 385
 386 define i32 @n11(i64 %data, i32 %nbits1, i32 %nbits2) {
 387 ; CHECK-LABEL: @n11(
 388 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS1:%.*]]
 389 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 390 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 391 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 392 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 393 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 394 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 395 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 396 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS2:%.*]]
 397 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 398 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 399 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = ashr exact i32 [[SIGNBIT_POSITIONED]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 400 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
 401 ;
 402   %skip_high = sub i32 64, %nbits1 ; not %nbits2
 403   call void @use32(i32 %skip_high)
 404   %skip_high_wide = zext i32 %skip_high to i64
 405   call void @use64(i64 %skip_high_wide)
 406   %extracted = lshr i64 %data, %skip_high_wide
 407   call void @use64(i64 %extracted)
 408   %extracted_narrow = trunc i64 %extracted to i32
 409   call void @use32(i32 %extracted_narrow)
 410   %num_high_bits_to_smear_narrow = sub i32 32, %nbits2 ; not %nbits1
 411   call void @use32(i32 %num_high_bits_to_smear_narrow)
 412   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 413   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow
 414   ret i32 %signextended
 415 }
 416
 417 define i32 @n12(i64 %data, i32 %nbits1, i32 %nbits2) {
 418 ; CHECK-LABEL: @n12(
 419 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS1:%.*]]
 420 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 421 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 422 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 423 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 424 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 425 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 426 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 427 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW1:%.*]] = sub i32 32, [[NBITS1]]
 428 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW2:%.*]] = sub i32 32, [[NBITS2:%.*]]
 429 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW1]])
 430 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW2]])
 431 ; CHECK-NEXT:    [[SIGNBIT_POSITIONED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW1]]
 432 ; CHECK-NEXT:    [[SIGNEXTENDED:%.*]] = ashr i32 [[SIGNBIT_POSITIONED]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW2]]
 433 ; CHECK-NEXT:    ret i32 [[SIGNEXTENDED]]
 434 ;
 435   %skip_high = sub i32 64, %nbits1
 436   call void @use32(i32 %skip_high)
 437   %skip_high_wide = zext i32 %skip_high to i64
 438   call void @use64(i64 %skip_high_wide)
 439   %extracted = lshr i64 %data, %skip_high_wide
 440   call void @use64(i64 %extracted)
 441   %extracted_narrow = trunc i64 %extracted to i32
 442   call void @use32(i32 %extracted_narrow)
 443   %num_high_bits_to_smear_narrow1 = sub i32 32, %nbits1 ; not %nbits2
 444   %num_high_bits_to_smear_narrow2 = sub i32 32, %nbits2 ; not %nbits1
 445   call void @use32(i32 %num_high_bits_to_smear_narrow1)
 446   call void @use32(i32 %num_high_bits_to_smear_narrow2)
 447   %signbit_positioned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow1
 448   %signextended = ashr i32 %signbit_positioned, %num_high_bits_to_smear_narrow2
 449   ret i32 %signextended
 450 }
 451
 452 define i32 @n13(i64 %data, i32 %nbits) {
 453 ; CHECK-LABEL: @n13(
 454 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 455 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 456 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 457 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 458 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 459 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 460 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 461 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 462 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 463 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 464 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 -1, [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 465 ; CHECK-NEXT:    [[RES:%.*]] = and i32 [[TMP1]], [[EXTRACTED_NARROW]]
 466 ; CHECK-NEXT:    ret i32 [[RES]]
 467 ;
 468   %skip_high = sub i32 64, %nbits
 469   call void @use32(i32 %skip_high)
 470   %skip_high_wide = zext i32 %skip_high to i64
 471   call void @use64(i64 %skip_high_wide)
 472   %extracted = lshr i64 %data, %skip_high_wide
 473   call void @use64(i64 %extracted)
 474   %extracted_narrow = trunc i64 %extracted to i32
 475   call void @use32(i32 %extracted_narrow)
 476   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 477   call void @use32(i32 %num_high_bits_to_smear_narrow)
 478   %highbits_cleaned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 479   %res = lshr i32 %highbits_cleaned, %num_high_bits_to_smear_narrow ; not ashr
 480   ret i32 %res
 481 }
 482 define i32 @n13_extrause(i64 %data, i32 %nbits) {
 483 ; CHECK-LABEL: @n13_extrause(
 484 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 485 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 486 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 487 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 488 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = lshr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 489 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 490 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 491 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 492 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 493 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 494 ; CHECK-NEXT:    [[HIGHBITS_CLEANED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 495 ; CHECK-NEXT:    call void @use32(i32 [[HIGHBITS_CLEANED]])
 496 ; CHECK-NEXT:    [[RES:%.*]] = lshr exact i32 [[HIGHBITS_CLEANED]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 497 ; CHECK-NEXT:    ret i32 [[RES]]
 498 ;
 499   %skip_high = sub i32 64, %nbits
 500   call void @use32(i32 %skip_high)
 501   %skip_high_wide = zext i32 %skip_high to i64
 502   call void @use64(i64 %skip_high_wide)
 503   %extracted = lshr i64 %data, %skip_high_wide
 504   call void @use64(i64 %extracted)
 505   %extracted_narrow = trunc i64 %extracted to i32
 506   call void @use32(i32 %extracted_narrow)
 507   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 508   call void @use32(i32 %num_high_bits_to_smear_narrow)
 509   %highbits_cleaned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 510   call void @use32(i32 %highbits_cleaned)
 511   %res = lshr i32 %highbits_cleaned, %num_high_bits_to_smear_narrow ; not ashr
 512   ret i32 %res
 513 }
 514 define i32 @n14(i64 %data, i32 %nbits) {
 515 ; CHECK-LABEL: @n14(
 516 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 517 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 518 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 519 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 520 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = ashr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 521 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 522 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 523 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 524 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 525 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 526 ; CHECK-NEXT:    [[TMP1:%.*]] = lshr i32 -1, [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 527 ; CHECK-NEXT:    [[RES:%.*]] = and i32 [[TMP1]], [[EXTRACTED_NARROW]]
 528 ; CHECK-NEXT:    ret i32 [[RES]]
 529 ;
 530   %skip_high = sub i32 64, %nbits
 531   call void @use32(i32 %skip_high)
 532   %skip_high_wide = zext i32 %skip_high to i64
 533   call void @use64(i64 %skip_high_wide)
 534   %extracted = ashr i64 %data, %skip_high_wide
 535   call void @use64(i64 %extracted)
 536   %extracted_narrow = trunc i64 %extracted to i32
 537   call void @use32(i32 %extracted_narrow)
 538   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 539   call void @use32(i32 %num_high_bits_to_smear_narrow)
 540   %highbits_cleaned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 541   %res = lshr i32 %highbits_cleaned, %num_high_bits_to_smear_narrow ; not ashr
 542   ret i32 %res
 543 }
 544 define i32 @n14_extrause(i64 %data, i32 %nbits) {
 545 ; CHECK-LABEL: @n14_extrause(
 546 ; CHECK-NEXT:    [[SKIP_HIGH:%.*]] = sub i32 64, [[NBITS:%.*]]
 547 ; CHECK-NEXT:    call void @use32(i32 [[SKIP_HIGH]])
 548 ; CHECK-NEXT:    [[SKIP_HIGH_WIDE:%.*]] = zext i32 [[SKIP_HIGH]] to i64
 549 ; CHECK-NEXT:    call void @use64(i64 [[SKIP_HIGH_WIDE]])
 550 ; CHECK-NEXT:    [[EXTRACTED:%.*]] = ashr i64 [[DATA:%.*]], [[SKIP_HIGH_WIDE]]
 551 ; CHECK-NEXT:    call void @use64(i64 [[EXTRACTED]])
 552 ; CHECK-NEXT:    [[EXTRACTED_NARROW:%.*]] = trunc i64 [[EXTRACTED]] to i32
 553 ; CHECK-NEXT:    call void @use32(i32 [[EXTRACTED_NARROW]])
 554 ; CHECK-NEXT:    [[NUM_HIGH_BITS_TO_SMEAR_NARROW:%.*]] = sub i32 32, [[NBITS]]
 555 ; CHECK-NEXT:    call void @use32(i32 [[NUM_HIGH_BITS_TO_SMEAR_NARROW]])
 556 ; CHECK-NEXT:    [[HIGHBITS_CLEANED:%.*]] = shl i32 [[EXTRACTED_NARROW]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 557 ; CHECK-NEXT:    call void @use32(i32 [[HIGHBITS_CLEANED]])
 558 ; CHECK-NEXT:    [[RES:%.*]] = lshr exact i32 [[HIGHBITS_CLEANED]], [[NUM_HIGH_BITS_TO_SMEAR_NARROW]]
 559 ; CHECK-NEXT:    ret i32 [[RES]]
 560 ;
 561   %skip_high = sub i32 64, %nbits
 562   call void @use32(i32 %skip_high)
 563   %skip_high_wide = zext i32 %skip_high to i64
 564   call void @use64(i64 %skip_high_wide)
 565   %extracted = ashr i64 %data, %skip_high_wide
 566   call void @use64(i64 %extracted)
 567   %extracted_narrow = trunc i64 %extracted to i32
 568   call void @use32(i32 %extracted_narrow)
 569   %num_high_bits_to_smear_narrow = sub i32 32, %nbits
 570   call void @use32(i32 %num_high_bits_to_smear_narrow)
 571   %highbits_cleaned = shl i32 %extracted_narrow, %num_high_bits_to_smear_narrow
 572   call void @use32(i32 %highbits_cleaned)
 573   %res = lshr i32 %highbits_cleaned, %num_high_bits_to_smear_narrow ; not ashr
 574   ret i32 %res
 575 }