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      1 ; RUN: opt < %s -indvars -S | FileCheck %s
      2 ;
      3 ; Make sure that indvars isn't inserting canonical IVs.
      4 ; This is kinda hard to do until linear function test replacement is removed.
      5 
      6 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
      7 
      8 define i32 @sum(i32* %arr, i32 %n) nounwind {
      9 entry:
     10   %precond = icmp slt i32 0, %n
     11   br i1 %precond, label %ph, label %return
     12 
     13 ph:
     14   br label %loop
     15 
     16 ; CHECK: loop:
     17 ;
     18 ; We should only have 2 IVs.
     19 ; CHECK: phi
     20 ; CHECK: phi
     21 ; CHECK-NOT: phi
     22 ;
     23 ; sext should be eliminated while preserving gep inboundsness.
     24 ; CHECK-NOT: sext
     25 ; CHECK: getelementptr inbounds
     26 ; CHECK: exit:
     27 loop:
     28   %i.02 = phi i32 [ 0, %ph ], [ %iinc, %loop ]
     29   %s.01 = phi i32 [ 0, %ph ], [ %sinc, %loop ]
     30   %ofs = sext i32 %i.02 to i64
     31   %adr = getelementptr inbounds i32* %arr, i64 %ofs
     32   %val = load i32* %adr
     33   %sinc = add nsw i32 %s.01, %val
     34   %iinc = add nsw i32 %i.02, 1
     35   %cond = icmp slt i32 %iinc, %n
     36   br i1 %cond, label %loop, label %exit
     37 
     38 exit:
     39   %s.lcssa = phi i32 [ %sinc, %loop ]
     40   br label %return
     41 
     42 return:
     43   %s.0.lcssa = phi i32 [ %s.lcssa, %exit ], [ 0, %entry ]
     44   ret i32 %s.0.lcssa
     45 }
     46 
     47 define i64 @suml(i32* %arr, i32 %n) nounwind {
     48 entry:
     49   %precond = icmp slt i32 0, %n
     50   br i1 %precond, label %ph, label %return
     51 
     52 ph:
     53   br label %loop
     54 
     55 ; CHECK: loop:
     56 ;
     57 ; We should only have 2 IVs.
     58 ; CHECK: phi
     59 ; CHECK: phi
     60 ; CHECK-NOT: phi
     61 ;
     62 ; %ofs sext should be eliminated while preserving gep inboundsness.
     63 ; CHECK-NOT: sext
     64 ; CHECK: getelementptr inbounds
     65 ; %vall sext should obviously not be eliminated
     66 ; CHECK: sext
     67 ; CHECK: exit:
     68 loop:
     69   %i.02 = phi i32 [ 0, %ph ], [ %iinc, %loop ]
     70   %s.01 = phi i64 [ 0, %ph ], [ %sinc, %loop ]
     71   %ofs = sext i32 %i.02 to i64
     72   %adr = getelementptr inbounds i32* %arr, i64 %ofs
     73   %val = load i32* %adr
     74   %vall = sext i32 %val to i64
     75   %sinc = add nsw i64 %s.01, %vall
     76   %iinc = add nsw i32 %i.02, 1
     77   %cond = icmp slt i32 %iinc, %n
     78   br i1 %cond, label %loop, label %exit
     79 
     80 exit:
     81   %s.lcssa = phi i64 [ %sinc, %loop ]
     82   br label %return
     83 
     84 return:
     85   %s.0.lcssa = phi i64 [ %s.lcssa, %exit ], [ 0, %entry ]
     86   ret i64 %s.0.lcssa
     87 }
     88 
     89 define void @outofbounds(i32* %first, i32* %last, i32 %idx) nounwind {
     90   %precond = icmp ne i32* %first, %last
     91   br i1 %precond, label %ph, label %return
     92 
     93 ; CHECK: ph:
     94 ; It's not indvars' job to perform LICM on %ofs
     95 ; CHECK-NOT: sext
     96 ph:
     97   br label %loop
     98 
     99 ; CHECK: loop:
    100 ;
    101 ; Preserve exactly one pointer type IV.
    102 ; CHECK: phi i32*
    103 ; CHECK-NOT: phi
    104 ;
    105 ; Don't create any extra adds.
    106 ; CHECK-NOT: add
    107 ;
    108 ; Preserve gep inboundsness, and don't factor it.
    109 ; CHECK: getelementptr inbounds i32* %ptriv, i32 1
    110 ; CHECK-NOT: add
    111 ; CHECK: exit:
    112 loop:
    113   %ptriv = phi i32* [ %first, %ph ], [ %ptrpost, %loop ]
    114   %ofs = sext i32 %idx to i64
    115   %adr = getelementptr inbounds i32* %ptriv, i64 %ofs
    116   store i32 3, i32* %adr
    117   %ptrpost = getelementptr inbounds i32* %ptriv, i32 1
    118   %cond = icmp ne i32* %ptrpost, %last
    119   br i1 %cond, label %loop, label %exit
    120 
    121 exit:
    122   br label %return
    123 
    124 return:
    125   ret void
    126 }
    127 
    128 %structI = type { i32 }
    129 
    130 define void @bitcastiv(i32 %start, i32 %limit, i32 %step, %structI* %base)
    131 nounwind
    132 {
    133 entry:
    134   br label %loop
    135 
    136 ; CHECK: loop:
    137 ;
    138 ; Preserve casts
    139 ; CHECK: phi i32
    140 ; CHECK: bitcast
    141 ; CHECK: getelementptr
    142 ; CHECK: exit:
    143 loop:
    144   %iv = phi i32 [%start, %entry], [%next, %loop]
    145   %p = phi %structI* [%base, %entry], [%pinc, %loop]
    146   %adr = getelementptr %structI* %p, i32 0, i32 0
    147   store i32 3, i32* %adr
    148   %pp = bitcast %structI* %p to i32*
    149   store i32 4, i32* %pp
    150   %pinc = getelementptr %structI* %p, i32 1
    151   %next = add i32 %iv, 1
    152   %cond = icmp ne i32 %next, %limit
    153   br i1 %cond, label %loop, label %exit
    154 
    155 exit:
    156   ret void
    157 }
    158 
    159 define void @maxvisitor(i32 %limit, i32* %base) nounwind {
    160 entry:
    161  br label %loop
    162 
    163 ; Test inserting a truncate at a phi use.
    164 ;
    165 ; CHECK: loop:
    166 ; CHECK: phi i64
    167 ; CHECK: trunc
    168 ; CHECK: exit:
    169 loop:
    170   %idx = phi i32 [ 0, %entry ], [ %idx.next, %loop.inc ]
    171   %max = phi i32 [ 0, %entry ], [ %max.next, %loop.inc ]
    172   %idxprom = sext i32 %idx to i64
    173   %adr = getelementptr inbounds i32* %base, i64 %idxprom
    174   %val = load i32* %adr
    175   %cmp19 = icmp sgt i32 %val, %max
    176   br i1 %cmp19, label %if.then, label %if.else
    177 
    178 if.then:
    179   br label %loop.inc
    180 
    181 if.else:
    182   br label %loop.inc
    183 
    184 loop.inc:
    185   %max.next = phi i32 [ %idx, %if.then ], [ %max, %if.else ]
    186   %idx.next = add nsw i32 %idx, 1
    187   %cmp = icmp slt i32 %idx.next, %limit
    188   br i1 %cmp, label %loop, label %exit
    189 
    190 exit:
    191   ret void
    192 }
    193 
    194 define void @identityphi(i32 %limit) nounwind {
    195 entry:
    196   br label %loop
    197 
    198 ; Test an edge case of removing an identity phi that directly feeds
    199 ; back to the loop iv.
    200 ;
    201 ; CHECK: loop:
    202 ; CHECK: phi i32
    203 ; CHECK-NOT: phi
    204 ; CHECK: exit:
    205 loop:
    206   %iv = phi i32 [ 0, %entry], [ %iv.next, %control ]
    207   br i1 undef, label %if.then, label %control
    208 
    209 if.then:
    210   br label %control
    211 
    212 control:
    213   %iv.next = phi i32 [ %iv, %loop ], [ undef, %if.then ]
    214   %cmp = icmp slt i32 %iv.next, %limit
    215   br i1 %cmp, label %loop, label %exit
    216 
    217 exit:
    218   ret void
    219 }
    220 
    221 define i64 @cloneOr(i32 %limit, i64* %base) nounwind {
    222 entry:
    223   ; ensure that the loop can't overflow
    224   %halfLim = ashr i32 %limit, 2
    225   br label %loop
    226 
    227 ; Test cloning an or, which is not an OverflowBinaryOperator.
    228 ;
    229 ; CHECK: loop:
    230 ; CHECK: phi i64
    231 ; CHECK-NOT: sext
    232 ; CHECK: or i64
    233 ; CHECK: exit:
    234 loop:
    235   %iv = phi i32 [ 0, %entry], [ %iv.next, %loop ]
    236   %t1 = sext i32 %iv to i64
    237   %adr = getelementptr i64* %base, i64 %t1
    238   %val = load i64* %adr
    239   %t2 = or i32 %iv, 1
    240   %t3 = sext i32 %t2 to i64
    241   %iv.next = add i32 %iv, 2
    242   %cmp = icmp slt i32 %iv.next, %halfLim
    243   br i1 %cmp, label %loop, label %exit
    244 
    245 exit:
    246   %result = and i64 %val, %t3
    247   ret i64 %result
    248 }
    249 
    250 ; The i induction variable looks like a wrap-around, but it really is just
    251 ; a simple affine IV.  Make sure that indvars simplifies through.
    252 define i32 @indirectRecurrence() nounwind {
    253 entry:
    254   br label %loop
    255 
    256 ; ReplaceLoopExitValue should fold the return value to constant 9.
    257 ; CHECK: loop:
    258 ; CHECK: phi i32
    259 ; CHECK: ret i32 9
    260 loop:
    261   %j.0 = phi i32 [ 1, %entry ], [ %j.next, %cond_true ]
    262   %i.0 = phi i32 [ 0, %entry ], [ %j.0, %cond_true ]
    263   %tmp = icmp ne i32 %j.0, 10
    264   br i1 %tmp, label %cond_true, label %return
    265 
    266 cond_true:
    267   %j.next = add i32 %j.0, 1
    268   br label %loop
    269 
    270 return:
    271   ret i32 %i.0
    272 }
    273 
    274 ; Eliminate the congruent phis j, k, and l.
    275 ; Eliminate the redundant IV increments k.next and l.next.
    276 ; Two phis should remain, one starting at %init, and one at %init1.
    277 ; Two increments should remain, one by %step and one by %step1.
    278 ; CHECK: loop:
    279 ; CHECK: phi i32
    280 ; CHECK: phi i32
    281 ; CHECK-NOT: phi
    282 ; CHECK: add i32
    283 ; CHECK: add i32
    284 ; CHECK: add i32
    285 ; CHECK-NOT: add
    286 ; CHECK: return:
    287 ;
    288 ; Five live-outs should remain.
    289 ; CHECK: lcssa = phi
    290 ; CHECK: lcssa = phi
    291 ; CHECK: lcssa = phi
    292 ; CHECK: lcssa = phi
    293 ; CHECK: lcssa = phi
    294 ; CHECK-NOT: phi
    295 ; CHECK: ret
    296 define i32 @isomorphic(i32 %init, i32 %step, i32 %lim) nounwind {
    297 entry:
    298   %step1 = add i32 %step, 1
    299   %init1 = add i32 %init, %step1
    300   %l.0 = sub i32 %init1, %step1
    301   br label %loop
    302 
    303 loop:
    304   %ii = phi i32 [ %init1, %entry ], [ %ii.next, %loop ]
    305   %i = phi i32 [ %init, %entry ], [ %ii, %loop ]
    306   %j = phi i32 [ %init, %entry ], [ %j.next, %loop ]
    307   %k = phi i32 [ %init1, %entry ], [ %k.next, %loop ]
    308   %l = phi i32 [ %l.0, %entry ], [ %l.next, %loop ]
    309   %ii.next = add i32 %ii, %step1
    310   %j.next = add i32 %j, %step1
    311   %k.next = add i32 %k, %step1
    312   %l.step = add i32 %l, %step
    313   %l.next = add i32 %l.step, 1
    314   %cmp = icmp ne i32 %ii.next, %lim
    315   br i1 %cmp, label %loop, label %return
    316 
    317 return:
    318   %sum1 = add i32 %i, %j.next
    319   %sum2 = add i32 %sum1, %k.next
    320   %sum3 = add i32 %sum1, %l.step
    321   %sum4 = add i32 %sum1, %l.next
    322   ret i32 %sum4
    323 }
    324 
    325 ; Test a GEP IV that is derived from another GEP IV by a nop gep that
    326 ; lowers the type without changing the expression.
    327 %structIF = type { i32, float }
    328 
    329 define void @congruentgepiv(%structIF* %base) nounwind uwtable ssp {
    330 entry:
    331   %first = getelementptr inbounds %structIF* %base, i64 0, i32 0
    332   br label %loop
    333 
    334 ; CHECK: loop:
    335 ; CHECK: phi %structIF*
    336 ; CHECK-NOT: phi
    337 ; CHECK: getelementptr inbounds
    338 ; CHECK-NOT: getelementptr
    339 ; CHECK: exit:
    340 loop:
    341   %ptr.iv = phi %structIF* [ %ptr.inc, %latch ], [ %base, %entry ]
    342   %next = phi i32* [ %next.inc, %latch ], [ %first, %entry ]
    343   store i32 4, i32* %next
    344   br i1 undef, label %latch, label %exit
    345 
    346 latch:                         ; preds = %for.inc50.i
    347   %ptr.inc = getelementptr inbounds %structIF* %ptr.iv, i64 1
    348   %next.inc = getelementptr inbounds %structIF* %ptr.inc, i64 0, i32 0
    349   br label %loop
    350 
    351 exit:
    352   ret void
    353 }
    354 
    355 ; Test a widened IV that is used by a phi on different paths within the loop.
    356 ;
    357 ; CHECK: for.body:
    358 ; CHECK: phi i64
    359 ; CHECK: trunc i64
    360 ; CHECK: if.then:
    361 ; CHECK: for.inc:
    362 ; CHECK: phi i32
    363 ; CHECK: for.end:
    364 define void @phiUsesTrunc() nounwind {
    365 entry:
    366   br i1 undef, label %for.body, label %for.end
    367 
    368 for.body:
    369   %iv = phi i32 [ %inc, %for.inc ], [ 1, %entry ]
    370   br i1 undef, label %if.then, label %if.else
    371 
    372 if.then:
    373   br i1 undef, label %if.then33, label %for.inc
    374 
    375 if.then33:
    376   br label %for.inc
    377 
    378 if.else:
    379   br i1 undef, label %if.then97, label %for.inc
    380 
    381 if.then97:
    382   %idxprom100 = sext i32 %iv to i64
    383   br label %for.inc
    384 
    385 for.inc:
    386   %kmin.1 = phi i32 [ %iv, %if.then33 ], [ 0, %if.then ], [ %iv, %if.then97 ], [ 0, %if.else ]
    387   %inc = add nsw i32 %iv, 1
    388   br i1 undef, label %for.body, label %for.end
    389 
    390 for.end:
    391   ret void
    392 }
    393