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      1 ; RUN: opt < %s -sroa -S | FileCheck %s
      2 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n8:16:32:64"
      3 
      4 define i32 @test1() {
      5 ; CHECK-LABEL: @test1(
      6 entry:
      7 	%a = alloca [2 x i32]
      8 ; CHECK-NOT: alloca
      9 
     10   %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0
     11   %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1
     12 	store i32 0, i32* %a0
     13 	store i32 1, i32* %a1
     14 	%v0 = load i32, i32* %a0
     15 	%v1 = load i32, i32* %a1
     16 ; CHECK-NOT: store
     17 ; CHECK-NOT: load
     18 
     19 	%cond = icmp sle i32 %v0, %v1
     20 	br i1 %cond, label %then, label %exit
     21 
     22 then:
     23 	br label %exit
     24 
     25 exit:
     26 	%phi = phi i32* [ %a1, %then ], [ %a0, %entry ]
     27 ; CHECK: phi i32 [ 1, %{{.*}} ], [ 0, %{{.*}} ]
     28 
     29 	%result = load i32, i32* %phi
     30 	ret i32 %result
     31 }
     32 
     33 define i32 @test2() {
     34 ; CHECK-LABEL: @test2(
     35 entry:
     36 	%a = alloca [2 x i32]
     37 ; CHECK-NOT: alloca
     38 
     39   %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0
     40   %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1
     41 	store i32 0, i32* %a0
     42 	store i32 1, i32* %a1
     43 	%v0 = load i32, i32* %a0
     44 	%v1 = load i32, i32* %a1
     45 ; CHECK-NOT: store
     46 ; CHECK-NOT: load
     47 
     48 	%cond = icmp sle i32 %v0, %v1
     49 	%select = select i1 %cond, i32* %a1, i32* %a0
     50 ; CHECK: select i1 %{{.*}}, i32 1, i32 0
     51 
     52 	%result = load i32, i32* %select
     53 	ret i32 %result
     54 }
     55 
     56 define i32 @test3(i32 %x) {
     57 ; CHECK-LABEL: @test3(
     58 entry:
     59 	%a = alloca [2 x i32]
     60 ; CHECK-NOT: alloca
     61 
     62   ; Note that we build redundant GEPs here to ensure that having different GEPs
     63   ; into the same alloca partation continues to work with PHI speculation. This
     64   ; was the underlying cause of PR13926.
     65   %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0
     66   %a0b = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0
     67   %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1
     68   %a1b = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1
     69 	store i32 0, i32* %a0
     70 	store i32 1, i32* %a1
     71 ; CHECK-NOT: store
     72 
     73   switch i32 %x, label %bb0 [ i32 1, label %bb1
     74                               i32 2, label %bb2
     75                               i32 3, label %bb3
     76                               i32 4, label %bb4
     77                               i32 5, label %bb5
     78                               i32 6, label %bb6
     79                               i32 7, label %bb7 ]
     80 
     81 bb0:
     82 	br label %exit
     83 bb1:
     84 	br label %exit
     85 bb2:
     86 	br label %exit
     87 bb3:
     88 	br label %exit
     89 bb4:
     90 	br label %exit
     91 bb5:
     92 	br label %exit
     93 bb6:
     94 	br label %exit
     95 bb7:
     96 	br label %exit
     97 
     98 exit:
     99 	%phi = phi i32* [ %a1, %bb0 ], [ %a0, %bb1 ], [ %a0, %bb2 ], [ %a1, %bb3 ],
    100                   [ %a1b, %bb4 ], [ %a0b, %bb5 ], [ %a0b, %bb6 ], [ %a1b, %bb7 ]
    101 ; CHECK: phi i32 [ 1, %{{.*}} ], [ 0, %{{.*}} ], [ 0, %{{.*}} ], [ 1, %{{.*}} ], [ 1, %{{.*}} ], [ 0, %{{.*}} ], [ 0, %{{.*}} ], [ 1, %{{.*}} ]
    102 
    103 	%result = load i32, i32* %phi
    104 	ret i32 %result
    105 }
    106 
    107 define i32 @test4() {
    108 ; CHECK-LABEL: @test4(
    109 entry:
    110 	%a = alloca [2 x i32]
    111 ; CHECK-NOT: alloca
    112 
    113   %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0
    114   %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1
    115 	store i32 0, i32* %a0
    116 	store i32 1, i32* %a1
    117 	%v0 = load i32, i32* %a0
    118 	%v1 = load i32, i32* %a1
    119 ; CHECK-NOT: store
    120 ; CHECK-NOT: load
    121 
    122 	%cond = icmp sle i32 %v0, %v1
    123 	%select = select i1 %cond, i32* %a0, i32* %a0
    124 ; CHECK-NOT: select
    125 
    126 	%result = load i32, i32* %select
    127 	ret i32 %result
    128 ; CHECK: ret i32 0
    129 }
    130 
    131 define i32 @test5(i32* %b) {
    132 ; CHECK-LABEL: @test5(
    133 entry:
    134 	%a = alloca [2 x i32]
    135 ; CHECK-NOT: alloca
    136 
    137   %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1
    138 	store i32 1, i32* %a1
    139 ; CHECK-NOT: store
    140 
    141 	%select = select i1 true, i32* %a1, i32* %b
    142 ; CHECK-NOT: select
    143 
    144 	%result = load i32, i32* %select
    145 ; CHECK-NOT: load
    146 
    147 	ret i32 %result
    148 ; CHECK: ret i32 1
    149 }
    150 
    151 declare void @f(i32*, i32*)
    152 
    153 define i32 @test6(i32* %b) {
    154 ; CHECK-LABEL: @test6(
    155 entry:
    156 	%a = alloca [2 x i32]
    157   %c = alloca i32
    158 ; CHECK-NOT: alloca
    159 
    160   %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1
    161 	store i32 1, i32* %a1
    162 
    163 	%select = select i1 true, i32* %a1, i32* %b
    164 	%select2 = select i1 false, i32* %a1, i32* %b
    165   %select3 = select i1 false, i32* %c, i32* %b
    166 ; CHECK: %[[select2:.*]] = select i1 false, i32* undef, i32* %b
    167 ; CHECK: %[[select3:.*]] = select i1 false, i32* undef, i32* %b
    168 
    169   ; Note, this would potentially escape the alloca pointer except for the
    170   ; constant folding of the select.
    171   call void @f(i32* %select2, i32* %select3)
    172 ; CHECK: call void @f(i32* %[[select2]], i32* %[[select3]])
    173 
    174 
    175 	%result = load i32, i32* %select
    176 ; CHECK-NOT: load
    177 
    178   %dead = load i32, i32* %c
    179 
    180 	ret i32 %result
    181 ; CHECK: ret i32 1
    182 }
    183 
    184 define i32 @test7() {
    185 ; CHECK-LABEL: @test7(
    186 ; CHECK-NOT: alloca
    187 
    188 entry:
    189   %X = alloca i32
    190   br i1 undef, label %good, label %bad
    191 
    192 good:
    193   %Y1 = getelementptr i32, i32* %X, i64 0
    194   store i32 0, i32* %Y1
    195   br label %exit
    196 
    197 bad:
    198   %Y2 = getelementptr i32, i32* %X, i64 1
    199   store i32 0, i32* %Y2
    200   br label %exit
    201 
    202 exit:
    203 	%P = phi i32* [ %Y1, %good ], [ %Y2, %bad ]
    204 ; CHECK: %[[phi:.*]] = phi i32 [ 0, %good ],
    205   %Z2 = load i32, i32* %P
    206   ret i32 %Z2
    207 ; CHECK: ret i32 %[[phi]]
    208 }
    209 
    210 define i32 @test8(i32 %b, i32* %ptr) {
    211 ; Ensure that we rewrite allocas to the used type when that use is hidden by
    212 ; a PHI that can be speculated.
    213 ; CHECK-LABEL: @test8(
    214 ; CHECK-NOT: alloca
    215 ; CHECK-NOT: load
    216 ; CHECK: %[[value:.*]] = load i32, i32* %ptr
    217 ; CHECK-NOT: load
    218 ; CHECK: %[[result:.*]] = phi i32 [ undef, %else ], [ %[[value]], %then ]
    219 ; CHECK-NEXT: ret i32 %[[result]]
    220 
    221 entry:
    222   %f = alloca float
    223   %test = icmp ne i32 %b, 0
    224   br i1 %test, label %then, label %else
    225 
    226 then:
    227   br label %exit
    228 
    229 else:
    230   %bitcast = bitcast float* %f to i32*
    231   br label %exit
    232 
    233 exit:
    234   %phi = phi i32* [ %bitcast, %else ], [ %ptr, %then ]
    235   %loaded = load i32, i32* %phi, align 4
    236   ret i32 %loaded
    237 }
    238 
    239 define i32 @test9(i32 %b, i32* %ptr) {
    240 ; Same as @test8 but for a select rather than a PHI node.
    241 ; CHECK-LABEL: @test9(
    242 ; CHECK-NOT: alloca
    243 ; CHECK-NOT: load
    244 ; CHECK: %[[value:.*]] = load i32, i32* %ptr
    245 ; CHECK-NOT: load
    246 ; CHECK: %[[result:.*]] = select i1 %{{.*}}, i32 undef, i32 %[[value]]
    247 ; CHECK-NEXT: ret i32 %[[result]]
    248 
    249 entry:
    250   %f = alloca float
    251   store i32 0, i32* %ptr
    252   %test = icmp ne i32 %b, 0
    253   %bitcast = bitcast float* %f to i32*
    254   %select = select i1 %test, i32* %bitcast, i32* %ptr
    255   %loaded = load i32, i32* %select, align 4
    256   ret i32 %loaded
    257 }
    258 
    259 define float @test10(i32 %b, float* %ptr) {
    260 ; Don't try to promote allocas which are not elligible for it even after
    261 ; rewriting due to the necessity of inserting bitcasts when speculating a PHI
    262 ; node.
    263 ; CHECK-LABEL: @test10(
    264 ; CHECK: %[[alloca:.*]] = alloca
    265 ; CHECK: %[[argvalue:.*]] = load float, float* %ptr
    266 ; CHECK: %[[cast:.*]] = bitcast double* %[[alloca]] to float*
    267 ; CHECK: %[[allocavalue:.*]] = load float, float* %[[cast]]
    268 ; CHECK: %[[result:.*]] = phi float [ %[[allocavalue]], %else ], [ %[[argvalue]], %then ]
    269 ; CHECK-NEXT: ret float %[[result]]
    270 
    271 entry:
    272   %f = alloca double
    273   store double 0.0, double* %f
    274   %test = icmp ne i32 %b, 0
    275   br i1 %test, label %then, label %else
    276 
    277 then:
    278   br label %exit
    279 
    280 else:
    281   %bitcast = bitcast double* %f to float*
    282   br label %exit
    283 
    284 exit:
    285   %phi = phi float* [ %bitcast, %else ], [ %ptr, %then ]
    286   %loaded = load float, float* %phi, align 4
    287   ret float %loaded
    288 }
    289 
    290 define float @test11(i32 %b, float* %ptr) {
    291 ; Same as @test10 but for a select rather than a PHI node.
    292 ; CHECK-LABEL: @test11(
    293 ; CHECK: %[[alloca:.*]] = alloca
    294 ; CHECK: %[[cast:.*]] = bitcast double* %[[alloca]] to float*
    295 ; CHECK: %[[allocavalue:.*]] = load float, float* %[[cast]]
    296 ; CHECK: %[[argvalue:.*]] = load float, float* %ptr
    297 ; CHECK: %[[result:.*]] = select i1 %{{.*}}, float %[[allocavalue]], float %[[argvalue]]
    298 ; CHECK-NEXT: ret float %[[result]]
    299 
    300 entry:
    301   %f = alloca double
    302   store double 0.0, double* %f
    303   store float 0.0, float* %ptr
    304   %test = icmp ne i32 %b, 0
    305   %bitcast = bitcast double* %f to float*
    306   %select = select i1 %test, float* %bitcast, float* %ptr
    307   %loaded = load float, float* %select, align 4
    308   ret float %loaded
    309 }
    310 
    311 define i32 @test12(i32 %x, i32* %p) {
    312 ; Ensure we don't crash or fail to nuke dead selects of allocas if no load is
    313 ; never found.
    314 ; CHECK-LABEL: @test12(
    315 ; CHECK-NOT: alloca
    316 ; CHECK-NOT: select
    317 ; CHECK: ret i32 %x
    318 
    319 entry:
    320   %a = alloca i32
    321   store i32 %x, i32* %a
    322   %dead = select i1 undef, i32* %a, i32* %p
    323   %load = load i32, i32* %a
    324   ret i32 %load
    325 }
    326 
    327 define i32 @test13(i32 %x, i32* %p) {
    328 ; Ensure we don't crash or fail to nuke dead phis of allocas if no load is ever
    329 ; found.
    330 ; CHECK-LABEL: @test13(
    331 ; CHECK-NOT: alloca
    332 ; CHECK-NOT: phi
    333 ; CHECK: ret i32 %x
    334 
    335 entry:
    336   %a = alloca i32
    337   store i32 %x, i32* %a
    338   br label %loop
    339 
    340 loop:
    341   %phi = phi i32* [ %p, %entry ], [ %a, %loop ]
    342   br i1 undef, label %loop, label %exit
    343 
    344 exit:
    345   %load = load i32, i32* %a
    346   ret i32 %load
    347 }
    348 
    349 define i32 @test14(i1 %b1, i1 %b2, i32* %ptr) {
    350 ; Check for problems when there are both selects and phis and one is
    351 ; speculatable toward promotion but the other is not. That should block all of
    352 ; the speculation.
    353 ; CHECK-LABEL: @test14(
    354 ; CHECK: alloca
    355 ; CHECK: alloca
    356 ; CHECK: select
    357 ; CHECK: phi
    358 ; CHECK: phi
    359 ; CHECK: select
    360 ; CHECK: ret i32
    361 
    362 entry:
    363   %f = alloca i32
    364   %g = alloca i32
    365   store i32 0, i32* %f
    366   store i32 0, i32* %g
    367   %f.select = select i1 %b1, i32* %f, i32* %ptr
    368   br i1 %b2, label %then, label %else
    369 
    370 then:
    371   br label %exit
    372 
    373 else:
    374   br label %exit
    375 
    376 exit:
    377   %f.phi = phi i32* [ %f, %then ], [ %f.select, %else ]
    378   %g.phi = phi i32* [ %g, %then ], [ %ptr, %else ]
    379   %f.loaded = load i32, i32* %f.phi
    380   %g.select = select i1 %b1, i32* %g, i32* %g.phi
    381   %g.loaded = load i32, i32* %g.select
    382   %result = add i32 %f.loaded, %g.loaded
    383   ret i32 %result
    384 }
    385 
    386 define i32 @PR13905() {
    387 ; Check a pattern where we have a chain of dead phi nodes to ensure they are
    388 ; deleted and promotion can proceed.
    389 ; CHECK-LABEL: @PR13905(
    390 ; CHECK-NOT: alloca i32
    391 ; CHECK: ret i32 undef
    392 
    393 entry:
    394   %h = alloca i32
    395   store i32 0, i32* %h
    396   br i1 undef, label %loop1, label %exit
    397 
    398 loop1:
    399   %phi1 = phi i32* [ null, %entry ], [ %h, %loop1 ], [ %h, %loop2 ]
    400   br i1 undef, label %loop1, label %loop2
    401 
    402 loop2:
    403   br i1 undef, label %loop1, label %exit
    404 
    405 exit:
    406   %phi2 = phi i32* [ %phi1, %loop2 ], [ null, %entry ]
    407   ret i32 undef
    408 }
    409 
    410 define i32 @PR13906() {
    411 ; Another pattern which can lead to crashes due to failing to clear out dead
    412 ; PHI nodes or select nodes. This triggers subtly differently from the above
    413 ; cases because the PHI node is (recursively) alive, but the select is dead.
    414 ; CHECK-LABEL: @PR13906(
    415 ; CHECK-NOT: alloca
    416 
    417 entry:
    418   %c = alloca i32
    419   store i32 0, i32* %c
    420   br label %for.cond
    421 
    422 for.cond:
    423   %d.0 = phi i32* [ undef, %entry ], [ %c, %if.then ], [ %d.0, %for.cond ]
    424   br i1 undef, label %if.then, label %for.cond
    425 
    426 if.then:
    427   %tmpcast.d.0 = select i1 undef, i32* %c, i32* %d.0
    428   br label %for.cond
    429 }
    430 
    431 define i64 @PR14132(i1 %flag) {
    432 ; CHECK-LABEL: @PR14132(
    433 ; Here we form a PHI-node by promoting the pointer alloca first, and then in
    434 ; order to promote the other two allocas, we speculate the load of the
    435 ; now-phi-node-pointer. In doing so we end up loading a 64-bit value from an i8
    436 ; alloca. While this is a bit dubious, we were asserting on trying to
    437 ; rewrite it. The trick is that the code using the value may carefully take
    438 ; steps to only use the not-undef bits, and so we need to at least loosely
    439 ; support this..
    440 entry:
    441   %a = alloca i64, align 8
    442   %b = alloca i8, align 8
    443   %ptr = alloca i64*, align 8
    444 ; CHECK-NOT: alloca
    445 
    446   %ptr.cast = bitcast i64** %ptr to i8**
    447   store i64 0, i64* %a, align 8
    448   store i8 1, i8* %b, align 8
    449   store i64* %a, i64** %ptr, align 8
    450   br i1 %flag, label %if.then, label %if.end
    451 
    452 if.then:
    453   store i8* %b, i8** %ptr.cast, align 8
    454   br label %if.end
    455 ; CHECK-NOT: store
    456 ; CHECK: %[[ext:.*]] = zext i8 1 to i64
    457 
    458 if.end:
    459   %tmp = load i64*, i64** %ptr, align 8
    460   %result = load i64, i64* %tmp, align 8
    461 ; CHECK-NOT: load
    462 ; CHECK: %[[result:.*]] = phi i64 [ %[[ext]], %if.then ], [ 0, %entry ]
    463 
    464   ret i64 %result
    465 ; CHECK-NEXT: ret i64 %[[result]]
    466 }
    467 
    468 define float @PR16687(i64 %x, i1 %flag) {
    469 ; CHECK-LABEL: @PR16687(
    470 ; Check that even when we try to speculate the same phi twice (in two slices)
    471 ; on an otherwise promotable construct, we don't get ahead of ourselves and try
    472 ; to promote one of the slices prior to speculating it.
    473 
    474 entry:
    475   %a = alloca i64, align 8
    476   store i64 %x, i64* %a
    477   br i1 %flag, label %then, label %else
    478 ; CHECK-NOT: alloca
    479 ; CHECK-NOT: store
    480 ; CHECK: %[[lo:.*]] = trunc i64 %x to i32
    481 ; CHECK: %[[shift:.*]] = lshr i64 %x, 32
    482 ; CHECK: %[[hi:.*]] = trunc i64 %[[shift]] to i32
    483 
    484 then:
    485   %a.f = bitcast i64* %a to float*
    486   br label %end
    487 ; CHECK: %[[lo_cast:.*]] = bitcast i32 %[[lo]] to float
    488 
    489 else:
    490   %a.raw = bitcast i64* %a to i8*
    491   %a.raw.4 = getelementptr i8, i8* %a.raw, i64 4
    492   %a.raw.4.f = bitcast i8* %a.raw.4 to float*
    493   br label %end
    494 ; CHECK: %[[hi_cast:.*]] = bitcast i32 %[[hi]] to float
    495 
    496 end:
    497   %a.phi.f = phi float* [ %a.f, %then ], [ %a.raw.4.f, %else ]
    498   %f = load float, float* %a.phi.f
    499   ret float %f
    500 ; CHECK: %[[phi:.*]] = phi float [ %[[lo_cast]], %then ], [ %[[hi_cast]], %else ]
    501 ; CHECK-NOT: load
    502 ; CHECK: ret float %[[phi]]
    503 }
    504 
    505 ; Verifies we fixed PR20425. We should be able to promote all alloca's to
    506 ; registers in this test.
    507 ;
    508 ; %0 = slice
    509 ; %1 = slice
    510 ; %2 = phi(%0, %1) // == slice
    511 define float @simplify_phi_nodes_that_equal_slice(i1 %cond, float* %temp) {
    512 ; CHECK-LABEL: @simplify_phi_nodes_that_equal_slice(
    513 entry:
    514   %arr = alloca [4 x float], align 4
    515 ; CHECK-NOT: alloca
    516   br i1 %cond, label %then, label %else
    517 
    518 then:
    519   %0 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3
    520   store float 1.000000e+00, float* %0, align 4
    521   br label %merge
    522 
    523 else:
    524   %1 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3
    525   store float 2.000000e+00, float* %1, align 4
    526   br label %merge
    527 
    528 merge:
    529   %2 = phi float* [ %0, %then ], [ %1, %else ]
    530   store float 0.000000e+00, float* %temp, align 4
    531   %3 = load float, float* %2, align 4
    532   ret float %3
    533 }
    534 
    535 ; A slightly complicated example for PR20425.
    536 ;
    537 ; %0 = slice
    538 ; %1 = phi(%0) // == slice
    539 ; %2 = slice
    540 ; %3 = phi(%1, %2) // == slice
    541 define float @simplify_phi_nodes_that_equal_slice_2(i1 %cond, float* %temp) {
    542 ; CHECK-LABEL: @simplify_phi_nodes_that_equal_slice_2(
    543 entry:
    544   %arr = alloca [4 x float], align 4
    545 ; CHECK-NOT: alloca
    546   br i1 %cond, label %then, label %else
    547 
    548 then:
    549   %0 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3
    550   store float 1.000000e+00, float* %0, align 4
    551   br label %then2
    552 
    553 then2:
    554   %1 = phi float* [ %0, %then ]
    555   store float 2.000000e+00, float* %1, align 4
    556   br label %merge
    557 
    558 else:
    559   %2 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3
    560   store float 3.000000e+00, float* %2, align 4
    561   br label %merge
    562 
    563 merge:
    564   %3 = phi float* [ %1, %then2 ], [ %2, %else ]
    565   store float 0.000000e+00, float* %temp, align 4
    566   %4 = load float, float* %3, align 4
    567   ret float %4
    568 }
    569 
    570 %struct.S = type { i32 }
    571 
    572 ; Verifies we fixed PR20822. We have a foldable PHI feeding a speculatable PHI
    573 ; which requires the rewriting of the speculated PHI to handle insertion
    574 ; when the incoming pointer is itself from a PHI node. We would previously
    575 ; insert a bitcast instruction *before* a PHI, producing an invalid module;
    576 ; make sure we insert *after* the first non-PHI instruction.
    577 define void @PR20822() {
    578 ; CHECK-LABEL: @PR20822(
    579 entry:
    580   %f = alloca %struct.S, align 4
    581 ; CHECK: %[[alloca:.*]] = alloca
    582   br i1 undef, label %if.end, label %for.cond
    583 
    584 for.cond:                                         ; preds = %for.cond, %entry
    585   br label %if.end
    586 
    587 if.end:                                           ; preds = %for.cond, %entry
    588   %f2 = phi %struct.S* [ %f, %entry ], [ %f, %for.cond ]
    589 ; CHECK: phi i32
    590 ; CHECK: %[[cast:.*]] = bitcast i32* %[[alloca]] to %struct.S*
    591   phi i32 [ undef, %entry ], [ undef, %for.cond ]
    592   br i1 undef, label %if.then5, label %if.then2
    593 
    594 if.then2:                                         ; preds = %if.end
    595   br label %if.then5
    596 
    597 if.then5:                                         ; preds = %if.then2, %if.end
    598   %f1 = phi %struct.S* [ undef, %if.then2 ], [ %f2, %if.end ]
    599 ; CHECK: phi {{.*}} %[[cast]]
    600   store %struct.S undef, %struct.S* %f1, align 4
    601   ret void
    602 }
    603