Instruction does not dominate all uses!

[regehr]

this input triggers a souper bug:

; ModuleID = 'foo.ll'
source_filename = "small.c"
target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

@a = external dso_local local_unnamed_addr global i32, align 4

define dso_local i32 @d() local_unnamed_addr {
cont.lr.ph.lr.ph:
  %0 = load i32, i32* @a, align 4, !tbaa !0
  %1 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %0, i32 %0)
  %2 = extractvalue { i32, i1 } %1, 0
  %3 = extractvalue { i32, i1 } %1, 1
  %4 = xor i1 %3, true
  br label %cont.lr.ph

cont.lr.ph:                                       ; preds = %cont.lr.ph.lr.ph
  br label %while.body.lr.ph

while.body.lr.ph:                                 ; preds = %cont.lr.ph
  br label %while.body

trap.loopexit:                                    ; preds = %if.end, %while.body
  ret i32 undef

cont:                                             ; preds = %if.end
  %5 = phi i32 [ %2, %if.end ]
  %e.17 = phi i32 [ undef, %if.end ]
  %tobool = icmp ne i32 %5, 0
  br i1 %tobool, label %while.body, label %cont.while.end_crit_edge, !llvm.loop !4

while.body:                                       ; preds = %cont, %while.body.lr.ph
  %e.1716 = phi i32 [ undef, %while.body.lr.ph ], [ %e.17, %cont ]
  %6 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %e.1716, i32 1), !nosanitize !6
  %7 = extractvalue { i32, i1 } %6, 1, !nosanitize !6
  %8 = xor i1 %7, true, !nosanitize !6
  br i1 %8, label %cont1, label %trap.loopexit, !nosanitize !6

cont1:                                            ; preds = %while.body
  br label %if.end

if.end:                                           ; preds = %cont1
  br i1 %4, label %cont, label %trap.loopexit, !llvm.loop !4, !nosanitize !6

cont.while.end_crit_edge:                         ; preds = %cont
  ret i32 undef
}

; Function Attrs: nofree nosync nounwind readnone speculatable willreturn
declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32) #0

attributes #0 = { nofree nosync nounwind readnone speculatable willreturn }

!0 = !{!1, !1, i64 0}
!1 = !{!"int", !2, i64 0}
!2 = !{!"omnipotent char", !3, i64 0}
!3 = !{!"Simple C/C++ TBAA"}
!4 = distinct !{!4, !5}
!5 = !{!"llvm.loop.mustprogress"}
!6 = !{}

regehr@home:~$ /home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt -load /home/regehr/souper-regehr/build/libsouperPass.so -souper-enumerative-synthesis-max-instructions=1 -S -o - -souper foo.ll
Instruction does not dominate all uses!
  %4 = add i32 %0, %0
  %tobool = icmp ne i32 %4, 0
in function d
LLVM ERROR: Broken function found, compilation aborted!
PLEASE submit a bug report to https://bugs.llvm.org/ and include the crash backtrace.
Stack dump:
0.	Program arguments: /home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt -load /home/regehr/souper-regehr/build/libsouperPass.so -souper-enumerative-synthesis-max-instructions=1 -S -o - -souper foo.ll
1.	Running pass 'Function Pass Manager' on module 'foo.ll'.
2.	Running pass 'Module Verifier' on function '@d'
 #0 0x0000000002801963 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x2801963)
 #1 0x00000000027ff69e llvm::sys::RunSignalHandlers() (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x27ff69e)
 #2 0x0000000002801e2a SignalHandler(int) (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x2801e2a)
 #3 0x00007fdb878a71f0 __restore_rt (/lib/x86_64-linux-gnu/libpthread.so.0+0x141f0)
 #4 0x00007fdb87306fbb raise ./signal/../sysdeps/unix/sysv/linux/raise.c:50:1
 #5 0x00007fdb872ec864 abort ./stdlib/abort.c:81:7
 #6 0x0000000002784ee9 (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x2784ee9)
 #7 0x0000000002784d06 (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x2784d06)
 #8 0x00000000020b7d2f (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x20b7d2f)
 #9 0x000000000202f938 llvm::FPPassManager::runOnFunction(llvm::Function&) (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x202f938)
#10 0x00000000020361b1 llvm::FPPassManager::runOnModule(llvm::Module&) (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x20361b1)
#11 0x000000000202ffec llvm::legacy::PassManagerImpl::run(llvm::Module&) (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x202ffec)
#12 0x000000000073659a main (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x73659a)
#13 0x00007fdb872ee565 __libc_start_main ./csu/../csu/libc-start.c:332:16
#14 0x000000000071fd7e _start (/home/regehr/souper-regehr/third_party/llvm-Release-install/bin/opt+0x71fd7e)
Aborted (core dumped)
regehr@home:~$