<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/79742>79742</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            llvm crash on loop-vectorize: Assertion `OldResSizeInBits > NewResSizeInBits && "Nothing to shrink?"' failed.
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            new issue
      </td>
    </tr>

    <tr>
      <th>Assignees</th>
      <td>
      </td>
    </tr>

    <tr>
      <th>Reporter</th>
      <td>
          shao-hua-li
      </td>
    </tr>
</table>

<pre>
    llvm crashes on the following IR.

Bisected to 822c749aec69ace75bd3923a4c850e2fd2e34fb1, which was committed by @fhahn 

Compiler explorer: https://godbolt.org/z/rWj9dhvPo

```llvm
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"

define void @i(i64 %0) {
entry:
  %conv = sext i16 1 to i32
  br label %for.body

for.body:                                         ; preds = %for.body, %entry
  %1 = phi i32 [ 0, %entry ], [ %inc, %for.body ]
 %tobool.not.i = icmp eq i64 %0, 0
  %..i = select i1 %tobool.not.i, i32 0, i32 0
  %cmp = icmp eq i32 %..i, 0
  %conv1 = zext i1 %tobool.not.i to i32
  %or = or i32 %conv1, %conv
  %cmp2 = icmp slt i32 %or, 7
 %conv4 = zext i1 %cmp2 to i64
  store i64 %conv4, ptr null, align 8
 %inc = add i32 %1, 1
  %tobool.not = icmp eq i32 %inc, 0
  br i1 %tobool.not, label %for.cond.for.end_crit_edge, label %for.body

for.cond.for.end_crit_edge:                       ; preds = %for.body
  ret void
}
```

```console
% opt -passes=loop-vectorize reduced.ll
PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
Stack dump:
0.      Program arguments: /zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/opt -disable-output -passes=loop-vectorize reduced.ll
 #0 0x00007f5302fedeff llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x902eff)
 #1 0x00007f5302feb654 SignalHandler(int) Signals.cpp:0:0
 #2 0x00007f5302300090 (/lib/x86_64-linux-gnu/libc.so.6+0x43090)
 #3 0x00007f5304a458f0 llvm::InnerLoopVectorizer::truncateToMinimalBitwidths(llvm::VPTransformState&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x235a8f0)
 #4 0x00007f5304a49d95 llvm::InnerLoopVectorizer::fixVectorizedLoop(llvm::VPTransformState&, llvm::VPlan&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x235ed95)
 #5 0x00007f5304a4abb1 llvm::LoopVectorizationPlanner::executePlan(llvm::ElementCount, unsigned int, llvm::VPlan&, llvm::InnerLoopVectorizer&, llvm::DominatorTree*, bool, llvm::DenseMap<llvm::SCEV const*, llvm::Value*, llvm::DenseMapInfo<llvm::SCEV const*, void>, llvm::detail::DenseMapPair<llvm::SCEV const*, llvm::Value*>>*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x235fbb1)
 #6 0x00007f5304a4d564 llvm::LoopVectorizePass::processLoop(llvm::Loop*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x2362564)
 #7 0x00007f5304a4fbdd llvm::LoopVectorizePass::runImpl(llvm::Function&, llvm::ScalarEvolution&, llvm::LoopInfo&, llvm::TargetTransformInfo&, llvm::DominatorTree&, llvm::BlockFrequencyInfo*, llvm::TargetLibraryInfo*, llvm::DemandedBits&, llvm::AssumptionCache&, llvm::LoopAccessInfoManager&, llvm::OptimizationRemarkEmitter&, llvm::ProfileSummaryInfo*) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x2364bdd)
 #8 0x00007f5304a50e20 llvm::LoopVectorizePass::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x2365e20)
 #9 0x00007f5305e0d916 llvm::detail::PassModel<llvm::Function, llvm::LoopVectorizePass, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x3722916)
#10 0x00007f53031fd3fd llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0xb123fd)
#11 0x00007f5305e069f6 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x371b9f6)
#12 0x00007f53031fbc8d llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0xb10c8d)
#13 0x00007f5305e0d696 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::PreservedAnalyses, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0x3722696)
#14 0x00007f53031f9c0d llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/../lib/libLLVM-18git.so+0xb0ec0d)
#15 0x0000555c5281fcb5 llvm::runPassPipeline(llvm::StringRef, llvm::Module&, llvm::TargetMachine*, llvm::TargetLibraryInfoImpl*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::ToolOutputFile*, llvm::StringRef, llvm::ArrayRef<llvm::PassPlugin>, llvm::opt_tool::OutputKind, llvm::opt_tool::VerifierKind, bool, bool, bool, bool, bool, bool, bool) (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/opt+0x25cb5)
#16 0x0000555c52813876 main (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/opt+0x19876)
#17 0x00007f53022e1083 __libc_start_main /build/glibc-wuryBv/glibc-2.31/csu/../csu/libc-start.c:342:3
#18 0x0000555c5281451e _start (/zdata/shaoli/compilers/ccbuilder-compilers/clang-822c749aec69ace75bd3923a4c850e2fd2e34fb1/bin/opt+0x1a51e)
[1] 1975861 segmentation fault   -disable-output -passes=loop-vectorize reduced.ll
```


This IR is reduced from 
```C
long a, b;
int c, d, f;
static long *e = &b;
static short g = 5;
int h() {
  if (a)
    return 0;
  return 5;
}
void i() {
  int j;
  long **k = &e;
  for (; d; d++) {
    j = h();
    *e = 6 >= (g | (j + c == 0));
  }
  j =  &k || 1;
  short *l[6];
  l[f] = &g;
}
int main() {}
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzsWktz27iy_jXwBiUVCT4kLryQbKtu6sYzrtiVu3SBQJNCDAIcAPQjv_4WQD1IWp44c-bMuM6ZlEKTQHej--uXQIhaK2oFcI6yNcouz2jnttqc2y3Vs21HZ1KclZq_nEv52GBmqN2CxVphtwVcaSn1k1A1_vRljqJLFK3661pYYA44dhovCWGLtKDA8oIyWGQlTwqS0JQtswhIxQkkaVXGiFzgp61gW_xELWa6aYTzIsoXjNKo2tKtwsM1LnTTCgkGw3MrtQGDkhXeOtdalKwQ2SCyqTUvtXRzbWpENt8R2Zj_-1bw7eONHkpCedR_vI39kKOmBoc5dVTSF905jJJLjAiBWYOSFcxasohQskpIuPjHePzo7_I0XGZif1MtPVNMljO19Df5nidPZ7cxWSJCRus7I1oJ-7Wfl_l9ns469aD0k5pJobrnWa26A1d_5VAJBfhRC-6RE4gsRZ5iRLIIkQKjxbqnA-XMi8cqPGFPwLR6DKtZeHZYxDmOvQtFQvZEpcGSliA9daXN3MfGcPHDWLLC7_2HkjVuDXC7M_QomFz4x17Ro5ZxoGu3wiuGUbbG0ZASo-wyPGdrPyYU283uxQaCXhwimdOl1nKutJuLIFiwpsXwGz6CdoGjwfLzHZ0FCcyjNJXiGbxm0fFmAHHTjlfxJgSh03W8M3pTv_feeKXt2DWIZNoEem32YoOMnfn-fqwIOWpipdvzaOMZFkeEPGM6VSSwewXydC_UOm1gD1tg8oJaZ7DqpPT3VIpa4eVRtFAsCKac75cP6sYDRY8mnwJu595oEKBTpPz8KGiZVnzub0Dxe2aEuwdewyuyU7H9Buub0f52bO_0NeBCqu4WWlxOatLJQsW0slrCbpRkWLcOz1pqLViUXEqt29kjMKeN-A7YAO8Y8LmUPcPN56vV7RW2XdkIhykuuxobaLVx3qGTEirctivnTDeIbEJ97P_MWqO_AXOIbIS1HVhENpgqjoVisuMQ-kNoF7ik7MEZymDXIm4dZQ-Yd017KD7RHEXFjdG1oQ2mpu4aUM4rgX3d9lUYkY1vSVIgsmG7yu_XZKzshORgZqNRSVU9e3_n2ZRCIbIJKHJhaSlhpjvXdj-BKkYkiXD0HEVRtKiyJCIVcKgqHFBLVihZ2Rfb39wYoVzA4c4Dg8jySGTo0722zgBtEMlDCVEuFG7fH_5CNOZz72tR9tfPn79ez-JlLdzcakTW0XMREagqRIqj_fHE_jLPUnwrakXl_1DFJRjfjHpz-mE7Z62Pgyj8PwgiI0FJFEVFtAOg12jXCwc90E-wudXzPGiXJlERjZRLhjJTmmbLKho455NSYD5r3X7du9j0E850ilEHd_paKNFQuRbuSXC3tSO_fb25M1TZSpvm1lEHwXkfz2skyeiyGiOTTpApeJG9B5lKPB-GuCf4MSAXeEggqfq4MAEvshFM2QQmWpbxwJwhQtQJrbx5ao8VPAPrHPQmD1C6kuCL3YXuVGhUnQrfx3mf9afhuviBc6Y0l7oRijpt7gwAIis_65vjhAqUhWvaouTiOHh7cfUV-3bjdnwDfajs4NXoXsonVenflxS6XnI1ZufgqJBjUTdUmJ9WKrkKslcfNLiq0tMPgiufBBfP8vSN4IIbaneNpDWagbWvcq8f-KDG5yTL05Hxi4nxVcn5j403nfrUtHJk-KZTzOfeqxy4ZVRSc_WoZXdy3q8RYnY6cRe2YodSdpJmkmCT2bXU7GFj4LcOFHvpBaxOLfJZlIaa0xSX0FDFga-Fs69WWFnbNa2364Ky7WsNvHEr5iPFy76mitYnysSvrRPNrnZ9gYaah6uwB39NeWN0JSTcdk0z1PdDBltacj4KtuU42Lzg6F3B9r5AWykqX6ywe5SHhevA5EvTB-17eQZk_PWgGAKWQcSLOH-jZHu8rjUHedrsV0E5BnoSY2DBPALvAQX7x2D2n_8i_yULQoo4P_jPfykf7UqSuOJJNayuwWe_Z-w_uP8Y9zImScVHsMeTtMmL6s9Im3-bu_7Jvj8h--KyqMbZRybZV7LlMPuuNe8k3Om9cd69K05bp81p6HqGnwJux_JhYSvjiC3HyZNMe05e_Fzy7GG6eCfWf1b0H7F-K_b_Ax3ou05ejOM-ncR9waL3dJ1TfvsH72nCRMCiccLsX05kWcYysowrVg7f4ZguRPuNaEEKNX7jeOuMUPUXqE5lyxv7oWvKtkHOjzYy_Q5tSqW1_DW8X90IeULIvzT9hjkrY-iLHx06OmAiu1qoVx1Qt-7eab0rMv16_ysU_z2qr2BEJcDs6fYvWX7u718fb7p1_bf_jJXZKKzySVgly0WOGyrU36ZjXCwX40ozentACMTRMsH391KU7N46atz9TuFNUAeRTe3nZk-deVk_Hh7JPPGrMdvtM7C_DZNBzpyhZJWk4ZD3uPxyAlGaxYD7hf8-kGgWwxGkbB2j7BLHxSJb5jG2UDegXNjo44p20mH8xw8-Th9VhevdVlj86QsWds-FK6MbPGG86J-lVjWmIQ9QsjukFsrhcMAX8qk6jFuvPcOBBZHV_ow8L6cUdquNw3WYz0Zit8E5gwNxjEXlPUaPu18cDug6o3B04D0MHcUdju3Cobs4IVg5_G0gYa83IquHveowmK-0CbGTrDHvL2QdPiOpGH8LzDtLBvz4CEqOQ2f0SyxrjBYX_uYbRmSNw9mrnwr7_ZGAg0X7NbyGD57dS4gHlD3AiKwkytY5yi6HZqJsXfnI25lYv0bMI-PTc4DZqzPQM36e8CIp6Bmcx4soT5N0mSVn23MSccYyliZFkRc8XrJoURaM8qJYRFAV_Eyck4ikUUyWUZFGGZn77fEiT6oYFkkCyQKlETRUyLkv6XNt6rNwnHm-KBYpOQvHwTb8NIYQBU84TCJCUHZ5ZsJvYmZlV1uURlJYZ49SnHASBj-awVrhcR6hZIVX1oIJWYjy6FfJv4C9Fd_hk1oLZ73f8C_wNBn0_TjHiJBftNsKVWOnsd0aoR5QsvGqkQWuqJDA52edked__Dw3YPD_AQAA___ZesYV">