<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/66624>66624</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            Inline assembly causing crashes in llc and Clang
        </td>
    </tr>

    <tr>
      <th>Labels</th>
      <td>
            clang
      </td>
    </tr>

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

    <tr>
      <th>Reporter</th>
      <td>
          boomanaiden154
      </td>
    </tr>
</table>

<pre>
    I'm seeing some weird behavior with inline assembly from some bitcode taken from the Linux kernel. For example, the following minified test case is taken directly a tip-of-tree kernel ([this file](https://github.com/torvalds/linux/blob/9cf26c8968b358bb14cc078f8153300a493613d4/drivers/gpu/drm/nouveau/dispnv50/ovly507e.c)) and compiled with a tip of tree `clang`:

```llvm
; ModuleID = 'bugpoint-reduced-simplified.bc'
source_filename = "drivers/gpu/drm/nouveau/dispnv50/ovly507e.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"

module asm ".weak __kcfi_typeid_base507c_ntfy_reset"
module asm ".set __kcfi_typeid_base507c_ntfy_reset, 505546111"
module asm ".weak __kcfi_typeid_base507c_ntfy_set"
module asm ".set __kcfi_typeid_base507c_ntfy_set, 924527716"
module asm ".weak __kcfi_typeid_base507c_ntfy_clr"
module asm ".set __kcfi_typeid_base507c_ntfy_clr, 2186127539"
module asm ".weak __kcfi_typeid_base507c_ntfy_wait_begun"
module asm ".set __kcfi_typeid_base507c_ntfy_wait_begun, 3421798255"
module asm ".weak __kcfi_typeid_base507c_image_clr"
module asm ".set __kcfi_typeid_base507c_image_clr, 2186127539"
module asm ".weak __kcfi_typeid_base507c_update"
module asm ".set __kcfi_typeid_base507c_update, 575022393"

@.src = external dso_local unnamed_addr constant [44 x i8], align 1

define dso_local void @ovly507e_image_set() #0 align 64 !kcfi_type !7 {
entry:
  br i1 poison, label %if.then, label %if.end

if.then: ; preds = %entry
  ret void

if.end: ; preds = %entry
  call void asm sideeffect "1:\09.byte 0x0f, 0x0b\0A.pushsection __bug_table,\22aw\22\0A2:\09.long 1b - .\09# bug_entry::bug_addr\0A\09.long ${0:c} - .\09# bug_entry::file\0A\09.word ${1:c}\09# bug_entry::line\0A\09.word ${2:c}\09# bug_entry::flags\0A\09.org 2b+${3:c}\0A.popsection\0A998:\0A\09.pushsection .discard.reachable\0A\09.long 998b - .\0A\09.popsection\0A\09", "i,i,i,i,~{dirflag},~{fpsr},~{flags}"(ptr @.src, i32 71, i32 poison, i64 12) #5
  unreachable
}

attributes #0 = { "zero-call-used-regs"="used-gpr" }
!7 = !{i32 924527716}
```

`llc` crashes with the following error message:
```shell
error: invalid operand for inline asm constraint 'i'
```

`clang` crashes with the same error message at `-O0`, but doesn't at higher optimization levels, presumably because the branch on poison gets optimized away so there's no inline asm causing issues anymore.

`clang` on the original non-minified example ends up hitting the following assertion however:
```shelll
clang: /llvm-project/clang/lib/Basic/SourceManager.cpp:868: clang::FileID clang::SourceManager::getFileIDLoaded(clang::SourceLocation::UIntTy) const: Assertion `0 && "Invalid SLocOffset or bad function choice"' failed.
```

I haven't investigated throughly, but I don't think this is a case of incorrect code as I'm seeing this in quite a few places in the Linux kernel.

Also noting here that I'm gathering the bitcode by embedding it using `-Xclang -fembed-bitcode=all` to collect bitcode directly after the frontend.

I need to do some more investigation but figured I would post something here.

CC: @nickdesaulniers as this touches the kernel + inline asm.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJykWF1v4zrO_jXqDZHAlr8vetGkCFBgDs7FvC-wd4Es0ba2suSV5KQ5F_vbF5KdNO3szCx6gBnXkvU8IimSIsOck71GfCTFjhTPD2z2g7GPrTEj00wK1GmRP7RGXB5fCK1GcIhS9-DMiHBGaQW0OLCTNBbO0g8gtZIagTmHY6su0FkzLqtb6bkRCJ69ol7m_YDwTer5DV7RalRbOBgL-MbGSSGh-7igM0qZc9h0lFp2EgV4dB44cwjSrXxCWuReXYCBl9PGdBtvEVdeILQmxc4P0kEnFZLimdB68H5yJHsi9EDooZd-mNstNyOhB2_siSnhCD2oIB-hh1aZltBDwzta8rop6zYr6rZNc86Tqu7qtMiyJGF5k5VpJnJCD8LKE9rA0U9zHAdqbeYTsjiWbtKnIiH0YE7qUiQVbjmhDaENMC2Am3GSCsVi2KgXmA6iXqRMuGK6J2USNEieSXJ9lsnyT6nTuE5lO_jDiFnhyzOQ7BkIrdq5n4zUfmNRzBzFxslxUtG825YTWi1QZ2bL8RiMptmIK5p-UTW6kHpme_QgmGeKXczsr7S4GUn2hJuJVkGtjMZHGKYfh-GtzONjI68vXR1AKa03ug4v5RVT5pvvKa0_7--tnNRNpbe6PJb5Ztav2pz1Jh77ptfzDbU8x2hHYG4MoO0Z2Sscj6-8k0d_mVCKY8scFknFj9p3l6NFh_7G8Qnt0P8v4D0USVHkZZqmP2P6rRx_Q4pVhobmBa2qtPyyDFzZr8oQoXugaV2mtCqy5stCnJn0xxb7WX9VlnuGPWQ5TaumpkXxFZHkyHr8omHusH_XMvMkmMcvyHAF7qGoioTSrMk-BQzJk62zPIYZvnm0mikQzhyV4UzBrENeEUcmhAVutPNMeyDFLs_hDWQdU_UemJK9hvSeWGAXbpp3qpORAkieXDPOaqDovnVIqoRmycpU5kBoelMpDCog1W6hRu3t5ZZXAVoLMoXJSGfimSvWxkulkN3WD_jDHGpxL-l1VfYEIRVPFoVb006xbLXuY9FHLT6BA91vsZyp1QTh2JwUiF2H3IcTDNmTFPuk2bYXj5C8JV0QOXlL2jD9tJ1mNzjkXhoNx2M790fP2ngFk2JPKTvHP3EtvXEpo3tIW9jANk4QmkGA3qyXPYVhONmIvEMRmpNqF9I1J9XzrxiW6_qGPhsrVnS6on-GDHXIf0fS3yA7xXp3BzW2B9oSulvg2R38aTuZabVcHDdNvRpoBd-bdiuk48yKrUXGh2jhT4Zpmvpm0CvBxw1WoWk4QEKpJHR____fpNoJaYMKQcRlopucvRtF9cKQElpP3sIao4FSZhSq9Pr27vKyzCGlaxQVV6eb9bsmi89Wz_fOy7y3sp09uiX4ouNWuyD4X2jNJjjtZnYoNhZ7FwTKglhxpp9CUoR3xhii0fNTUu2CeO9X0m3Rtfr5VBIpxUmZALfMDeiWiupjcYnWGgsjOsd6fK-prnxuQKXW7BBWhoCU-sSUFGAmtKFg64x9r3_HJZtZJkM-o5W81VQ_k_Fa0P0opQul1wcBgflQA27-jDx0D-3sQRh0mtDKh6-D7Ae0YCYvR_kXi_6n8ITKheWTRTePLFToLXI2O4wbtZZpPoDR68lDj95dOVAAO7MLOBPWWiS0cqDNB5XZ7IIxpXMzOmD6MhqL258panTc1VjZy3AtaKM3tyJ_bQMAtXAwTzBI7wP3x2MLjYaNyg3mjCe0Pzm69eyWrUMypYdQIG8ma_6J3BN6WD6Fgj_U-TvmJCf08D0WwH8wzXq0Wz5NJHuqyxDjcOUi2dNBxtr6buYDbpnq0S_rvhkmUBBa_7D-m-HxpJa5_3_R_v8uIeaiK4U9n27qkjJJgNCS0DKE08vqi9-_Gf5n14Ur21homYBu1kv24YORPF7ytIKOhdZi-wuPfIGBnXDxJ6lP6LzsmQ_d12DN3A_qcvW7FxBmWecHqV8h9lnSAVt6NNOB1NzY0KBBbAGZgw_d5ALQ8K9ZegQGHZ5hUoxjnP2hS7yX8kk5A9pEzwhOCX5gfmXvWfDTq89c-8_2Aji2KER0VA-Lx4Zg-kc8D9h08ftmBZDsmSkV3NUb4EapoMaV7L3t7DzaxTet0R612H40psZgOgPCLO1wCIw7u4YDCrbsZD9bFPACZzMrAZNxPgKCaRcVPxDv99Gb80RL_irQsVlpidYFG0ezejPzkEyCaLdueHcXtNsH8ZiJJmvYAz6mZVMkWZrV5cPwSEXRlCzPmqZNm6bFtmxoVSJvS97xtqsf5CNNaJY0aZ0mSZaUW44dTWlTdSUXmGYlyRMcmVTbEGvhHn2ImeGxLEuaP8SSycWfHihdw4-S4vnBPsbYbOfekTxR0nn3zuClV_j48ul3hmvmueZOqUEpHvvofWB-mK16_EXHH7vlH3LCkscIPUSB_xMAAP__RCpddA">