<table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Issue</th>
<td>
<a href=http://email.email.llvm.org/c/eJztWdtu2zgQ_Rr5hbBAkdTtwQ-13SwKFOhuu-8Gb7LV6uKKlOv263dIy4qcZNOkLbrdJoJgiZzhmTPkzISMRKs-L4IES26R5EaHEgWExnmWQGeA1wF-EcRLL7FHG8TrgGQ7a_cmoC8CcgX3trS7XoSyraFRVYfzY77v2vdaWmgWZaUNPNMcpyRP4G0EJPlgBKz5W57axna9tChIl6c2QqbcNlohEdCxS-54h-Sko28GLWCH8rsEJ1E0EQ2CD64_HfuDdI302Dq0pUJF24Lz7tWxPouqttlCN3d9JHMtVARkhfwbSHLnA-q07bsGFWD9JcoJoTQlmCZZzNI0znCK5mgLsiuv8QLG0SWMW59MlI1FNS8bwB_wztzBaoadNTylhFAJMCTToRrnF8GlQwHoa1C-qRmQyEERB-VDIH6JIm_tAuA0A1NTI8dx_camrHiznRckJ3HCE8ZlFMkizqXmWZrJTEWC5zFNlWBFTKhjAUvefHAezt8QAIB4bFDTWqSrsi4bbjWCXscBZKK3aDTiwq3ttvOIhjjEk-HhwGbyO3_kdYHwvV6h-Ts0b6H3SukD_Bqr2v6ceNeTR1dKW15WxoULtExf17z7DI23WvUSopUbo2tRQdfKwYxyaO_d45L06eamPvX4WKJ-Rb9yBc4Fhv2AATIPZVFujOWdhQQfstXrkViIELu6cFbd92b3EZ4g6vjxEkHpYiMLvmmLwmiLomQU1-3hy6cKXnRAlrEPuLgr9z4YV86MnmBZbWzlTbA4ItcK_-5PWdenLDgSjEec99oRe71cRhty06do6hOwG-z5xNMX_LzSGeVykBEfB5fYHS5Np-fYdqdJYz4Fb8nfN9dc45tc6dQsb9SANCd3AAErLsygcbsoJech8njX7KVXF9cYc7ms9-dFl8e7-N9Dn03pS15VDsml_GRm46kOTNZpOXxU3I6PfTslc18EZqMUivXHs8Gib-RGN-oiBkJTfnFOnIryCk3U5pNcuVESfaruT0nqK4BP8RvZ-kPK0-16-MQKz29YQr4W6P_7oP22v6mHhwTvm97ue_uYkD01PTF00J0p2wZFzGfTozfAISigh3o3hsDfvNtq67LlmCWbhM3B46b91MyrsumP823TD3q7TnOF6lbpymnvW1MOUfGqgWypKq3WZedEwOuL4pa7_Xdb72FT3m0klzvtOh61BjBAnCPmqu0b5TZbqlRuj_bHaoXKk2VuYd4Gy73p3LyUws2YlPA7-LWXE5fIVRSFUYi_DTphjwB_pytYHChpPxR1NZKt-8qWzl-AC92GGcoZQN2jRcmgRskNivdh_Tp_Zn5mLtLvyEWViiTJBeUUUxbLQipBCqUJL5KCZZwzkbOMxeq_zUWtGKaaSUF0LHOZRIoUQjAmuMZUxgmmJMeiiJ5z8SnnoqvF7kbL0gA_N2VecGoCXds6oiKOmWaRJiqKRZolaU5oJGiOdcxoFFONIcZ0oYcpaeu6tG60-OxXgOHXWmjYOr599cOryEOpPcFt7PP5-fn8_Hx-_mnF9M9OH8q2N0j6-udSPIsYg40wYzJisY5UjnmEZcqgKkXwzlghiqyQ4s7K9tDBT7Cy_YY16lc7oM_Ugqqc5nzGe7tru8VfPe96Meu7avHoLzilMb3_hBNTSvBst8CSCoUJxWlCRZEqXOiUcaESHkmZkmRWcaErswjiZRCvZ99vslwQTAiO4E5JRlmYJ2Apx7iIWSSKREA0apimKnQ4IZxLZt3CQ4p-a0BYlcaaayHkifvwo88MbWkrvVi7_fsK9u_o5fDRwZ023uptp40_eHDrs_X8Pwh0MOFwGIHYmHnOC0_4H0VdQ_4>53320</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>
Dead Code Elimination Regression at -O2 (trunk vs. 13.0.0)
</td>
</tr>
<tr>
<th>Labels</th>
<td>
</td>
</tr>
<tr>
<th>Assignees</th>
<td>
</td>
</tr>
<tr>
<th>Reporter</th>
<td>
Quarub
</td>
</tr>
</table>
<pre>
`cat case.c #5986`
[case.txt](https://github.com/llvm/llvm-project/files/7907296/case.txt)
```c
struct {
signed b;
char c;
unsigned : 9;
unsigned d : 1;
signed k: 7;
} e;
void foo(void);
long(a)(long f, long g) { return f > 9223372036854775807 - g ? f : g; }
int main() {
a(0, 0);
if (e.d)
e.b = 0;
if (!a(2, e.c ^ 128))
foo();
}
```
`clang-f29256a64ac11cf59cea878c8d1ba9537db4f523 (trunk) -O2` can not eliminate `foo` but `clang-llvmorg-13.0.0 -O2` can.
------------------------------------------------
`clang-f29256a64ac11cf59cea878c8d1ba9537db4f523 (trunk) -O2 -S -o /dev/stdout case.c`
<details ><summary>Reduced assembly</summary><p>
```asm
main: # @main
.cfi_startproc
# %bb.0:
pushq %rax
.cfi_def_cfa_offset 16
movzwl e+5(%rip), %eax
testl $512, %eax # imm = 0x200
je .LBB1_2
# %bb.1:
movl $0, e(%rip)
.LBB1_2:
movsbq e+4(%rip), %rax
xorq $128, %rax
jne .LBB1_5
# %bb.3:
andq $-2, %rax
movabsq $9223372036854775806, %rcx # imm = 0x7FFFFFFFFFFFFFFE
cmpq %rcx, %rax
je .LBB1_5
# %bb.4:
callq foo
.LBB1_5:
xorl %eax, %eax
popq %rcx
.cfi_def_cfa_offset 8
retq
.Lfunc_end1:
.size main, .Lfunc_end1-main
```
</p></details>
------------------------------------------------
`clang-llvmorg-13.0.0 -O2 -S -o /dev/stdout case.c`
<details ><summary>Reduced assembly</summary><p>
```asm
main: # @main
.cfi_startproc
# %bb.0:
movzwl e+5(%rip), %eax
testl $512, %eax # imm = 0x200
je .LBB1_2
# %bb.1:
movl $0, e(%rip)
.LBB1_2:
xorl %eax, %eax
retq
.Lfunc_end1:
.size main, .Lfunc_end1-main
```
</p></details>
------------------------------------------------
`clang-f29256a64ac11cf59cea878c8d1ba9537db4f523 (trunk) -v`
<details ><summary>Output</summary><p>
```
clang version 14.0.0 (https://github.com/llvm/llvm-project.git f29256a64ac11cf59cea878c8d1ba9537db4f523)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /zdata/compiler_cache/clang-f29256a64ac11cf59cea878c8d1ba9537db4f523/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0
Found candidate GCC installation: /usr/lib64/gcc/x86_64-pc-linux-gnu/11.1.0
Selected GCC installation: /usr/lib64/gcc/x86_64-pc-linux-gnu/11.1.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
```
</p></details>
------------------------------------------------
`clang-llvmorg-13.0.0 -v`
<details ><summary>Output</summary><p>
```
clang version 13.0.0 (https://github.com/llvm/llvm-project.git d7b669b3a30345cfcdb2fde2af6f48aa4b94845d)
Target: x86_64-unknown-linux-gnu
Thread model: posix
InstalledDir: /zdata/compiler_cache/clang-ed403e4cb2e5c9c61d2fbb44bae03c5603290bf1/bin
Found candidate GCC installation: /usr/lib/gcc/x86_64-pc-linux-gnu/11.1.0
Found candidate GCC installation: /usr/lib64/gcc/x86_64-pc-linux-gnu/11.1.0
Selected GCC installation: /usr/lib64/gcc/x86_64-pc-linux-gnu/11.1.0
Candidate multilib: .;@m64
Candidate multilib: 32;@m32
Selected multilib: .;@m64
```
</p></details>
------------------------------------------------
### Bisection
Bisected to: b554e41e2d15b78679231b390e543153e05c9efe
Committed by: @LebedevRI
------------------------------------------------
`clang-b554e41e2d15b78679231b390e543153e05c9efe -O2 -S -o /dev/stdout case.c`
<details ><summary>Reduced assembly</summary><p>
```asm
main: # @main
.cfi_startproc
# %bb.0:
pushq %rax
.cfi_def_cfa_offset 16
movzwl e+5(%rip), %eax
testl $512, %eax # imm = 0x200
je .LBB1_2
# %bb.1:
movl $0, e(%rip)
.LBB1_2:
movsbq e+4(%rip), %rax
xorq $128, %rax
jne .LBB1_5
# %bb.3:
andq $-2, %rax
movabsq $9223372036854775806, %rcx # imm = 0x7FFFFFFFFFFFFFFE
cmpq %rcx, %rax
je .LBB1_5
# %bb.4:
callq foo
.LBB1_5:
xorl %eax, %eax
popq %rcx
.cfi_def_cfa_offset 8
retq
.Lfunc_end1:
.size main, .Lfunc_end1-main
```
</p></details>
------------------------------------------------
Previous commit: 81441cf44c145e1d90a10c743e0190a44fbf8fcb
`clang-81441cf44c145e1d90a10c743e0190a44fbf8fcb -O2 -S -o /dev/stdout case.c`
<details ><summary>Reduced assembly</summary><p>
```asm
main: # @main
.cfi_startproc
# %bb.0:
movzwl e+5(%rip), %eax
testl $512, %eax # imm = 0x200
je .LBB1_2
# %bb.1:
movl $0, e(%rip)
.LBB1_2:
xorl %eax, %eax
retq
.Lfunc_end1:
.size main, .Lfunc_end1-main
```
</p></details>
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJztWVmP2zgM_jXOixBD1uHjIQ9N0lkUKNDddt8DXU7c-kgtOU3765dyHI8zMzudaYtutzOGYVsiRX6kSIaOZaM_L4IYK-GQEtaECgWE8iyNYTLA6wC_CPiyp7ijC_g6IOnOub0N6IuAXMG5Ldyuk6FqKhiU5eF8m-_b5r1RDoZ5URoL9yTDCclieBoFkmxQAtr6U53G1rWdcihIlqcxQrbY1kYjGdBxSu1Ei9RkoqsHLkCHsrsIJ1I0IQ2ED34-GeeDZI3MODo0hUZ504Dx_tGjPpPKpt7CtPBzJPUjlAdkhfonoGTeBtQa17U1ykH7S5QRQmlCMI1TzpKEpzhBc7QF2lXP8QLW0SWsW59UFLVDlShqkD_IO2MHrSn22vAUEkIFiCGpCfXoXwSHCSVIXwPzTc6ARF4U8aL6EOAvUdRruxBw8sBU1Yhx3L9xqEpRb-c5yQiPRcyEiiKV80wZkSapSnUkRcZpoiXLOaEeBWx5_cFbOH9DQADEY43qxiFTFlVRC2cQzHoMQJOdQ6MSH25Nu51HNMQhniwPBzST6_yRx4WE77UKzd-heQOzV9oc4Gqdbrpz4l07j660caIorQ8XGNmuqkT7GQZvje4URKuw1lSyhKmVFzPSYbz3t0vQp1PY6jTTxxLtd_QrR-BNYLhfMIjMQpUXG-tE6yDBh2zt-QiXMsS-LpxZ953dfYQ7kFpxvJSgTb5Rudg0eW6NQ1E8kqvm8OVTCQ8mIEveBxxvi30fjCuvxkxkOWNd2atgPCLXDP9uT1FVpyw4EoxHOe-NB_Z6uYw25KZN0dQmQDfo6xPPXODrmc5SLhdZ-XEwid1h0tQ9x6Y9OY31KXiL_r6-xspvYqVTtaLWg6Q5uUMQoBLSDhy3i1J8XqKOd3kvubo4xpjLVLU_b7o63oX_HvhsCl-JsvSSfMpPPMunPOCs03b0UXE7PvbNFMx9EZiOVCjWH88K865WG1PrixgIbfHFG3Eqyis0YZtPcuVGSexTdX9K0r4C9Cl-I1t_SHm6XQ-fWOH5DUvI1wL9fx-03_abenhI8L7p3L5zjwnZ07AHhg6mtUVTo4j12fToBjgEBvRQ68YQ-Fu0W-N8thzTeBOzOVhcN5_qeVnU3XG-rbuBb9caoVHVaFN67n1jiyEqXtWQLWVp9LpoPQlwfdHCCd9_N9UemvJ2o4TaGT_xqD2ABfIcMVdNV2vfbOlC-x7tj9UKFSfNwoHfBs2dbb1fCuk9phRcB7v2amISuYqiMArxt4mO2SOEvzMlbA6UtB8qdTWCrbrSFd5eEBf6hhnKGYi6h4uSgY2SGxDvk_Xr_Mz8zFyk35GLOpFxnEkqKKaMq1xpSXJtiMjjnKVCMJmxlHH93-ai0QxTw5QkhqtMxZEmuZSMSWEwVTzGlGRY5tFzLj7lXPS12J9oWVjA513WE05DgOsaD1RyzgyLDNERl0kaJxmhkaQZNpzRiFODIcZMbgaXNFVVOL9afu53gOHXRhpoHd---uFV5KHQnmAb-_z-_Pz-_Pz-_NOK6Z-tORRNZ5Hq659P8TRiDBphxlTEuIl0hkWEVcKgKkXwzFgu8zRX8s7K9tDFT7Cy_YY16ld7QZ_pBdUZzcTMFa40i7VvTVfQmqKXw__pvpF-a7atsX1PLVwfiOfXa3Sw4dBng9mzri0Xj_7wU1jb9V9-OKUEz3aLLEkSKhIOkapZalIlMOPYV-osUZTqWSmkKe0i4MuAr2fFgmBCcARnQlLKwiyOlMowzjmLZB5LCEEDvilDrziEl5FZu-gxyG5rgVgW1tlrIiSH_9pjzvJF53ZNu_irE20nZz3aRQ_1H2BdLe4">