<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/88834>88834</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [RISC-V][SLPVectorizer] rv64gcv miscompile 
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          patrick-rivos
      </td>
    </tr>
</table>

<pre>
    Testcase:
```c
signed char b = 1;
int c = 1;
int d[11];
char e[11];
unsigned *f = (unsigned *) d;
int main() {
  d[5] = -1868904051;
  for (int i = 0; i < 8; i += c)
 e[i] = ({
      long j = f[i];
      b > j ? b : j;
    });
 __builtin_printf("%hhd\n", e[5]);
}
```

Commands:
```
/scratch/tc-testing/tc-apr-15/build-rv64gcv/build-llvm-linux/bin/clang -march=rv64gcv -flto -O1 red.c -o user-config.out -fno-strict-aliasing
> /scratch/tc-testing/tc-apr-15/build-rv64gcv/bin/qemu-riscv64 user-config.out
-115
/scratch/tc-testing/tc-apr-15/build-rv64gcv/build-llvm-linux/bin/clang -march=rv64gcv -flto -O2 red.c -o user-config.out -fno-strict-aliasing
> /scratch/tc-testing/tc-apr-15/build-rv64gcv/bin/qemu-riscv64 user-config.out
1
```

Reduced LLVM IR:
```llvm ir
target datalayout = "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128"
target triple = "riscv64-unknown-linux-gnu"

@d = global [11 x i32] zeroinitializer
@e = global [11 x i8] zeroinitializer
@.str = constant [6 x i8] c"%hhd\0A\00"

define i32 @main() #0 {
for.body.preheader:
  store i32 -1868904051, ptr getelementptr inbounds ([11 x i32], ptr @d, i64 0, i64 5), align 4
  %conv.4 = zext i32 0 to i64
  %cond.4 = tail call i64 @llvm.smax.i64(i64 %conv.4, i64 0)
 %conv5.4 = trunc i64 %cond.4 to i8
  store i8 %conv5.4, ptr getelementptr inbounds ([11 x i8], ptr @e, i64 0, i64 4), align 1
  %0 = load i32, ptr getelementptr inbounds ([11 x i32], ptr @d, i64 0, i64 5), align 4
 %conv.5 = zext i32 %0 to i64
  %cond.5 = tail call i64 @llvm.smax.i64(i64 %conv.5, i64 1)
  %conv5.5 = trunc i64 %cond.5 to i8
  store i8 %conv5.5, ptr getelementptr inbounds ([11 x i8], ptr @e, i64 0, i64 5), align 1
  %1 = load i8, ptr getelementptr inbounds ([11 x i8], ptr @e, i64 0, i64 5), align 1
  %conv8 = zext i8 %1 to i32
  %call = tail call i32 (ptr, ...) @printf(ptr @.str, i32 %conv8)
  ret i32 0
}

; Function Attrs: nocallback nofree nosync nounwind speculatable willreturn memory(none)
declare i64 @llvm.smax.i64(i64, i64) #1

declare i32 @printf(ptr, ...)

; uselistorder directives
uselistorder ptr @llvm.smax.i64, { 1, 0 }

attributes #0 = { "target-features"="+64bit,+v" }
attributes #1 = { nocallback nofree nosync nounwind speculatable willreturn memory(none) }
```
Godbolt showing the optimization: https://godbolt.org/z/7EE4GhzsP

Found via fuzzer.
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJzMV1tv2zwS_TX0y0CCREm28uAHX-KiQBdbtIu-FhQ1ktlSpJeknMS_fkFKtmWn6aIf-l2MQOFtZg7PIUcjZq1oFeKSFGtSbGesd3ttlgfmjODfIyOO2s4qXb8s_4PWcWaRZCuSbEmyIvNk-ONDPziqge-ZgQpItoWUZOthTigH_AdjNSnWaUqK7WU0mOOr4V6N7gldNcERoeV0kNAHqG98d0woQks_QRbjOISIBSm2wUeUlvPyIcmT4goLoNHGe_c-RFiWkGwdmhsoxyZd-wlO6MNo5SGLs18f9hrS_6RWLXwLk824chLR_zxlj2HJLrRX8O1mBVlsfbTL0NevVS-kE-rrwQjlmrBVSmix39ek2KjQ2QRcfr9TW-_qVsKxG54b3XVM1fa10GOX7iw3zPE9oTvHI4fWCdUOHXYwUVoQuvPg6sgc53nLj5e-lMcukkL1z37I67PjkqkWoo4ZvifZdrSAqJFOQ_TvFAzWMYdIQ2_RRFyrRrSx7h1EjdKR9QfVRUwKZj2KAWL2CH8QZsD0X-z6yAjLj_P8PuwQIUrT4u-gg_4z6Uh_cp4-Yd1zrOHDhy__gvefXh8rzwIIM4w6Zlp0UDPHJHvx-xouFMWoI9kKowPJVvM8PCJxaaS0JNkqpWWkMjqMfU6HGzF164w4SDy7HLcU9eq70k9qUCJqVX8xG595UgebVuqKSQjZCZ5BZNTf-BMaLZRwgklxQnOxwR_alD8zia0zwYprZR1TztvNL2Z8esOTlX8kd1hrbIRCDw1InkxzIM2SayJstIl9Wo8PBvfIajQXXQCs02ZwMU2QdAMHZ6BFhxI7VM73hKp0r2obUt4NLef1njzfFvMcknOj8OmIboBJ0SrIz4EJLbhWxzgPHJzw2QUUCTjtzW6X1eMyx4QEzqQMnkkezlNsO_YcextahuGz5wmUc-oe54qzP9MrDlcjH8fHL-_oKSeGv0BOecsNvuImv-EmnWw6CfikZnXg-M8X5MxacatHgPJjSYpfl6Q4Y0ivklypLd7QpPh_mhS_U5PiTU3SiSblXxPS76-cKFIOODwfGZ2u8wLcyRHUKw_OeNdxHIfMkCeXEmKE4_NQADKoHSJO1DE4Xsz7emJ83axh1yvuhFawcs74UgKU9ggqxr-D0o1BBKXti-KgdK-ehKrBHpD3kjlWSYQnIaVB1xsFHXbavBBaKq3wgqJGLpnX_M0TNjI5Jr_0NkuOxkOanG7_Ssz9nnqLUviDVqOBWhjkThzRjgXqdHJk8Q7TxqdfCIk0gTvOmHNGVL1DOyZq_4ZarP1banh1RQ0y1xu0Pt9n2_AiWM_zSjhCN4Suj4TSq9Nbd-nF3e8TAd4qIt_putLSgd3rJ6FacHsEfXCiEyfmT4Q_C3vnDqG-pDtCd-1gEWvjy5ETobvF42P-bn-yH6cU7fwlgqNg0PSnE5p4Vi-z-iF7YDNcpos0o9kiWWSz_bLIGM2wqOtFShFTnNOqonlRZE3esAyrmVjShOZJns6TLE3TLE4ekrJZlA3lySIv5nN_IzsmZBwk1KadCWt7XJZlmeUzySqUNnwyUarwCcKkl6TYzswyVHVV31p_BIR19urFCSfDt9an95830RefA4r15w8fvyB32oRSoNjCuejrhOW6OwiJMOuNXN7RJty-r2KuO0J3PsL4LzoY_Q25I3QXcFlCdwH3_wIAAP__SyX95g">