<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/115446>115446</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
            [RISC-V] Possible Miscompilation by Indexed Segment Load-Store Intrinsics
        </td>
    </tr>

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

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

    <tr>
      <th>Reporter</th>
      <td>
          Yibo-He
      </td>
    </tr>
</table>

<pre>
    In the following code with rvv intrinsics, I load data from a to b.
The index of `__riscv_vsoxseg5ei8_v_f64m1x5` is obtained from the result of `__riscv_vid_v_u8mf8`(*=8), and i think the result should be the same with `__riscv_vsseg5e64_v_f64m1x5` (if this is a misunderstanding, please tell me).
However, values of vector a are not equal to values in vector b after the for loop.
```
#include <riscv_vector.h>
#define dataLen 20
uint8_t idx[dataLen];
double a[dataLen]; double b[dataLen];
int main(){
  for (int i = 0; i < dataLen; ++i) { a[i] = i * 10.0; }
  for (int i = 0; i < dataLen; ++i) { b[i] = 0; }
  int placeholder0 = dataLen;
  double* ptr_a = a;
  double* ptr_b = b;
  for (size_t vl; placeholder0 > 0; placeholder0 -= vl * 5){
    vl = __riscv_vsetvl_e64m1(placeholder0);
    vfloat64m1x5_t va = __riscv_vlseg5e64_v_f64m1x5(ptr_a, vl);
    vuint8mf8_t vidx = __riscv_vsll_vx_u8mf8(__riscv_vid_v_u8mf8(vl), 3, vl);
 __riscv_vsoxseg5ei8_v_f64m1x5(ptr_b, vidx, va, vl);
    ptr_a += vl * 5;
    ptr_b += vl * 5;
  }
  for(int i=0; i<dataLen; ++i){ if(a[i]!=b[i]){ __builtin_printf("a[%d]=%lf, b[%d]=%lf\n", i, a[i], i, b[i]); } }
  return 0;
}
```

Result:
```
a[1]=10.000000, b[1]=50.000000
a[2]=20.000000, b[2]=60.000000
a[3]=30.000000, b[3]=70.000000
a[4]=40.000000, b[4]=80.000000
a[5]=50.000000, b[5]=90.000000
a[6]=60.000000, b[6]=0.000000
a[7]=70.000000, b[7]=0.000000
a[8]=80.000000, b[8]=0.000000
a[9]=90.000000, b[9]=0.000000
a[11]=110.000000, b[11]=150.000000
a[12]=120.000000, b[12]=160.000000
a[13]=130.000000, b[13]=170.000000
a[14]=140.000000, b[14]=180.000000
a[15]=150.000000, b[15]=190.000000
a[16]=160.000000, b[16]=0.000000
a[17]=170.000000, b[17]=0.000000
a[18]=180.000000, b[18]=0.000000
a[19]=190.000000, b[19]=0.000000
```

The above results appear in LLVM 18.1.8 and 19.1.0 (with qemu 9.1.0).
```
$ clang --version
clang version 19.1.0
Target: riscv64-unknown-linux-gnu
Thread model: posix
InstalledDir: ...
$ qemu-riscv64 --version
qemu-riscv64 version 9.1.0
Copyright (c) 2003-2024 Fabrice Bellard and the QEMU Project developers
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJykV8Fu27oS_Rp6M7AhUpYlLbyI7QYNkAJ97XsF3kqgJMrmLUW6JKW49-svSFGOLTnd3CBI4pk5w8M5Q2ZIjeFHydgWJTuUHBa0syelt__npVp-ZotS1b-3LxLsiUGjhFBvXB6hUjWDN25PoPseuLSaS8Mrg8geXkAoWkNNLYVGqxYoWAXlCkUHFD3998SAy5pdQDWANlFRaG6qvuiNuhh2TBjPir5oNusWXxK0iYAbUKWlXLJ6SOeYaGY6YacpeF30RZe1TYY2ESIZIk8oPmSI5I4XlTVwsCcuf97mMCfViRpK5o2GtmFjd9w8s836nhkiGW9cQuNIUmi56WTNtLFU1lwe3aJnwahhYJkQ0DJE8lCGz-qN9Uy7kJ6Kjhm3l55VVmmgQDUDqSywXx0VrnohhssxpgTaWKaDLBqEUueQ2u19-B4-kpjLSnQ1AxTvw4Z8ktUJxZ-uQTVruGRetlcmgQR4x6XNCgu8vqBkF7woOaB4NwTUqisFAzr1QnCUj2FcWmgpl16mHKXBDH43rrLSAgcUHyByydyf-5GcMyCyQ2THEckBpTu_PEfJwSM4IPIEOFp5KEoP_y53eZt7mtLlOgtasZMSNdORD3rPNYYNxXC0zlYX1EfRD_2l95c3_sDc8L9ZYaEXjsVk2U8Dtzvr0uXpha9Hcl9n8Pb4AO9dzmwvCuYaHJHsNo9DxrfIRihqh5Pg6ND7RGJ-XEjm9-37XczS-SZrG9dnPa8vE1pCFP0lnGuSPTrtJBuSkj3ED5b48x0zUCs9znW5P5KPiQbtyO6urNOI8g8R98049iKKD0Mnonj_sA9dG_IGkWzsc0Qwig_l9ZOPKIqy48JyWZw1l7bxZ4s4CCJJ7U_fAZFENG535QNzspeIEOfl_sa8pg-G2_WGY3C7Ic1sp6XvwnCrjL7pleR_fvP3L4qfHsa4tfHAzR1k_zVSCPbkar8iyOAhU0Swb-aIePDEU0Swp3PEevCsp4hgz-aIZMo3III9nyM2U74BEexzQDqlGwDpR4BsyjYAso8A-ZRsAOQfAfAo31y_0fNAQRykwjMNr54HKuIgF57pePU8UBIHyfBMy6vngZo4mbEfUaPngaJ4M2M_oj4UFacz7iPmQ11xNmM-Yj6UFucz3iPmoboPj7Mb7Gip-nGwMkDPZ0a1G1peX398AZyt8CrzYxjOV3jlByg_av1ibQfe9D4gzaaYNVSCyiMslz3This5OAZjMIXEgRDVR-buF_C3_2a97ORPqd7kUnDZXZZH2Y3MNaM1tKpmwoWfleGXwfUijaVCsPrAtXOtVqt3Po72MuSe0rrzjexuyO3V-bfmx5N1RajcpEGiKF6SiKzhmZaaVwx2TAiqa18xN-f959OX_8FXrf5ilYWa9UyoM9NmUq9FvY3rPM7pgm1xGuMoSfM0XZy2KY7YJksqkrC4TOqkyZN0TaOmajY5ruN4wbdueYyjLMrJBqerqowbGldpmmc4bRhB64i1lIuVEH27Uvq44MZ0bItxsl5vFoKWTJjxHaG3LmpZdkeD1pHgxpp3nOVW-BfHt5fv--UPN1x9VcZwNzB-4aZS7ZkLal3Ryt_w4t4LrIbv7NgyaeFV0Xr53SrN4OX69Fh0WmxP1p6N-5dCnhF5PnJ76spVpVpEnt3a4dfyPBQRkWe_AYPIc9hDvyX_BAAA__8P_oXg">