<table border="1" cellspacing="0" cellpadding="8">
    <tr>
        <th>Issue</th>
        <td>
            <a href=https://github.com/llvm/llvm-project/issues/61579>61579</a>
        </td>
    </tr>

    <tr>
        <th>Summary</th>
        <td>
             [optimization] gcc generate better code than clang base on predicate SVE
        </td>
    </tr>

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

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

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

<pre>
    * test case: https://gcc.godbolt.org/z/d3n1aPanv
```
int check(char* mask, float *result, int n) {
    int count = 0;
    for(int j = 0; j < n; j++){
        if((mask[j] == 0) && (result[j] != 2.0)){
 count ++;
        }
    }
    return count;
}
```
*  gcc's kernel loop
```
.L3:
        ld1b    z1.s, p1/z, [x0, x3]
 cmpeq   p0.b, p1/z, z1.b, #0
        ld1w    z1.s, p0/z, [x1, x3, lsl 2]
        add     x3, x3, x4
        fcmne   p0.s, p0/z, z1.s, z3.s
        and     p0.b, p0/z, p1.b, p1.b
        whilelo p1.s, w3, w2
        add     z0.s, p0/m, z0.s, z2.s
        b.any .L3
```
* llvm's kernel loop, llvm's version is more complex on the updating of the Predicate registers
```
.LBB0_2: // =>This Inner Loop Header: Depth=1
        ld1b    { z3.s }, p1/z, [x0, x8]
        cmpeq   p1.s, p1/z, z3.s, #0
        ld1w    { z3.s }, p1/z, [x1, x8, lsl #2]
        add     x8, x8, x10
        not p3.b, p0/z, p1.b        --- 
        fcmne   p2.s, p0/z, z3.s, z1.s
 mov     p2.b, p3/m, p3.b     ---
        and     p2.b, p1/z, p1.b, p2.b
        whilelo p1.s, x8, x9
        add     z0.s, p2/m, z0.s, z2.s
        b.mi    .LBB0_2
```
</pre>
<img width="1px" height="1px" alt="" src="http://email.email.llvm.org/o/eJyMVU1v4zYQ_TXjyyCCOLRs-aBDHK_RAntYoEWvBSVRHwlFqiSdZP3rC1KyEztxdgMhlMg38x45b0zhXN9qKQvItpDtFuLgO2OL56ZumkVp6p8F0D166TxWwkng99h5Pzrg90B7oH1bVUlr6tIonxjbAu2PQPuaayZ-CP0M6Q7Se1il8xM_e-2x6mT1BJRXnbCBYhDuCegBG2WER6B7K91B-TAV4Bpog7DeTgkQMc5W5qA9At9hCvzdWmMsUB4Qj-fV-PqAOr4CbeOzuUgZ0zZAOVAe9WTbR8h2IcWUJWigFdAKgfJZ4AlDLGAoCaiLxLPIiZFf0cF69zZx8WGlP1g9RZ_DzoirEw0niG1VAa0dPkmrpUJlzPgpOPnOQ_kudKialWE8ssSFMx_ZVMkHhGz7moaXVw7ZSV81jPI_RBzTpLyEH9k0A8TTDxQvFxTpewo2U9ADKqeQ3rjmP1HXcZww8__lJaapBi0nWVcUJ9IjT9xVXj3lPW_lHDOy0-aS8jLmpeuVVCasxKwvUc0Lfa74-F7NEFXMM0e6VlMmQv_EUKFbZVbqefhQ5nBqp_lnaV1vNPYOB2MlVmYYlXxFo9F3Eg9jLXyvWzRN_P5hZd1Xwku0su2dl9bdcM12m_5L4Rdg6vypLb793fUO_9RaWvxuzIh_SFFLG2A7OfoO-I59bjVYb2M5ou1vWC7_YIOz8z4YNZb2S-d9zchmxtmBQPwLE-Zv4Fd2RaeNx5F_5qYT4u7uDm84lz44d95WdPAUM5jnybI0k_CTsQLtieGGzem6Y882p1_ZfN7v5hc2p9-x-dCH8WSqS8Mt6oLXG74RC1mw1XqzTDnLaNEVZcbyrNnkq3pZsaZkeZktm2XJ1yWVacnqRV9QSjzlxBhlxCkRPGuaTVOnJWuW5ZLBMpWD6FUS2iVcWIveuYMsVixbbxZKlFK5eBcSafmCcREoGGFhixBzVx5aB8tU9c67tyy-90oWwUdm9P3QH4XvjQ4XQ1tV2EotbWixUnovLVamlug7obFSQrdYCidDf47nXvzrn2-Lg1XF1WXb--5QJpUZgPZTw8fhbrTmUVYeaB8VO6B93NH_AQAA__-fLg9E">