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<base href="https://bugs.llvm.org/">
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [RISCV] wrong vector register alloc in vector instruction"
href="https://bugs.llvm.org/show_bug.cgi?id=50813">50813</a>
</td>
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<tr>
<th>Summary</th>
<td>[RISCV] wrong vector register alloc in vector instruction
</td>
</tr>
<tr>
<th>Product</th>
<td>new-bugs
</td>
</tr>
<tr>
<th>Version</th>
<td>unspecified
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>new bugs
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>tangxingxin1008@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>There is a wrong vector instruction will be produced:
vrgather.vv v25, v25, v25
in the below test case.
>From the the vector spec, there is a rule: for any vrgather instruction, the
destination vector register group cannot overlap the source vector register
group.
vrgather-test.ll:
declare <vscale x 8 x i8> @llvm.riscv.vrgather.vv.nxv8i8.i64(
<vscale x 8 x i8>,
<vscale x 8 x i8>,
i64);
define dso_local signext i32 @intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8()
nounwind {
entry:
%0 = alloca <vscale x 8 x i8>, align 8
%1 = call <vscale x 8 x i8> @llvm.riscv.vrgather.vv.nxv8i8.i64(
<vscale x 8 x i8> undef,
<vscale x 8 x i8> undef,
i64 undef)
store volatile <vscale x 8 x i8> %1, <vscale x 8 x i8>* %0, align 8
ret i32 0
}
llc -mtriple=riscv64 -mattr=+experimental-v,+d,+experimental-zfh
-verify-machineinstrs vrgather-test.ll -o vrgather-test.s
vrgather-test.s:
.text
.attribute 4, 16
.attribute 5, "rv64i2p0_f2p0_d2p0_v0p10_zfh0p1"
.file "vrgather-test.ll"
.globl intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8 # -- Begin function
intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8
.p2align 2
.type intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8,@function
intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8: #
@intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8
# %bb.0: # %entry
addi sp, sp, -16
csrr a0, vlenb
sub sp, sp, a0
vsetvli zero, a0, e8,m1,ta,mu
vrgather.vv v25, v25, v25
addi a0, sp, 16
vs1r.v v25, (a0)
mv a0, zero
csrr a1, vlenb
add sp, sp, a1
addi sp, sp, 16
ret
.Lfunc_end0:
.size intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8,
.Lfunc_end0-intrinsic_vrgather_vv_nxv8i8_nxv8i8_nxv8i8
# -- End function
.section ".note.GNU-stack","",@progbits</pre>
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