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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [GlobalISel][AArch64] Calling convention for vectors incorrect on big-endian targets"
href="https://bugs.llvm.org/show_bug.cgi?id=35360">35360</a>
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<th>Summary</th>
<td>[GlobalISel][AArch64] Calling convention for vectors incorrect on big-endian targets
</td>
</tr>
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<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
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<th>Hardware</th>
<td>PC
</td>
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<th>OS</th>
<td>Linux
</td>
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<th>Status</th>
<td>NEW
</td>
</tr>
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<th>Severity</th>
<td>enhancement
</td>
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<th>Priority</th>
<td>P
</td>
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<th>Component</th>
<td>GlobalISel
</td>
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<th>Assignee</th>
<td>unassignedbugs@nondot.org
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</tr>
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<th>Reporter</th>
<td>oliver.stannard@arm.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
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<p>
<div>
<pre>Global-isel generates incorrect code when targeting big-endian AArch64 for this
code:
#include <arm_neon.h>
int32x2_t load_vector(int32x2_t *p) {
return *p;
}
Global-isel generates this:
// armclang --target=aarch64-arm-none-eabi -march=armv8-a -c callees.cpp -O0
-Wall -std=c++11 -mllvm -global-isel=true -mllvm -global-isel-abort=0
-mbig-endian -o - -S
_Z11load_vectorP11__Int32x2_t: // @_Z11load_vectorP11__Int32x2_t
// BB#0: // %entry
sub sp, sp, #16 // =16
str x0, [sp, #8]
ldr x0, [sp, #8]
ld1 { v0.2s }, [x0]
add sp, sp, #16 // =16
ret
With global-isel off, there is a rev64 instruction between the ld1 and the add,
which fixes up the endianness of the vector.</pre>
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