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<base href="https://bugs.llvm.org/">
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<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [Statepoint-VRegs] Dropped tied operand when folding unrelated memop"
href="https://bugs.llvm.org/show_bug.cgi?id=46916">46916</a>
</td>
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<tr>
<th>Summary</th>
<td>[Statepoint-VRegs] Dropped tied operand when folding unrelated memop
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<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>Common Code Generator Code
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>listmail@philipreames.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Found while working on something else, full test case copied below. Note that
after peephole-opt the def/use tied pairs have been broken. This is a
miscompile.
>From some quick digging, it appears to be a problem in foldPatchpoint in
lib/CodeGen/TargetInstInfo.cpp. What appears to be happening is we're folding
a load into a deopt operand and not preserving the tied operand information
when building the new instruction. Note that this *isn't* related to folding
gc operands themselves.
; RUN: llc -max-registers-for-gc-values=5
-stop-after=fixup-statepoint-caller-saved < %s
target datalayout = "e-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-pc-linux-gnu"
declare void @foo()
declare void @consume(i8 addrspace(1)*)
define void @test(i8 addrspace(1)* %a, i8 addrspace(1)* %b, i8 addrspace(1)*
%c, i8 addrspace(1)* %d, i8 addrspace(1)* %e, i8 addrspace(1)* %f, i8
addrspace(1)* %g, i8 addrspace(1)* %h) gc "statepoint-example" {
entry:
%safepoint_token = tail call token (i64, i32, void ()*, i32, i32, ...)
@llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @foo, i32
0, i32 0, i32 0, i32 0) ["gc-live" (i8 addrspace(1)* %a, i8 addrspace(1)* %b,
i8 addrspace(1)* %c, i8 addrspace(1)* %d, i8 addrspace(1)* %e, i8 addrspace(1)*
%f, i8 addrspace(1)* %g, i8 addrspace(1)* %h)]
%a1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 0, i32 0)
call void @consume(i8 addrspace(1)* %a1)
%b1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 1, i32 1)
call void @consume(i8 addrspace(1)* %b1)
%c1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 2, i32 2)
call void @consume(i8 addrspace(1)* %c1)
%d1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 3, i32 3)
call void @consume(i8 addrspace(1)* %c1)
%e1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 4, i32 4)
call void @consume(i8 addrspace(1)* %e1)
%f1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 5, i32 5)
call void @consume(i8 addrspace(1)* %f1)
%g1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 6, i32 6)
call void @consume(i8 addrspace(1)* %g1)
%h1 = call i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token
%safepoint_token, i32 7, i32 7)
call void @consume(i8 addrspace(1)* %h1)
ret void
}
declare token @llvm.experimental.gc.statepoint.p0f_i1f(i64, i32, i1 ()*, i32,
i32, ...)
declare token @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*,
i32, i32, ...)
declare i8 addrspace(1)* @llvm.experimental.gc.relocate.p1i8(token, i32, i32)</pre>
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