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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - always_inline is ignored with the new pass manager"
href="https://bugs.llvm.org/show_bug.cgi?id=46945">46945</a>
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<th>Summary</th>
<td>always_inline is ignored with the new pass manager
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<th>Product</th>
<td>clang
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<th>Version</th>
<td>trunk
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<th>Hardware</th>
<td>PC
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<th>OS</th>
<td>All
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<th>Status</th>
<td>NEW
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<th>Severity</th>
<td>normal
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<th>Priority</th>
<td>P
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<th>Component</th>
<td>C
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<th>Assignee</th>
<td>unassignedclangbugs@nondot.org
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<th>Reporter</th>
<td>denik@google.com
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<th>CC</th>
<td>blitzrakete@gmail.com, dgregor@apple.com, erik.pilkington@gmail.com, llvm-bugs@lists.llvm.org, richard-llvm@metafoo.co.uk
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<pre>Created <span class=""><a href="attachment.cgi?id=23804" name="attach_23804" title="2 cases representing the inline and dead code elimination issues.">attachment 23804</a> <a href="attachment.cgi?id=23804&action=edit" title="2 cases representing the inline and dead code elimination issues.">[details]</a></span>
2 cases representing the inline and dead code elimination issues.
QEMU v5.0 build fails with the new pass manager:
ld.lld: error: undefined symbol: qemu_build_not_reached
<span class="quote">>>> referenced by cputlb.c:0 (/h/git/qemu/accel/tcg/cputlb.c:0)
>>> accel/tcg/cputlb.o:(store_helper)</span >
The recent QEMU change introduces a sanity check for nested inline functions
with attribute "always_inline":
<a href="https://github.com/qemu/qemu/blob/9f1750ed68911bef069b5d9ba5cef8150972bcf1/include/qemu/compiler.h#L232">https://github.com/qemu/qemu/blob/9f1750ed68911bef069b5d9ba5cef8150972bcf1/include/qemu/compiler.h#L232</a>
<a href="https://github.com/qemu/qemu/blob/956ae3e9265fd36cb1c487cb3c868e906bd55897/accel/tcg/cputlb.c#L1962">https://github.com/qemu/qemu/blob/956ae3e9265fd36cb1c487cb3c868e906bd55897/accel/tcg/cputlb.c#L1962</a>
`objdump -t accel/tcg/cputlb.o` shows than "store_helper" is not inlined and
there is a reference to "qemu_build_not_reached".
Without the new pass manager the build passes ("store_helper" is inlined and
dead code with "qemu_build_not_reached" is eliminated).
Here are two test cases from creduce:
1. cputlb_inline.c which shows "store_helper" with "always_inline" not honored
by the new pass manager;
2. cputlb_deadcode.c - dead code is not eliminated by the new pass manager.
Steps to reproduce"
Compare `objdump -t test.o` from:
1. clang -c -O2 -o test1.o cputlb_inline.c
2. clang -c -O2 -o test2.o -fexperimental-new-pass-manager cputlb_inline.c
3. diff <(objdump -t test1.o) <(objdump -t test2.o)</pre>
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