https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100469
Bug ID: 100469
Summary: [11/12 Regression] -fcompare-debug failure (length)
with -O2 -fno-tree-dse -fno-tree-forwprop
-fno-tree-tail-merge
--param=sccvn-max-alias-queries-per-access=0
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
CC: aoliva at gcc dot gnu.org
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Created attachment 50773
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50773&action=edit
auto-reduced testcase (from OpenTTD sources)
Compiler output:
$ x86_64-pc-linux-gnu-gcc -O2 -fno-tree-dse -fno-tree-forwprop
-fno-tree-tail-merge --param=sccvn-max-alias-queries-per-access=0
-fcompare-debug testcase.C -save-temps
x86_64-pc-linux-gnu-gcc: error: testcase.C: '-fcompare-debug' failure (length)
$ diff a-testcase.C.gkd a-testcase.gk.C.gkd
13a14,15
> (note # 0 0 NOTE_INSN_DELETED)
> (note # 0 0 NOTE_INSN_DELETED)
15,16c17,18
< (mem:DI (reg:DI 4 si [89]) [ MEM[(const struct S &)s_2(D)].m+0 S8
A64])) "testcase.C":6:11# {*movdi_internal}
< (expr_list:REG_DEAD (reg:DI 4 si [89])
---
> (mem:DI (reg:DI 4 si [90]) [ MEM[(const struct S &)s_2(D)].m+0 S8
> A64])) "testcase.C":6:11# {*movdi_internal}
> (expr_list:REG_DEAD (reg:DI 4 si [90])
19c21
< (set (reg:DI 2 cx [90])
---
> (set (reg:DI 2 cx [91])
26c28
< (reg:DI 5 di [88])) "testcase.C":26:1# {*movdi_internal}
---
> (reg:DI 5 di [89])) "testcase.C":26:1# {*movdi_internal}
36c38
< (reg:DI 2 cx [90]))) "testcase.C":21:32# {*movdicc_noc}
---
> (reg:DI 2 cx [91]))) "testcase.C":21:32# {*movdicc_noc}
38c40
< (expr_list:REG_DEAD (reg:DI 2 cx [90])
---
> (expr_list:REG_DEAD (reg:DI 2 cx [91])
$ x86_64-pc-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=/repo/gcc-trunk/binary-latest-amd64/bin/x86_64-pc-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/repo/gcc-trunk/binary-trunk-r12-581-20210507001633-gcfe82a0cbe7-checking-yes-rtl-df-extra-amd64/bin/../libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /repo/gcc-trunk//configure --enable-languages=c,c++
--enable-valgrind-annotations --disable-nls --enable-checking=yes,rtl,df,extra
--with-cloog --with-ppl --with-isl --build=x86_64-pc-linux-gnu
--host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu
--with-ld=/usr/bin/x86_64-pc-linux-gnu-ld
--with-as=/usr/bin/x86_64-pc-linux-gnu-as --disable-libstdcxx-pch
--prefix=/repo/gcc-trunk//binary-trunk-r12-581-20210507001633-gcfe82a0cbe7-checking-yes-rtl-df-extra-amd64
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 12.0.0 20210507 (experimental) (GCC)
