https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104180
Bug ID: 104180 Summary: [10/11/12 Regression] '-fcompare-debug' failure (length) w/ -O1 Product: gcc Version: 12.0 Status: UNCONFIRMED Keywords: compare-debug-failure Severity: normal Priority: P3 Component: debug Assignee: unassigned at gcc dot gnu.org Reporter: asolokha at gmx dot com Target Milestone: --- g++ 12.0.0 20220109 snapshot (g:90045c5df5b3c8853e7740fb72a11aead1c489bb) fails -fcompare-debug check when compiling the following testcase, reduced from gcc/testsuite/gcc.dg/torture/pr89223.c, w/ -O1: int a[5]; void c () { unsigned int b; for (b = 3; ; b--) a[b] = ({ a[b + 1]; }); } % g++-12.0.0 -O1 -fcompare-debug -c lluhupiv.c g++-12.0.0: error: lluhupiv.c: '-fcompare-debug' failure (length) --- lluhupiv.c.gkd 2022-01-22 15:27:16.168639041 +0700 +++ lluhupiv.gk.c.gkd 2022-01-22 15:27:16.239634334 +0700 @@ -33,7 +33,7 @@ (nil)) (insn # 0 0 3 (set (mem:SI (plus:DI (mult:DI (reg:DI 2 cx [orig:87 b ] [87]) (const_int 4 [0x4])) - (reg/f:DI 5 di [86])) [ a[b_3]+0 S4 A32]) + (reg/f:DI 5 di [86])) [ MEM <int[5]> [(int *)&a][b_3]+0 S4 A32]) (reg:SI 4 si [orig:82 _2 ] [82])) "lluhupiv.c":9:10# {*movsi_internal} (expr_list:REG_DEAD (reg:SI 4 si [orig:82 _2 ] [82]) (expr_list:REG_DEAD (reg:DI 2 cx [orig:87 b ] [87])