https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100253
Bug ID: 100253
Summary: [10/11/12 Regression] wrong code with -O2
-fno-tree-bit-ccp -ftree-slp-vectorize (unaligned
movdqa)
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: wrong-code
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: zsojka at seznam dot cz
Target Milestone: ---
Host: x86_64-pc-linux-gnu
Created attachment 50672
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50672&action=edit
testcase
Output:
$ x86_64-pc-linux-gnu-g++ testcase.C -O2 -fno-tree-bit-ccp -ftree-slp-vectorize
$ ./a.out
Segmentation fault
Program received signal SIGSEGV, Segmentation fault.
0x00000000004011aa in S::operator= (this=0x404120 <s>) at testcase.C:7
7 struct S
(gdb) disas
Dump of assembler code for function main():
0x0000000000401180 <+0>: push %rbp
0x0000000000401181 <+1>: mov $0x404120,%edi
0x0000000000401186 <+6>: push %rbx
0x0000000000401187 <+7>: sub $0x8,%rsp
0x000000000040118b <+11>: movsbq 0x2f2d(%rip),%rbp # 0x4040c0 <c>
0x0000000000401193 <+19>: shl $0x6,%rbp
0x0000000000401197 <+23>: lea 0x4040e0(%rbp),%rsi
0x000000000040119e <+30>: call 0x4014e0
<_ZNSt6vectorIS_I1TSaIS0_EESaIS2_EEaSERKS4_>
0x00000000004011a3 <+35>: movzbl 0x4040f8(%rbp),%eax
=> 0x00000000004011aa <+42>: movdqa 0x404109(%rbp),%xmm0
0x00000000004011b2 <+50>: movdqa 0x4040f9(%rbp),%xmm1
0x00000000004011ba <+58>: mov %al,0x2f78(%rip) # 0x404138
<s+24>
0x00000000004011c0 <+64>: xor %eax,%eax
0x00000000004011c2 <+66>: movups %xmm1,0x2f70(%rip) # 0x404139
<s+25>
0x00000000004011c9 <+73>: movups %xmm0,0x2f79(%rip) # 0x404149
<s+41>
0x00000000004011d0 <+80>: add $0x8,%rsp
0x00000000004011d4 <+84>: pop %rbx
0x00000000004011d5 <+85>: pop %rbp
0x00000000004011d6 <+86>: ret
