https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103465
--- Comment #5 from Martin Liška <marxin at gcc dot gnu.org> ---
> However, still talking about the current master only, I see a difference
> with -O3, when I try on the repro example from Bug 103274 and -O3:
>
> x86_64-w64-mingw32-gcc -c -S -O3 -fno-reorder-blocks-and-partition a.c -o
> nropt.s
>
> x86_64-w64-mingw32-gcc -c -S -O3 -freorder-blocks-and-partition a.c -o ropt.s
> x86_64-w64-mingw32-gcc -c -S -O3 a.c -o noopt.s
>
> All of these assembler files are different (and from my non-expert reading,
> noopt.s uses the optimization and does have the invalid unwind information
> as reported in Bug 103274). Is the optimization correctly dropped also with
> -O3 only?
Hmmm, I've just tested the same with the locally built cross-compiler:
~/Programming/gcc/configure --enable-languages=c,c++
--prefix=/home/marxin/bin/gcc --disable-multilib --enable-host-shared
--disable-libsanitizer --enable-valgrind-annotations --disable-bootstrap
--target=x86_64-w64-mingw32
and it works fine, all 3 assembly files are identical.
cat 1.s
.file "pr103274.c"
.text
.section .rdata,"dr"
.LC0:
.ascii "factor\0"
.text
.p2align 4
.globl _Z5dummyP7SEXPREC
.def _Z5dummyP7SEXPREC; .scl 2; .type 32; .endef
.seh_proc _Z5dummyP7SEXPREC
_Z5dummyP7SEXPREC:
.LFB2:
pushq %r13
.seh_pushreg %r13
pushq %r12
.seh_pushreg %r12
pushq %rbp
.seh_pushreg %rbp
pushq %rdi
.seh_pushreg %rdi
pushq %rsi
.seh_pushreg %rsi
pushq %rbx
.seh_pushreg %rbx
subq $40, %rsp
.seh_stackalloc 40
.seh_endprologue
movq %rcx, %r12
call _Z11mypredicateP7SEXPREC
testl %eax, %eax
jne .L21
.L2:
movq .refptr.R_NilValue(%rip), %rax
movq (%rax), %rax
addq $40, %rsp
popq %rbx
popq %rsi
popq %rdi
popq %rbp
popq %r12
popq %r13
ret
.p2align 4,,10
.p2align 3
.L21:
movq %r12, %rcx
call _Z11mygetattribP7SEXPREC
movq %rax, %rcx
movq %rax, %r13
call _Z8mylengthP7SEXPREC
movl %eax, %ebp
testl %eax, %eax
jle .L2
movl %eax, %r12d
movl $1, %esi
leaq .LC0(%rip), %rdi
jmp .L6
.p2align 4,,10
.p2align 3
.L8:
movq %rax, %rsi
.L6:
movzbl 0(%r13), %ebx
andl $1, %ebx
je .L3
leal -1(%rsi), %edx
movq %r13, %rcx
call _Z11myaltstringP7SEXPRECi
movq %rdi, %rdx
movq %rax, %rcx
addq $8, %rcx
call _Z6strcmpPKcS0_
testl %eax, %eax
je .L5
.L22:
cmpq %r12, %rsi
je .L2
leaq 1(%rsi), %rax
testb %bl, %bl
jne .L8
movslq %esi, %rsi
.L7:
movq 8(%r13,%rsi,8), %rax
movq %rdi, %rdx
leaq 8(%rax), %rcx
call _Z6strcmpPKcS0_
testl %eax, %eax
je .L5
addq $1, %rsi
cmpl %esi, %ebp
jg .L7
jmp .L2
.p2align 4,,10
.p2align 3
.L3:
movq 0(%r13,%rsi,8), %rcx
movq %rdi, %rdx
addq $8, %rcx
call _Z6strcmpPKcS0_
testl %eax, %eax
jne .L22
.L5:
call _Z11myerrorcallv
nop
.seh_endproc
.ident "GCC: (GNU) 12.0.0 20211209 (experimental)"
.def _Z11mypredicateP7SEXPREC; .scl 2; .type 32;
.endef
.def _Z11mygetattribP7SEXPREC; .scl 2; .type 32;
.endef
.def _Z8mylengthP7SEXPREC; .scl 2; .type 32; .endef
.def _Z11myaltstringP7SEXPRECi; .scl 2; .type 32;
.endef
.def _Z6strcmpPKcS0_; .scl 2; .type 32; .endef
.def _Z11myerrorcallv; .scl 2; .type 32; .endef
.section .rdata$.refptr.R_NilValue, "dr"
.globl .refptr.R_NilValue
.linkonce discard
.refptr.R_NilValue:
.quad R_NilValue
