https://gcc.gnu.org/bugzilla/show_bug.cgi?id=37262
--- Comment #4 from Martin Sebor <msebor at gcc dot gnu.org> ---
I confirm that there are no duplicated branch instructions in object code
emitted by GCC 6.0, although the branches that are there don't look quite
optimal.
I built the gcc-5-branch on powerpc64-linux and the duplicate instructions are
still there with the second test case compiled at -O2 (see below).
$ /build/gcc-5.x/gcc/xgcc -B /build/gcc-5.x/gcc -O1 -S -Wall -Wextra -Wpedantic
-o/dev/stdout -m32 t.c
.file "t.c"
.machine power4
t.c: In function ‘_bfd_xcoff_canonicalize_dynamic_reloc’:
t.c:15:1: warning: control reaches end of non-void function [-Wreturn-type]
}
^
.section ".text"
.align 2
.globl _bfd_xcoff_canonicalize_dynamic_reloc
.type _bfd_xcoff_canonicalize_dynamic_reloc, @function
_bfd_xcoff_canonicalize_dynamic_reloc:
cmpwi 0,3,0
bne 0,.L2 <<< branch
bne 0,.L6 <<< duplicate branch
cmplwi 7,4,2
bgt 7,.L2
.L6:
cmpwi 7,3,0
bne 7,.L2
cmplwi 7,4,2
bne 7,.L2
stwu 1,-16(1)
mflr 0
stw 0,20(1)
bl _bfd_abort
b .L1
.L2:
blr
.L1:
lwz 0,20(1)
mtlr 0
addi 1,1,16
blr
.size
_bfd_xcoff_canonicalize_dynamic_reloc,.-_bfd_xcoff_canonicalize_dynamic_reloc
.ident "GCC: (GNU) 5.3.1 20160130"
.section .note.GNU-stack,"",@progbits
