https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105193
Bug ID: 105193
Summary: Code divergence based on -fdump-tree-* since
r9-5080-gf7293b9dfab5e6e7
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ipa
Assignee: unassigned at gcc dot gnu.org
Reporter: marxin at gcc dot gnu.org
CC: hubicka at gcc dot gnu.org, marxin at gcc dot gnu.org
Target Milestone: ---
The following code diverges:
$ cat NodeImpl.ii
struct NodeImpl {
virtual bool isAttrImpl();
void deleteIf();
virtual int getOwnerDocument();
void unreferenced();
bool isOwned();
};
struct AttrImpl : NodeImpl {
bool isAttrImpl();
};
bool NodeImpl::isAttrImpl() { return false; }
NodeImpl *deleteIf_thisNode;
void NodeImpl::deleteIf() {
if (isOwned())
return;
isAttrImpl();
((AttrImpl *)deleteIf_thisNode)->getOwnerDocument();
}
void NodeImpl::unreferenced() { deleteIf(); }
$ g++ -O2 NodeImpl.ii -c -S -o 1.s -fdump-tree-all=/dev/null && g++ -O2
NodeImpl.ii -c -S -o 2.s && diff -u [12].s
--- 1.s 2022-04-07 11:43:05.995744783 +0200
+++ 2.s 2022-04-07 11:43:06.023744659 +0200
@@ -27,8 +27,10 @@
testb %al, %al
jne .L3
movq 0(%rbp), %rax
- movq %rbp, %rdi
- call *(%rax)
+ movq (%rax), %rax
+ cmpq $_ZN8NodeImpl10isAttrImplEv, %rax
+ jne .L10
+.L5:
movq deleteIf_thisNode(%rip), %rdi
popq %rbp
.cfi_remember_state
@@ -41,8 +43,16 @@
.L3:
.cfi_restore_state
popq %rbp
+ .cfi_remember_state
.cfi_def_cfa_offset 8
ret
+ .p2align 4,,10
+ .p2align 3
+.L10:
+ .cfi_restore_state
+ movq %rbp, %rdi
+ call *%rax
+ jmp .L5
.cfi_endproc
.LFE1:
.size _ZN8NodeImpl8deleteIfEv, .-_ZN8NodeImpl8deleteIfEv
