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From: "absoler at smail dot nju.edu.cn" <gcc-bugzilla@gcc.gnu.org> To: gcc-bugs@gcc.gnu.org Subject: [Bug rtl-optimization/114800] New: redundant set-zero when initiate a struct Date: Mon, 22 Apr 2024 08:27:18 +0000 [thread overview] Message-ID: <bug-114800-4@http.gcc.gnu.org/bugzilla/> (raw) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114800 Bug ID: 114800 Summary: redundant set-zero when initiate a struct Product: gcc Version: 13.2.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: rtl-optimization Assignee: unassigned at gcc dot gnu.org Reporter: absoler at smail dot nju.edu.cn Target Milestone: --- I found a weird case that ``` struct thresh_restart { int *f0; int f1; int f2; int f3; }; int arr[10]; void __attribute__((noinline)) foo(struct thresh_restart *p) { arr[0] = p->f3; arr[1] = p->f1; } void func(int *b) { struct thresh_restart tr = { .f0 = b, .f1 = 1, .f2 = 2, .f3 = 3, }; foo(&tr); } ``` such code is compiled as: (gcc-13.2.0 -O2, regression [11/12/13/trunk]) https://godbolt.org/z/rb4o6xc7E ``` func(int*): sub $0x28,%rsp pxor %xmm0,%xmm0 mov %rsp,%rdi movaps %xmm0,(%rsp) movq $0x0,0x10(%rsp) # redundancy movl $0x1,0x8(%rsp) movl $0x3,0x10(%rsp) call 401120 <foo(thresh_restart*)> add $0x28,%rsp ret ```
next reply other threads:[~2024-04-22 8:27 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-04-22 8:27 absoler at smail dot nju.edu.cn [this message] 2024-04-22 9:10 ` [Bug rtl-optimization/114800] " xry111 at gcc dot gnu.org 2024-04-22 23:33 ` [Bug tree-optimization/114800] " pinskia at gcc dot gnu.org 2024-04-22 23:35 ` [Bug tree-optimization/114800] DSE does not remove set-zero which is partial redundant pinskia at gcc dot gnu.org 2024-04-22 23:40 ` [Bug tree-optimization/114800] DSE does not remove set-zero which is partial redundant with respect to mod-ref pinskia at gcc dot gnu.org
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