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* [Bug tree-optimization/46236] New: Local aggregate not eliminated
@ 2010-10-30 0:38 davidxl at gcc dot gnu.org
2010-10-30 18:20 ` [Bug tree-optimization/46236] " rguenth at gcc dot gnu.org
2021-08-10 17:46 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: davidxl at gcc dot gnu.org @ 2010-10-30 0:38 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46236
Summary: Local aggregate not eliminated
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassigned@gcc.gnu.org
ReportedBy: davidxl@gcc.gnu.org
CC: xinliangli@gmail.com
Simple Test case:
struct A {
int a[100];
};
const struct A aa = {1,1,1};
int foo(int i)
{
int s = 0;
struct A a;
a = aa;
s = a.a[i];
if (i > 5)
s+=a.a[i];
return s;
}
// Trunk gcc generates: (O2)
foo:
.LFB0:
.cfi_startproc
subq $280, %rsp
.cfi_def_cfa_offset 288
movl %edi, %edx
xorl %eax, %eax
leaq -120(%rsp), %rdi
cmpl $6, %edx
movl $50, %ecx
rep stosq
movl $1, -120(%rsp)
movl $1, -116(%rsp)
movl $1, -112(%rsp)
movslq %edx, %rax
movl -120(%rsp,%rax,4), %eax
leal (%rax,%rax), %ecx
cmovge %ecx, %eax
addq $280, %rsp
.cfi_def_cfa_offset 8
ret
// Trunk LLVM generates: (O2)
foo:
.Leh_func_begin0:
movslq %edi, %rcx
movl aa(,%rcx,4), %eax
cmpl $6, %ecx
jl .LBB0_2
addl %eax, %eax
.LBB0_2:
ret
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/46236] Local aggregate not eliminated
2010-10-30 0:38 [Bug tree-optimization/46236] New: Local aggregate not eliminated davidxl at gcc dot gnu.org
@ 2010-10-30 18:20 ` rguenth at gcc dot gnu.org
2021-08-10 17:46 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: rguenth at gcc dot gnu.org @ 2010-10-30 18:20 UTC (permalink / raw)
To: gcc-bugs
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=46236
--- Comment #1 from Richard Guenther <rguenth at gcc dot gnu.org> 2010-10-30 18:20:48 UTC ---
This is a dup of the PR that says we don't do aggregate copyprop.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug tree-optimization/46236] Local aggregate not eliminated
2010-10-30 0:38 [Bug tree-optimization/46236] New: Local aggregate not eliminated davidxl at gcc dot gnu.org
2010-10-30 18:20 ` [Bug tree-optimization/46236] " rguenth at gcc dot gnu.org
@ 2021-08-10 17:46 ` pinskia at gcc dot gnu.org
1 sibling, 0 replies; 3+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-10 17:46 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=46236
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
Last reconfirmed|2018-04-22 00:00:00 |2021-8-10
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-08-10 17:46 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2010-10-30 0:38 [Bug tree-optimization/46236] New: Local aggregate not eliminated davidxl at gcc dot gnu.org
2010-10-30 18:20 ` [Bug tree-optimization/46236] " rguenth at gcc dot gnu.org
2021-08-10 17:46 ` pinskia at gcc dot gnu.org
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