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Hi Mark<br>
<br>
Does this help?<br>
It calls a function __dynamic_cast and puts the result in sp #120
which must be the location of dce. I can't see what __dynamic_cast
is doing.<br>
<br>
Peter<br>
<br>
<u>the source</u><br>
<br>
795 void StandardSettingDialog::customEvent(QEvent *event)<br>
796 {<br>
797 if (event->type() == DialogCompletionEvent::kEventType)<br>
798 {<br>
799 auto dce =
dynamic_cast<DialogCompletionEvent*>(event);<br>
800 if (dce == nullptr)<br>
801 return;<br>
<br>
<u>the assembler from -S option</u><br>
<br>
.text<br>
.globl _ZN21StandardSettingDialog11customEventEP6QEvent //
-- Begin function _ZN21StandardSettingDialog11customEventEP6QEvent<br>
.p2align 2<br>
.type
_ZN21StandardSettingDialog11customEventEP6QEvent,@function<br>
_ZN21StandardSettingDialog11customEventEP6QEvent: //
@_ZN21StandardSettingDialog11customEventEP6QEvent<br>
.Lfunc_begin167:<br>
.loc 68 796 0 is_stmt 1 //
standardsettings.cpp:796:0<br>
.cfi_startproc<br>
.cfi_personality 156, DW.ref.__gxx_personality_v0<br>
.cfi_lsda 28, .Lexception51<br>
// %bb.0:<br>
sub sp, sp, #192 // =192<br>
str x30, [sp, #176] // 8-byte Folded Spill<br>
.cfi_def_cfa_offset 192<br>
.cfi_offset w30, -16<br>
mrs x8, TPIDR_EL0<br>
ldr x8, [x8, #40]<br>
str x8, [sp, #168]<br>
str x0, [sp, #136]<br>
str x1, [sp, #128]<br>
ldr x8, [sp, #136]<br>
.Ltmp2139:<br>
.loc 68 797 9 prologue_end //
standardsettings.cpp:797:9<br>
ldr x0, [sp, #128]<br>
str x8, [sp, #72] // 8-byte Folded Spill<br>
.loc 68 797 16 is_stmt 0 //
standardsettings.cpp:797:16<br>
bl _ZNK6QEvent4typeEv<br>
.loc 68 797 26 //
standardsettings.cpp:797:26<br>
adrp x8, :got:_ZN21DialogCompletionEvent10kEventTypeE<br>
ldr x8, [x8,
:got_lo12:_ZN21DialogCompletionEvent10kEventTypeE]<br>
ldr w9, [x8]<br>
.Ltmp2140:<br>
.loc 68 797 9 //
standardsettings.cpp:797:9<br>
subs w9, w0, w9<br>
b.ne .LBB167_42<br>
b .LBB167_1<br>
.LBB167_1:<br>
.Ltmp2141:<br>
.loc 68 799 57 is_stmt 1 //
standardsettings.cpp:799:57<br>
ldr x8, [sp, #128]<br>
mov x0, x8<br>
str x0, [sp, #64] // 8-byte Folded Spill<br>
.loc 68 799 20 is_stmt 0 //
standardsettings.cpp:799:20<br>
cbz x8, .LBB167_3<br>
b .LBB167_2<br>
.LBB167_2:<br>
adrp x1, :got:_ZTI6QEvent<br>
ldr x1, [x1, :got_lo12:_ZTI6QEvent]<br>
adrp x2, :got:_ZTI21DialogCompletionEvent<br>
ldr x2, [x2, :got_lo12:_ZTI21DialogCompletionEvent]<br>
mov x0, xzr<br>
ldr x3, [sp, #64] // 8-byte Folded Reload<br>
str x0, [sp, #56] // 8-byte Folded Spill<br>
mov x0, x3<br>
ldr x3, [sp, #56] // 8-byte Folded Reload<br>
bl __dynamic_cast<br>
str x0, [sp, #48] // 8-byte Folded Spill<br>
b .LBB167_4<br>
.LBB167_3:<br>
.loc 68 0 20 // standardsettings.cpp:0:20<br>
mov x0, xzr<br>
str x0, [sp, #48] // 8-byte Folded Spill<br>
.loc 68 799 20 //
standardsettings.cpp:799:20<br>
b .LBB167_4<br>
.LBB167_4:<br>
.loc 68 0 20 // standardsettings.cpp:0:20<br>
ldr x8, [sp, #48] // 8-byte Folded Reload<br>
.loc 68 799 14 //
standardsettings.cpp:799:14<br>
str x8, [sp, #120]<br>
.Ltmp2142:<br>
.loc 68 800 13 is_stmt 1 //
standardsettings.cpp:800:13<br>
ldr x8, [sp, #120]<br>
.Ltmp2143:<br>
.loc 68 800 13 is_stmt 0 //
standardsettings.cpp:800:13<br>
cbnz x8, .LBB167_6<br>
b .LBB167_5<br>
.LBB167_5:<br>
.Ltmp2144:<br>
<br>
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