https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103784
Bug ID: 103784
Summary: suboptimal code for returning bool value on target ppc
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: guihaoc at gcc dot gnu.org
Target Milestone: ---
//test.c
#include <stdbool.h>
bool foo (int a, int b)
{
if (a > 2)
return false;
if (b < 10)
return true;
return true;
}
//assembly with trunk
ld 9,0(3)
cmpdi 0,9,0
add 10,9,4
beq 0,.L5
ldarx 8,0,3
cmpd 0,8,9
bne 0,.L4
stdcx. 10,0,3
bne 0,.L4
li 3,1
rldicl 3,3,0,63
blr
.p2align 4,,15
.L5:
li 3,0
rldicl 3,3,0,63
blr
//assembly with at13.0
subfic 3,3,2
srdi 3,3,63
xori 3,3,0x1
blr
The second branch and two zero extend are unnecessary. If it returns a integer,
the code seems good.
//test1.c
int foo (int a, int b)
{
if (a > 2)
return 0;
if (b < 10)
return 1;
return 1;
}
//assembly with trunk
li 9,1
cmpwi 0,3,2
isel 3,0,9,1
blr
