There is a missing opportunity for optimization.
int f(void);
void test(int x) {
if (x & 1 ? x == 0 : x > 0) f();
}
This is gcc-4.1.0-0.20051206 with some patches by PLD Linux
Distribution. gcc -S -O2 -fomit-frame-pointer generates the
following code:
test:
movl 4(%esp), %eax
testb $1, %al
je .L2
testl %eax, %eax
sete %al
testb %al, %al
jne .L9
.L7:
rep ; ret
.p2align 4,,7
.L2:
testl %eax, %eax
setg %al
testb %al, %al
je .L7
.L9:
jmp f
It makes little sense to materialize the boolean result of the
condition in %al, and then to test %al for 0. I would expect
direct conditional jumps to branches of the outer if.
--
__("< Marcin Kowalczyk
\__/ [EMAIL PROTECTED]
^^ http://qrnik.knm.org.pl/~qrczak/
