http://gcc.gnu.org/bugzilla/show_bug.cgi?id=56661
Bug #: 56661
Summary: [4.8 regression] Incorrect code with -O1 -ftree-pre
Classification: Unclassified
Product: gcc
Version: 4.8.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: manisan...@gmail.com
Using gcc version 4.8.0 20130316 (Red Hat 4.8.0-0.17)
----------------- main.c -----------------
typedef long unsigned int size_t;
extern int printf (const char *__restrict __format, ...);
extern void *malloc (size_t __size) __attribute__ ((__nothrow__ , __leaf__))
__attribute__ ((__malloc__));
void setb(int* b);
void foo(int x){
if(x == 0){
int* b = malloc(3*sizeof(int));
while(b[0]);
}else if(x == 1){
int i, j;
int* b = malloc(3*sizeof(int));
for(i = 0; i < 2; i++){
setb(b);
for(j = 0; j < 3; ++j){
printf("%d ", b[j]);
}
printf("\nb[0] = %d\n", b[0]);
}
}
}
extern int g_x;
int main(){
foo(g_x);
return 0;
}
----------------- stuff.c -----------------
void setb(int* b){
b[0] = b[1] = b[2] = 1;
}
int g_x = 1;
-------------------------------------------
$ gcc -O1 -ftree-pre -o test main.c stuff.c
$ ./test
1 1 1
b[0] = 0
1 1 1
b[0] = 0
Works with gcc version 4.7.2 20121109 (Red Hat 4.7.2-8)
