https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120675
Bug ID: 120675
Summary: Missed loop invariant code elimination from loop
Product: gcc
Version: 16.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: vekumar at gcc dot gnu.org
Target Milestone: ---
For the below case GCC does not remove store of 3 from the loop.
void test_licm(int * restrict a, int * restrict b, int n) {
for (int i=0;i<n;i++) {
b[0] = 3;
a[i] = a[i] + b[i];
}
}
-O3
Assembly
--Snip--
.L3:
movl $3, (%rsi)
movl (%rsi,%rax), %ecx
addl %ecx, (%rdi,%rax)
addq $4, %rax
cmpq %rax, %rdx
jne .L3
--Snip--
ref: https://godbolt.org/z/rbhz9z6r1
