https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89491
Bug ID: 89491
Summary: Inline jump tables
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: david.bolvansky at gmail dot com
Target Milestone: ---
int square(int x) {
return x*x;
}
int add(int x) {
return x + x;
}
typedef int (*p) (int);
p arr[4] = {square, add};
int test(int x) {
int res = arr[1](x);
return res;
}
Expected:
test(int):
lea eax, [rdi+rdi]
ret
Currently:
test(int):
jmp [QWORD PTR arr[rip+8]]
------------
If the index to the jump table isn't a constant, should not be better to expand
"if else" chain like:
if (x==1) arr[1](x);
else if (x==2) arr[2](x);
..and then take an opportunity to inline functions?
