https://gcc.gnu.org/bugzilla/show_bug.cgi?id=114528
Bug ID: 114528
Summary: (0xFFFFFFFF0001FFFFULL - 0x00123000) constant forming
could be done in 2 instructions
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Target: aarch64
Take:
```
long long f()
{
return 0xFFFFFFFF0001FFFF;// - 0x00123000;
}
long long g(long long a)
{
return a - 0x00123000;
}
long long x()
{
return 0xFFFFFFFF0001FFFF - 0x00123000;
}
long long x1()
{
return g(f());
}
```
As you can see x and x1 produces 3 instructions forming the constant but GCC
should be able to do it in 2 as shown via `g` and `f` are one instruction each.
Noticed from reading the LLVM issue
https://github.com/llvm/llvm-project/issues/87028 .
