Hi!
On Tue, May 05, 2026 at 04:45:39PM +0200, Peter Zijlstra wrote:
> On Tue, May 05, 2026 at 02:16:23PM +0530, Sathvika Vasireddy wrote:
> > switch (opcode) {
> > + case 16:
>
> Like case 18 below, this wants a comment describing which instruction
> this is; bclr ?
Yes. It is 19/16, b[c]lr (primary opcode 19, secondary opcode 16).
Where is it described what INSN_RETURN actually means for objtool? Not
in the header file :-(
For PowerPC, all three of b[c]lr[l], b[c]ctr[l], and b[c]tar[l] are
indirect jumps, to an address in a register. They do absolutely nothing
typically done in a function epilog, like "return" insns in some other
archs do. But the BH field ("branch hint") in the instruction helps
predict the control flow involving the insn as something in a call and
return pattern :-)
Segher
