[Bug target/55212] [SH] Switch to LRA

[kkojima at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=55212

--- Comment #148 from Kazumoto Kojima <kkojima at gcc dot gnu.org> ---
Created attachment 58882
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=58882&action=edit
a testcase for c++ problem with the patch 58831 both for -mlra and -mno-lra

sh.cc:sh_output_mi_thunk generates the insn

(parallel [
            (call (mem:SI (symbol_ref:SI ("*.LTHUNK8") [flags 0x3]
<function_decl 0x7df4cdb83c00 *.LTHUNK8>) [0  S4 A32])
                (const_int 0 [0]))
            (use (reg:SI 154 fpscr0))
            (clobber (reg:SI 3 r3))
            (return)
        ])

for thunk. The patch 58831 made it unrecognizable.   A fix will be to use R3
instead of R1 as the scratch in the sibcall_pcrel pattern.
Clearly it will break -fcall_saved-reg or -ffixed-reg cases commented in
sh_output_mi_thunk() a bit.  I guess that it's too rare to be considered.