Hi Suwa-san,
On Tue, Jan 17, 2023 at 8:23 PM Takayuki 'January June' Suwa
wrote:
> In the case of the CALL0 ABI, values that must be retained before and
> after function calls are placed in the callee-saved registers (A12
> through A15) and referenced later. However, it is often the case that
> the save and the reference are each only once and a simple register-
> register move (the frame pointer is needed to recover the stack pointer
> and must be excluded).
>
> e.g. in the following example, if there are no other occurrences of
> register A14:
>
> ;; before
> ; prologue {
> ...
> s32i.n a14, sp, 16
> ...
> ; } prologue
> ...
> mov.n a14, a6
> ...
> call0 foo
> ...
> mov.n a8, a14
> ...
> ; epilogue {
> ...
> l32i.n a14, sp, 16
> ...
> ; } epilogue
>
> It can be possible like this:
>
> ;; after
> ; prologue {
> ...
> (deleted)
> ...
> ; } prologue
> ...
> s32i.n a6, sp, 16
> ...
> call0 foo
> ...
> l32i.n a8, sp, 16
> ...
> ; epilogue {
> ...
> (deleted)
> ...
> ; } epilogue
>
> This patch introduces a new peephole2 pattern that implements the above.
>
> gcc/ChangeLog:
>
> * config/xtensa/xtensa.md: New peephole2 pattern that eliminates
> the use of callee-saved register that saves and restores only once
> for other register, by using its stack slot directly.
> ---
> gcc/config/xtensa/xtensa.md | 62 +
> 1 file changed, 62 insertions(+)
This change introduces a bunch of different test failures:
FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution, -O2
FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution, -O3 -g
FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution, -Os
FAIL: gcc.c-torture/execute/builtins/strpbrk.c execution, -O2 -flto
-fno-use-linker-plugin -flto-partition=none
FAIL: gcc.c-torture/execute/builtins/strstr-asm.c execution, -Os
FAIL: gcc.c-torture/execute/20001130-1.c -Os execution test
FAIL: gcc.c-torture/execute/20040311-1.c -O2 execution test
FAIL: gcc.c-torture/execute/20040311-1.c -O3 -g execution test
FAIL: gcc.c-torture/execute/20040311-1.c -O2 -flto
-fno-use-linker-plugin -flto-partition=none execution test
FAIL: gcc.c-torture/execute/20121108-1.c -O2 execution test
FAIL: gcc.c-torture/execute/20121108-1.c -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions execution
test
FAIL: gcc.c-torture/execute/20121108-1.c -O3 -g execution test
FAIL: gcc.c-torture/execute/20121108-1.c -Os execution test
FAIL: gcc.c-torture/execute/20121108-1.c -O2 -flto
-fno-use-linker-plugin -flto-partition=none execution test
FAIL: gcc.c-torture/execute/20121108-1.c -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects execution test
FAIL: gcc.c-torture/execute/20140622-1.c -O2 execution test
FAIL: gcc.c-torture/execute/20140622-1.c -O3 -g execution test
FAIL: gcc.c-torture/execute/20140622-1.c -O2 -flto
-fno-use-linker-plugin -flto-partition=none execution test
FAIL: gcc.c-torture/execute/20141022-1.c -O2 execution test
FAIL: gcc.c-torture/execute/20141022-1.c -O3 -fomit-frame-pointer
-funroll-loops -fpeel-loops -ftracer -finline-functions execution
test
FAIL: gcc.c-torture/execute/20141022-1.c -O3 -g execution test
FAIL: gcc.c-torture/execute/20141022-1.c -O2 -flto
-fno-use-linker-plugin -flto-partition=none execution test
FAIL: gcc.c-torture/execute/20141022-1.c -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects execution test
FAIL: gcc.c-torture/execute/20141107-1.c -O2 -flto
-fuse-linker-plugin -fno-fat-lto-objects execution test
FAIL: gcc.c-torture/execute/961213-1.c -Os execution test
FAIL: gcc.c-torture/execute/builtin-bitops-1.c -Os execution test
FAIL: gcc.c-torture/execute/cvt-1.c -O2 execution test
FAIL: gcc.c-torture/execute/cvt-1.c -O3 -g execution test
FAIL: gcc.c-torture/execute/cvt-1.c -Os execution test
FAIL: gcc.c-torture/execute/cvt-1.c -O2 -flto -fno-use-linker-plugin
-flto-partition=none execution test
FAIL: gcc.c-torture/execute/pr40747.c -O2 execution test
FAIL: gcc.c-torture/execute/pr40747.c -O3 -g execution test
FAIL: gcc.c-torture/execute/pr40747.c -O2 -flto
-fno-use-linker-plugin -flto-partition=none execution test
FAIL: gcc.c-torture/execute/pr60960.c -O2 execution test
FAIL: gcc.c-torture/execute/pr60960.c -O3 -g execution test
FAIL: gcc.c-torture/execute/pr60960.c -O2 -flto
-fno-use-linker-plugin -flto-partition=none execution test
FAIL: gcc.c-torture/execute/pr60960.c -O2 -flto -fuse-linker-plugin
-fno-fat-lto-objects execution test
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution, -O2
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution, -O3
-fomit-frame-pointer -funroll-loops -fpeel-loops -ftracer
-finline-functions
FAIL: gcc.c-torture/execute/ieee/fp-cmp-5.c execution, -O3 -g