Hi Jeff,
on 2022/7/19 22:30, Jiufu Guo wrote:
> Hi,
>
> In patch https://gcc.gnu.org/pipermail/gcc-patches/2022-July/597712.html,
> test case was not added. After more check, a testcase is added for it.
>
Good to see that you constructed one actual test case, nice! :)
> The high part of the symbol address is invalid for the constant pool.
> In function rs6000_cannot_force_const_mem, we already return true for
> "HIGH with UNSPEC" rtx. Below are some examples also indicate the high
> part of a symbol_ref:
> (high:DI (const:DI (plus:DI (symbol_ref:DI ("xx") (const_int 12 [0xc])))))
> (high:DI (symbol_ref:DI ("var_1")..)))
>
> This patch updates rs6000_cannot_force_const_mem to return true for
> rtx with HIGH code.
>
> Bootstrapped and regtested on ppc64le and ppc64.
> Is it ok for trunk?
I think this patch is OK with some nits below tweaked.
>
> BR,
> Jeff(Jiufu)
>
>
> gcc/ChangeLog:
>
> * config/rs6000/rs6000.cc (rs6000_cannot_force_const_mem):
> Return true for HIGH code rtx.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/powerpc/constpoolcheck.c: New test.
>
> ---
> gcc/config/rs6000/rs6000.cc | 7 +++++--
> gcc/testsuite/gcc.target/powerpc/constpoolcheck.c | 11 +++++++++++
> 2 files changed, 16 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
>
> diff --git a/gcc/config/rs6000/rs6000.cc b/gcc/config/rs6000/rs6000.cc
> index 0af2085adc0..d56832ebbfc 100644
> --- a/gcc/config/rs6000/rs6000.cc
> +++ b/gcc/config/rs6000/rs6000.cc
> @@ -9704,8 +9704,11 @@ rs6000_init_stack_protect_guard (void)
> static bool
> rs6000_cannot_force_const_mem (machine_mode mode ATTRIBUTE_UNUSED, rtx x)
> {
> - if (GET_CODE (x) == HIGH
> - && GET_CODE (XEXP (x, 0)) == UNSPEC)
> + /* High part of a symbol ref/address can not be put into constant pool.
> e.g.
Nit: two spaces after the period in "... pool.".
> + (high:DI (symbol_ref:DI ("var")..)) or
Nit: You have one "or" at the end of the above line, I think it's better to
keep the below line consistent by either removing the above " or" or adding
one "or" at the end of the below line.
> + (high:DI (unspec:DI [(symbol_ref/u:DI ("*.LC0")..)
> + (high:DI (const:DI (plus:DI (symbol_ref:DI ("xx")) (const_int 12)))).
> */
> + if (GET_CODE (x) == HIGH)
> return true;
>
> /* A TLS symbol in the TOC cannot contain a sum. */
> diff --git a/gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
> b/gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
> new file mode 100644
> index 00000000000..ed7a994827b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/constpoolcheck.c
Maybe it's good to name it to "const-pool-check.c" or "not-force-const-mem.c".
> @@ -0,0 +1,11 @@
> +/* { dg-do compile { target powerpc*-*-* } } */
Nit: this "dg-do" line isn't needed since all here are default.
BR,
Kewen
> +/* { dg-options "-O1 -mdejagnu-cpu=power10" } */
> +/* (high:DI (symbol_ref:DI ("var_48")..))) should not cause ICE. */
> +extern short var_48;
> +void
> +foo (double *r)
> +{
> + if (var_48)
> + *r = 1234.5678;
> +}
> +
