Hi,
Gentle ping:
https://gcc.gnu.org/pipermail/gcc-patches/2022-July/598980.html
BR,
Jeff(Jiufu)
Jiufu Guo <guoji...@linux.ibm.com> writes:
> Hi,
>
> As the issue in PR106460, a rtx 'high:DI (symbol_ref:DI ("var_48")' is tried
> to store into constant pool. But actually, it indicates partial address,
> which to be forced to constant memory.
>
> In function rs6000_cannot_force_const_mem, we already return true for
> "HIGH with UNSPEC" rtx. For this function if GET_CODE (X) is HIGH, the "X"
> represents the high part of a symbol ref, this function would also return
> true. Below are some examples:
> (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.
>
> PR target/106460
>
> gcc/ChangeLog:
>
> * config/rs6000/rs6000.cc (rs6000_cannot_force_const_mem): Return true
> for HIGH code rtx.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/powerpc/pr106460.c: New test.
>
> ---
> gcc/config/rs6000/rs6000.cc | 7 +++++--
> gcc/testsuite/gcc.target/powerpc/pr106460.c | 11 +++++++++++
> 2 files changed, 16 insertions(+), 2 deletions(-)
> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr106460.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)
> + /* If GET_CODE (x) is HIGH, the 'X' represets the high part of a
> symbol_ref.
> + It indicates partial address, which can not be put into a constant
> pool.
> + e.g. (high:DI (unspec:DI [(symbol_ref/u:DI ("*.LC0")..)
> + (high:DI (symbol_ref:DI ("var")..)). */
> + 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/pr106460.c
> b/gcc/testsuite/gcc.target/powerpc/pr106460.c
> new file mode 100644
> index 00000000000..ed7a994827b
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/powerpc/pr106460.c
> @@ -0,0 +1,11 @@
> +/* { 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;
> +}
> +
