Re: [PATCH] bpf: fix pseudoc w regs for small modes [PR111029]

["Jose E. Marchesi" <jose.marchesi@oracle.com>]

Hello David.
Thanks for the patch.

OK.

> In the BPF pseudo-c assembly dialect, registers treated as 32-bits
> rather than the full 64 in various instructions ought to be printed as
> "wN" rather than "rN".  But bpf_print_register () was only doing this
> for specifically SImode registers, meaning smaller modes were printed
> incorrectly.
>
> This caused assembler errors like:
>
>   Error: unrecognized instruction `w2 =(s8)r1'
>
> for a 32-bit sign-extending register move instruction, where the source
> register is used in QImode.
>
> Fix bpf_print_register () to print the "w" version of register when
> specified by the template for any mode 32-bits or smaller.
>
> Tested on bpf-unknown-none.
>
> 	PR target/111029
>
> gcc/
> 	* config/bpf/bpf.cc (bpf_print_register): Print 'w' registers
> 	for any mode 32-bits or smaller, not just SImode.
>
> gcc/testsuite/
>
> 	* gcc.target/bpf/smov-2.c: New test.
> 	* gcc.target/bpf/smov-pseudoc-2.c: New test.
> ---
>  gcc/config/bpf/bpf.cc                         |  2 +-
>  gcc/testsuite/gcc.target/bpf/smov-2.c         | 15 +++++++++++++++
>  gcc/testsuite/gcc.target/bpf/smov-pseudoc-2.c | 15 +++++++++++++++
>  3 files changed, 31 insertions(+), 1 deletion(-)
>  create mode 100644 gcc/testsuite/gcc.target/bpf/smov-2.c
>  create mode 100644 gcc/testsuite/gcc.target/bpf/smov-pseudoc-2.c
>
> diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
> index 3516b79bce4..1d0abd7fbb3 100644
> --- a/gcc/config/bpf/bpf.cc
> +++ b/gcc/config/bpf/bpf.cc
> @@ -753,7 +753,7 @@ bpf_print_register (FILE *file, rtx op, int code)
>      fprintf (file, "%s", reg_names[REGNO (op)]);
>    else
>      {
> -      if (code == 'w' && GET_MODE (op) == SImode)
> +      if (code == 'w' && GET_MODE_SIZE (GET_MODE (op)) <= 4)
>  	{
>  	  if (REGNO (op) == BPF_FP)
>  	    fprintf (file, "w10");
> diff --git a/gcc/testsuite/gcc.target/bpf/smov-2.c b/gcc/testsuite/gcc.target/bpf/smov-2.c
> new file mode 100644
> index 00000000000..6f3516d2385
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/smov-2.c
> @@ -0,0 +1,15 @@
> +/* Check signed 32-bit mov instructions.  */
> +/* { dg-do compile } */
> +/* { dg-options "-mcpu=v4 -O2" } */
> +
> +int
> +foo (unsigned char a, unsigned short b)
> +{
> +  int x = (char) a;
> +  int y = (short) b;
> +
> +  return x + y;
> +}
> +
> +/* { dg-final { scan-assembler {movs32\t%r.,%r.,8\n} } } */
> +/* { dg-final { scan-assembler {movs32\t%r.,%r.,16\n} } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/smov-pseudoc-2.c b/gcc/testsuite/gcc.target/bpf/smov-pseudoc-2.c
> new file mode 100644
> index 00000000000..6af6cadf8df
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/smov-pseudoc-2.c
> @@ -0,0 +1,15 @@
> +/* Check signed 32-bit mov instructions (pseudo-C asm dialect).  */
> +/* { dg-do compile } */
> +/* { dg-options "-mcpu=v4 -O2 -masm=pseudoc" } */
> +
> +int
> +foo (unsigned char a, unsigned short b)
> +{
> +  int x = (char) a;
> +  int y = (short) b;
> +
> +  return x + y;
> +}
> +
> +/* { dg-final { scan-assembler {w. = \(s8\) w.\n} } } */
> +/* { dg-final { scan-assembler {w. = \(s16\) w.\n} } } */