Re: [PATCH v2] bpf: correct bpf_print_operand for floats [PR108293]

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

> Hi Jose,
>
> As we discussed on IRC, since we don't currently define
> TARGET_SUPPORTS_WIDE_INT it is safer to keep the handling for VOIDmode
> CONST_DOUBLEs. My current understanding is that it may be needed if the
> host is a 32-bit platform.
>
> I also added a gcc_unreachable () as you pointed out. V2 below.
> Tested with bpf-unknown-none on x86_64 host, no known regressions.
>
> WDYT?

OK for master.
Thanks!

>
> Thanks,
> David
>
> ---
>
> [Changes from v1:
>  - Keep handling for VOIDmode CONST_DOUBLE, just in case.
>  - Add a gcc_unreachable () if `op` is none of VOIDmode, SFmode,
>    nor DFmode. ]
>
> The existing logic in bpf_print_operand was only correct for integral
> CONST_DOUBLEs, and emitted garbage for floating point modes. Fix it so
> floating point mode operands are correctly handled.
>
> 	PR target/108293
>
> gcc/
>
> 	* config/bpf/bpf.cc (bpf_print_operand): Correct handling for
> 	floating point modes.
>
> gcc/testsuite/
>
> 	* gcc.target/bpf/double-1.c: New test.
> 	* gcc.target/bpf/double-2.c: New test.
> 	* gcc.target/bpf/float-1.c: New test.
> ---
>  gcc/config/bpf/bpf.cc                   | 34 ++++++++++++++++++++-----
>  gcc/testsuite/gcc.target/bpf/double-1.c | 12 +++++++++
>  gcc/testsuite/gcc.target/bpf/double-2.c | 12 +++++++++
>  gcc/testsuite/gcc.target/bpf/float-1.c  | 12 +++++++++
>  4 files changed, 64 insertions(+), 6 deletions(-)
>  create mode 100644 gcc/testsuite/gcc.target/bpf/double-1.c
>  create mode 100644 gcc/testsuite/gcc.target/bpf/double-2.c
>  create mode 100644 gcc/testsuite/gcc.target/bpf/float-1.c
>
> diff --git a/gcc/config/bpf/bpf.cc b/gcc/config/bpf/bpf.cc
> index 2aeaeaf309b..576a1fe8eab 100644
> --- a/gcc/config/bpf/bpf.cc
> +++ b/gcc/config/bpf/bpf.cc
> @@ -880,13 +880,35 @@ bpf_print_operand (FILE *file, rtx op, int code ATTRIBUTE_UNUSED)
>        output_address (GET_MODE (op), XEXP (op, 0));
>        break;
>      case CONST_DOUBLE:
> -      if (CONST_DOUBLE_HIGH (op))
> -	fprintf (file, HOST_WIDE_INT_PRINT_DOUBLE_HEX,
> -		 CONST_DOUBLE_HIGH (op), CONST_DOUBLE_LOW (op));
> -      else if (CONST_DOUBLE_LOW (op) < 0)
> -	fprintf (file, HOST_WIDE_INT_PRINT_HEX, CONST_DOUBLE_LOW (op));
> +      if (GET_MODE (op) == VOIDmode)
> +	{
> +	  if (CONST_DOUBLE_HIGH (op))
> +	    fprintf (file, HOST_WIDE_INT_PRINT_DOUBLE_HEX,
> +		     CONST_DOUBLE_HIGH (op), CONST_DOUBLE_LOW (op));
> +	  else if (CONST_DOUBLE_LOW (op) < 0)
> +	    fprintf (file, HOST_WIDE_INT_PRINT_HEX, CONST_DOUBLE_LOW (op));
> +	  else
> +	    fprintf (file, HOST_WIDE_INT_PRINT_DEC, CONST_DOUBLE_LOW (op));
> +	}
>        else
> -	fprintf (file, HOST_WIDE_INT_PRINT_DEC, CONST_DOUBLE_LOW (op));
> +	{
> +	  long vals[2];
> +	  real_to_target (vals, CONST_DOUBLE_REAL_VALUE (op), GET_MODE (op));
> +	  vals[0] &= 0xffffffff;
> +	  vals[1] &= 0xffffffff;
> +	  if (GET_MODE (op) == SFmode)
> +	    fprintf (file, "0x%08lx", vals[0]);
> +	  else if (GET_MODE (op) == DFmode)
> +	    {
> +	      /* Note: real_to_target puts vals in target word order.  */
> +	      if (WORDS_BIG_ENDIAN)
> +		fprintf (file, "0x%08lx%08lx", vals[0], vals[1]);
> +	      else
> +		fprintf (file, "0x%08lx%08lx", vals[1], vals[0]);
> +	    }
> +	  else
> +	    gcc_unreachable ();
> +	}
>        break;
>      default:
>        output_addr_const (file, op);
> diff --git a/gcc/testsuite/gcc.target/bpf/double-1.c b/gcc/testsuite/gcc.target/bpf/double-1.c
> new file mode 100644
> index 00000000000..200f1bd18f8
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/double-1.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mlittle-endian" } */
> +
> +double f;
> +double a() { f = 1.0; return 1.0; }
> +double b() { f = 2.0; return 2.0; }
> +double c() { f = 2.0; return 3.0; }
> +double d() { f = 3.0; return 3.0; }
> +
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x3ff0000000000000" 2 } } */
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x4000000000000000" 3 } } */
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x4008000000000000" 3 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/double-2.c b/gcc/testsuite/gcc.target/bpf/double-2.c
> new file mode 100644
> index 00000000000..d04ddd0c575
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/double-2.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mbig-endian" } */
> +
> +double f;
> +double a() { f = 1.0; return 1.0; }
> +double b() { f = 2.0; return 2.0; }
> +double c() { f = 2.0; return 3.0; }
> +double d() { f = 3.0; return 3.0; }
> +
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x3ff0000000000000" 2 } } */
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x4000000000000000" 3 } } */
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x4008000000000000" 3 } } */
> diff --git a/gcc/testsuite/gcc.target/bpf/float-1.c b/gcc/testsuite/gcc.target/bpf/float-1.c
> new file mode 100644
> index 00000000000..05ed7bb651d
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/bpf/float-1.c
> @@ -0,0 +1,12 @@
> +/* { dg-do compile } */
> +/* { dg-options "-mlittle-endian" } */
> +
> +float f;
> +float a() { f = 1.0; return 1.0; }
> +float b() { f = 2.0; return 2.0; }
> +float c() { f = 2.0; return 3.0; }
> +float d() { f = 3.0; return 3.0; }
> +
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x3f800000" 2 } } */
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x40000000" 3 } } */
> +/* { dg-final { scan-assembler-times "lddw\t%r.,0x40400000" 3 } } */