Andrew Pinski <quic_apin...@quicinc.com> writes:
> After r15-6660-g45d306a835cb3f865, in some cases
> DFP constants would cause an ICE. This is due to
> do a mismatch of a few things. The predicate of the move
> uses aarch64_valid_fp_move to say if the constant is valid or not.
> But after reload/LRA when can_create_pseudo_p returns false;
> aarch64_valid_fp_move
> would return false for constants that were valid for the constraints
> of the instruction. A strictor predicate compared to the constraint is wrong.
> In this case `Uvi` is the constraint while aarch64_valid_fp_move allows it
> via aarch64_can_const_movi_rtx_p for !DECIMAL_FLOAT_MODE_P, there is no such
> check
> for DECIMAL_FLOAT_MODE_P.
>
> The fix is to remove the check !DECIMAL_FLOAT_MODE_P in aarch64_valid_fp_move
> and in the define_expand. As now the predicate allows a superset of what is
> allowed
> by the constraints.
>
> Built and tested on aarch64-linux-gnu with no regressions.
>
> PR target/119131
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.cc (aarch64_valid_fp_move): Remove check
> for !DECIMAL_FLOAT_MODE_P.
> * config/aarch64/aarch64.md (mov<mode>): Likewise.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.dg/torture/pr119131-1.c: New test.
>
> Signed-off-by: Andrew Pinski <quic_apin...@quicinc.com>
> ---
> gcc/config/aarch64/aarch64.cc | 17 +++++--------
> gcc/config/aarch64/aarch64.md | 3 +--
> gcc/testsuite/gcc.dg/torture/pr119131-1.c | 31 +++++++++++++++++++++++
> 3 files changed, 39 insertions(+), 12 deletions(-)
> create mode 100644 gcc/testsuite/gcc.dg/torture/pr119131-1.c
>
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index 36b65df50c5..ecd005d32d8 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -11328,17 +11328,14 @@ aarch64_valid_fp_move (rtx dst, rtx src,
> machine_mode mode)
> if (MEM_P (src))
> return true;
>
> - if (!DECIMAL_FLOAT_MODE_P (mode))
> - {
> - if (aarch64_can_const_movi_rtx_p (src, mode)
> - || aarch64_float_const_representable_p (src)
> - || aarch64_float_const_zero_rtx_p (src))
> - return true;
> + if (aarch64_can_const_movi_rtx_p (src, mode)
> + || aarch64_float_const_representable_p (src)
> + || aarch64_float_const_zero_rtx_p (src))
> + return true;
Don't we then also need to add a !DECIMAL_FLOAT_MODE_P (mode)
check to aarch64_float_const_representable_p?
Otherwise it looks good. Thanks for fixing this.
Richard
>
> - /* Block FP immediates which are split during expand. */
> - if (aarch64_float_const_rtx_p (src))
> - return false;
> - }
> + /* Block FP immediates which are split during expand. */
> + if (aarch64_float_const_rtx_p (src))
> + return false;
>
> return can_create_pseudo_p ();
> }
> diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
> index 03188a64ab1..031e621c98a 100644
> --- a/gcc/config/aarch64/aarch64.md
> +++ b/gcc/config/aarch64/aarch64.md
> @@ -1762,8 +1762,7 @@ (define_expand "mov<mode>"
> && aarch64_float_const_zero_rtx_p (operands[1])))
> operands[1] = force_reg (<MODE>mode, operands[1]);
>
> - if (!DECIMAL_FLOAT_MODE_P (<MODE>mode)
> - && GET_CODE (operands[1]) == CONST_DOUBLE
> + if (GET_CODE (operands[1]) == CONST_DOUBLE
> && can_create_pseudo_p ()
> && !aarch64_can_const_movi_rtx_p (operands[1], <MODE>mode)
> && !aarch64_float_const_representable_p (operands[1])
> diff --git a/gcc/testsuite/gcc.dg/torture/pr119131-1.c
> b/gcc/testsuite/gcc.dg/torture/pr119131-1.c
> new file mode 100644
> index 00000000000..c62f702f98c
> --- /dev/null
> +++ b/gcc/testsuite/gcc.dg/torture/pr119131-1.c
> @@ -0,0 +1,31 @@
> +/* { dg-do compile } */
> +/* { dg-require-effective-target dfp } */
> +/* PR target/119131 */
> +
> +typedef __attribute__((__vector_size__ (64))) char C;
> +typedef __attribute__((__vector_size__ (64))) _Decimal32 D;
> +int a, b;
> +_Decimal32 f;
> +C e;
> +C c;
> +
> +void
> +foo (D d)
> +{
> + d -= *(_Decimal32 *) __builtin_memset (&f, 0, 4);
> + b += a;
> + if (a)
> + b /= 0; /* { dg-warning "division by zero" } */
> + c = (C) d + e;
> +}
> +
> +void
> +foo1 (D d)
> +{
> + __builtin_memset (&f, 0, 4);
> + d -= *(_Decimal32 *)&f;
> + b += a;
> + if (a)
> + b /= 0;/* { dg-warning "division by zero" } */
> + c = (C) d + e;
> +}
