[PATCH] simplify-rtx: Fix up simplify_logical_relational_operation for vector IOR [PR101008]

Richard Biener rguenther@suse.de
Fri Jun 11 10:49:46 GMT 2021


On Fri, 11 Jun 2021, Jakub Jelinek wrote:

> Hi!
> 
> simplify_relational_operation callees typically return just const0_rtx
> or const_true_rtx and then simplify_relational_operation attempts to fix
> that up if the comparison result has vector mode, or floating mode,
> or punt if it has scalar mode and vector mode operands (it doesn't know how
> exactly to deal with the scalar masks).
> But, simplify_logical_relational_operation has a special case, where
> it attempts to fold (x < y) | (x >= y) etc. and if it determines it is
> always true, it just returns const_true_rtx, without doing the dances that
> simplify_relational_operation does.
> That results in an ICE on the following testcase, where such folding happens
> during expansion (of debug stmts into DEBUG_INSNs) and we ICE because
> all of sudden a VOIDmode rtx appears where it expects a vector (V4SImode)
> rtx.
> 
> The following patch fixes that by moving the adjustement into a separate
> helper routine and using it from both simplify_relational_operation and
> simplify_logical_relational_operation.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK.

Thanks,
Richard.

> 2021-06-11  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR rtl-optimization/101008
> 	* simplify-rtx.c (relational_result): New function.
> 	(simplify_logical_relational_operation,
> 	simplify_relational_operation): Use it.
> 
> 	* gcc.dg/pr101008.c: New test.
> 
> --- gcc/simplify-rtx.c.jj	2021-05-04 21:02:24.000000000 +0200
> +++ gcc/simplify-rtx.c	2021-06-10 13:56:48.946628822 +0200
> @@ -2294,6 +2294,53 @@ comparison_code_valid_for_mode (enum rtx
>  	gcc_unreachable ();
>      }
>  }
> +
> +/* Canonicalize RES, a scalar const0_rtx/const_true_rtx to the right
> +   false/true value of comparison with MODE where comparison operands
> +   have CMP_MODE.  */
> +
> +static rtx
> +relational_result (machine_mode mode, machine_mode cmp_mode, rtx res)
> +{
> +  if (SCALAR_FLOAT_MODE_P (mode))
> +    {
> +      if (res == const0_rtx)
> +        return CONST0_RTX (mode);
> +#ifdef FLOAT_STORE_FLAG_VALUE
> +      REAL_VALUE_TYPE val = FLOAT_STORE_FLAG_VALUE (mode);
> +      return const_double_from_real_value (val, mode);
> +#else
> +      return NULL_RTX;
> +#endif
> +    }
> +  if (VECTOR_MODE_P (mode))
> +    {
> +      if (res == const0_rtx)
> +	return CONST0_RTX (mode);
> +#ifdef VECTOR_STORE_FLAG_VALUE
> +      rtx val = VECTOR_STORE_FLAG_VALUE (mode);
> +      if (val == NULL_RTX)
> +	return NULL_RTX;
> +      if (val == const1_rtx)
> +	return CONST1_RTX (mode);
> +
> +      return gen_const_vec_duplicate (mode, val);
> +#else
> +      return NULL_RTX;
> +#endif
> +    }
> +  /* For vector comparison with scalar int result, it is unknown
> +     if the target means here a comparison into an integral bitmask,
> +     or comparison where all comparisons true mean const_true_rtx
> +     whole result, or where any comparisons true mean const_true_rtx
> +     whole result.  For const0_rtx all the cases are the same.  */
> +  if (VECTOR_MODE_P (cmp_mode)
> +      && SCALAR_INT_MODE_P (mode)
> +      && res == const_true_rtx)
> +    return NULL_RTX;
> +
> +  return res;
> +}
>  				       
>  /* Simplify a logical operation CODE with result mode MODE, operating on OP0
>     and OP1, which should be both relational operations.  Return 0 if no such
> @@ -2329,7 +2376,7 @@ simplify_context::simplify_logical_relat
>    int mask = mask0 | mask1;
>  
>    if (mask == 15)
> -    return const_true_rtx;
> +    return relational_result (mode, GET_MODE (op0), const_true_rtx);
>  
>    code = mask_to_comparison (mask);
>  
> @@ -5315,51 +5362,7 @@ simplify_context::simplify_relational_op
>  
>    tem = simplify_const_relational_operation (code, cmp_mode, op0, op1);
>    if (tem)
> -    {
> -      if (SCALAR_FLOAT_MODE_P (mode))
> -	{
> -          if (tem == const0_rtx)
> -            return CONST0_RTX (mode);
> -#ifdef FLOAT_STORE_FLAG_VALUE
> -	  {
> -	    REAL_VALUE_TYPE val;
> -	    val = FLOAT_STORE_FLAG_VALUE (mode);
> -	    return const_double_from_real_value (val, mode);
> -	  }
> -#else
> -	  return NULL_RTX;
> -#endif
> -	}
> -      if (VECTOR_MODE_P (mode))
> -	{
> -	  if (tem == const0_rtx)
> -	    return CONST0_RTX (mode);
> -#ifdef VECTOR_STORE_FLAG_VALUE
> -	  {
> -	    rtx val = VECTOR_STORE_FLAG_VALUE (mode);
> -	    if (val == NULL_RTX)
> -	      return NULL_RTX;
> -	    if (val == const1_rtx)
> -	      return CONST1_RTX (mode);
> -
> -	    return gen_const_vec_duplicate (mode, val);
> -	  }
> -#else
> -	  return NULL_RTX;
> -#endif
> -	}
> -      /* For vector comparison with scalar int result, it is unknown
> -	 if the target means here a comparison into an integral bitmask,
> -	 or comparison where all comparisons true mean const_true_rtx
> -	 whole result, or where any comparisons true mean const_true_rtx
> -	 whole result.  For const0_rtx all the cases are the same.  */
> -      if (VECTOR_MODE_P (cmp_mode)
> -	  && SCALAR_INT_MODE_P (mode)
> -	  && tem == const_true_rtx)
> -	return NULL_RTX;
> -
> -      return tem;
> -    }
> +    return relational_result (mode, cmp_mode, tem);
>  
>    /* For the following tests, ensure const0_rtx is op1.  */
>    if (swap_commutative_operands_p (op0, op1)
> --- gcc/testsuite/gcc.dg/pr101008.c.jj	2021-06-10 14:20:02.230559294 +0200
> +++ gcc/testsuite/gcc.dg/pr101008.c	2021-06-10 14:19:36.518911260 +0200
> @@ -0,0 +1,18 @@
> +/* PR rtl-optimization/101008 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -g" } */
> +
> +typedef unsigned __attribute__((__vector_size__(32))) U;
> +typedef unsigned __attribute__((__vector_size__(16))) V;
> +
> +int c, r;
> +
> +V v;
> +
> +void
> +foo(void)
> +{
> +  U u = __builtin_shufflevector (v, (V)(v != c) | (V)(c == v),
> +				 4, 3, 5, 5, 1, 2, 3, 0);
> +  r = ((union { U a; int b; }) u).b;
> +}
> 
> 	Jakub
> 
> 

-- 
Richard Biener <rguenther@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imendörffer; HRB 36809 (AG Nuernberg)


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