Make get_value_for_expr check for INTEGER_CSTs

Message ID mptr24e14d1.fsf@arm.com
State New
Headers show
Series
  • Make get_value_for_expr check for INTEGER_CSTs
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Commit Message

Richard Sandiford Sept. 18, 2019, 6:54 a.m.
CONSTANT lattice values are symbolic constants rather than
compile-time constants, so among other things can be POLY_INT_CSTs.
This patch fixes a case in which we assumed all CONSTANTs were either
ADDR_EXPRs or INTEGER_CSTs.

This is tested by later SVE patches.

Tested on aarch64-linux-gnu with SVE (with and without follow-on
patches) and x86_64-linux-gnu.  OK to install?

Richard


2019-09-18  Richard Sandiford  <richard.sandiford@arm.com>

gcc/
	* tree-ssa-ccp.c (get_value_for_expr): Check whether CONSTANTs
	are INTEGER_CSTs.

Comments

Richard Biener Sept. 18, 2019, 9 a.m. | #1
On Wed, Sep 18, 2019 at 8:54 AM Richard Sandiford
<richard.sandiford@arm.com> wrote:
>

> CONSTANT lattice values are symbolic constants rather than

> compile-time constants, so among other things can be POLY_INT_CSTs.

> This patch fixes a case in which we assumed all CONSTANTs were either

> ADDR_EXPRs or INTEGER_CSTs.

>

> This is tested by later SVE patches.

>

> Tested on aarch64-linux-gnu with SVE (with and without follow-on

> patches) and x86_64-linux-gnu.  OK to install?


OK.

Richard.

> Richard

>

>

> 2019-09-18  Richard Sandiford  <richard.sandiford@arm.com>

>

> gcc/

>         * tree-ssa-ccp.c (get_value_for_expr): Check whether CONSTANTs

>         are INTEGER_CSTs.

>

> Index: gcc/tree-ssa-ccp.c

> ===================================================================

> --- gcc/tree-ssa-ccp.c  2019-08-21 14:58:05.999057076 +0100

> +++ gcc/tree-ssa-ccp.c  2019-09-18 07:53:36.930481545 +0100

> @@ -615,9 +615,17 @@ get_value_for_expr (tree expr, bool for_

>           val.mask = -1;

>         }

>        if (for_bits_p

> -         && val.lattice_val == CONSTANT

> -         && TREE_CODE (val.value) == ADDR_EXPR)

> -       val = get_value_from_alignment (val.value);

> +         && val.lattice_val == CONSTANT)

> +       {

> +         if (TREE_CODE (val.value) == ADDR_EXPR)

> +           val = get_value_from_alignment (val.value);

> +         else if (TREE_CODE (val.value) != INTEGER_CST)

> +           {

> +             val.lattice_val = VARYING;

> +             val.value = NULL_TREE;

> +             val.mask = -1;

> +           }

> +       }

>        /* Fall back to a copy value.  */

>        if (!for_bits_p

>           && val.lattice_val == VARYING

Patch

Index: gcc/tree-ssa-ccp.c
===================================================================
--- gcc/tree-ssa-ccp.c	2019-08-21 14:58:05.999057076 +0100
+++ gcc/tree-ssa-ccp.c	2019-09-18 07:53:36.930481545 +0100
@@ -615,9 +615,17 @@  get_value_for_expr (tree expr, bool for_
 	  val.mask = -1;
 	}
       if (for_bits_p
-	  && val.lattice_val == CONSTANT
-	  && TREE_CODE (val.value) == ADDR_EXPR)
-	val = get_value_from_alignment (val.value);
+	  && val.lattice_val == CONSTANT)
+	{
+	  if (TREE_CODE (val.value) == ADDR_EXPR)
+	    val = get_value_from_alignment (val.value);
+	  else if (TREE_CODE (val.value) != INTEGER_CST)
+	    {
+	      val.lattice_val = VARYING;
+	      val.value = NULL_TREE;
+	      val.mask = -1;
+	    }
+	}
       /* Fall back to a copy value.  */
       if (!for_bits_p
 	  && val.lattice_val == VARYING