Richard Biener <richard.guent...@gmail.com> writes:
> On Wed, Sep 20, 2017 at 2:06 PM, Richard Sandiford
> <richard.sandif...@linaro.org> wrote:
>> extract_range_from_binary_expr_1 had:
>>
>>       if (range_int_cst_p (&vr0)
>>           && range_int_cst_p (&vr1)
>>           && TYPE_OVERFLOW_WRAPS (expr_type))
>>         ...
>>       ...
>>       extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1);
>>
>> but extract_range_from_multiplicative_op_1 also requires range_int_cst_p.
>> I think we should bail out if either range isn't a constant.
>>
>> This might only be theoretical with current sources, but it's needed
>> once polynomial constants are added.
>>
>> Tested on aarch64-linux-gnu, x86_64-linux-gnu and powerpc64le-linus-gnu.
>> OK to install?
>
> extract_range_from_multiplicative_op_1 also allows anti-ranges but indeed
> requires INTEGER_CSTs.  Note it won't get anti-ranges because we handle
> this case by ranges_from_anti_range.
>
> Thus ok if you also remove the apparent anti-range handling from
> extract_range_from_multiplicative_op_1 (in the assert).

Thanks, here's what I committed after testing as before.

Richard


2017-09-22  Richard Sandiford  <richard.sandif...@linaro.org>
            Alan Hayward  <alan.hayw...@arm.com>
            David Sherwood  <david.sherw...@arm.com>

gcc/
        * tree-vrp.c (extract_range_from_multiplicative_op_1): Assert
        for VR_RANGE only; don't allow VR_ANTI_RANGE.
        (extract_range_from_binary_expr_1): Don't call
        extract_range_from_multiplicative_op_1 if !range_int_cst_p.

Index: gcc/tree-vrp.c
===================================================================
--- gcc/tree-vrp.c      2017-09-21 22:35:16.639777740 +0100
+++ gcc/tree-vrp.c      2017-09-22 17:46:45.207205032 +0100
@@ -1851,8 +1851,7 @@ extract_range_from_multiplicative_op_1 (
              || code == ROUND_DIV_EXPR
              || code == RSHIFT_EXPR
              || code == LSHIFT_EXPR);
-  gcc_assert ((vr0->type == VR_RANGE
-              || (code == MULT_EXPR && vr0->type == VR_ANTI_RANGE))
+  gcc_assert (vr0->type == VR_RANGE
              && vr0->type == vr1->type);
 
   rtype = vr0->type;
@@ -2462,9 +2461,14 @@ extract_range_from_binary_expr_1 (value_
       signop sign = TYPE_SIGN (expr_type);
       unsigned int prec = TYPE_PRECISION (expr_type);
 
-      if (range_int_cst_p (&vr0)
-         && range_int_cst_p (&vr1)
-         && TYPE_OVERFLOW_WRAPS (expr_type))
+      if (!range_int_cst_p (&vr0)
+         || !range_int_cst_p (&vr1))
+       {
+         set_value_range_to_varying (vr);
+         return;
+       }
+
+      if (TYPE_OVERFLOW_WRAPS (expr_type))
        {
          typedef FIXED_WIDE_INT (WIDE_INT_MAX_PRECISION * 2) vrp_int;
          typedef generic_wide_int

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