On 8/23/18 8:51 AM, Richard Biener wrote:
On Tue, Aug 21, 2018 at 7:35 PM Aldy Hernandez <al...@redhat.com> wrote:
On 08/21/2018 05:46 AM, Richard Biener wrote:
On Wed, Aug 15, 2018 at 3:33 AM Aldy Hernandez <al...@redhat.com> wrote:
Yeah, nice work. Few comments:
+ TYPE_OVERFLOW_UNDEFINED (expr_type),
+ TYPE_OVERFLOW_WRAPS (expr_type),
we no longer have the third state !UNDEFINED && !WRAPS so I suggest
to eliminate one for the other (just pass TYPE_OVERFLOW_UNDEFINED).
I'm confused. Then what shall I pass to
wide_int_range_multiplicative_op within wide_int_range_div? Are you
expecting to pass overflow_undefined to both the overflow_undefined and
overflow_wraps arguments in multiplicative_op? Or are you saying I
should get rid of overflow_wraps in both wide_int_range_div and
wide_int_range_multiplicative_op (plus all other users of
w_i_r_multiplicative_op)?
Yes, overflow_wraps == !overflow_undefined (well, OK, not exactly - there's
also TYPE_OVERFLOW_TRAPS, but not for pointers).
Let's sort this out as a followup. It somewhat felt odd / inconsistent.
I think the wide-int routines want to know whether the operation may
overflow or not and if it may then it simply assumes wrapping behavior.
When overflow is undefined or if it traps the overflow isn't observed
in the result ...
As promised, here is a patch merging the TYPE_OVERFLOW_UNDEFINED and
TYPE_OVERFLOW_WRAPS flags in the wide_int_range* routines.
OK pending tests?
Aldy
commit dca640a3b3a018e42a852006ccaf09da3b0acaff
Author: Aldy Hernandez <al...@redhat.com>
Date: Wed Oct 17 11:46:57 2018 +0200
* tree-vrp.c (extract_range_from_multiplicative_op): Remove
overflow wraps argument.
(extract_range_from_binary_expr_1): Do not pass overflow wraps to
wide_int_range_multiplicative_op.
* wide-int-range.cc (wide_int_range_mult_wrapping): Remove
overflow wraps argument.
(wide_int_range_multiplicative_op): Same.
(wide_int_range_lshift): Same.
(wide_int_range_div): Same.
* wide-int-range.h (wide_int_range_multiplicative_op): Same.
(wide_int_range_lshift): Same.
(wide_int_range_div): Same.
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4768b9635f8..6cfaac1690d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,18 @@
+2018-10-17 Aldy Hernandez <al...@redhat.com>
+
+ * tree-vrp.c (extract_range_from_multiplicative_op): Remove
+ overflow wraps argument.
+ (extract_range_from_binary_expr_1): Do not pass overflow wraps to
+ wide_int_range_multiplicative_op.
+ * wide-int-range.cc (wide_int_range_mult_wrapping): Remove
+ overflow wraps argument.
+ (wide_int_range_multiplicative_op): Same.
+ (wide_int_range_lshift): Same.
+ (wide_int_range_div): Same.
+ * wide-int-range.h (wide_int_range_multiplicative_op): Same.
+ (wide_int_range_lshift): Same.
+ (wide_int_range_div): Same.
+
2018-10-17 Aldy Hernandez <al...@redhat.com>
* wide-int-range.h (wide_int_range_shift_undefined_p): Adjust to
diff --git a/gcc/tree-vrp.c b/gcc/tree-vrp.c
index c519613bb28..0a42da7005e 100644
--- a/gcc/tree-vrp.c
+++ b/gcc/tree-vrp.c
@@ -1003,13 +1003,12 @@ extract_range_from_multiplicative_op (value_range *vr,
wide_int vr1_lb = wi::to_wide (vr1->min);
wide_int vr1_ub = wi::to_wide (vr1->max);
bool overflow_undefined = TYPE_OVERFLOW_UNDEFINED (type);
- bool overflow_wraps = TYPE_OVERFLOW_WRAPS (type);
unsigned prec = TYPE_PRECISION (type);
if (wide_int_range_multiplicative_op (res_lb, res_ub,
- code, TYPE_SIGN (type), prec,
- vr0_lb, vr0_ub, vr1_lb, vr1_ub,
- overflow_undefined, overflow_wraps))
+ code, TYPE_SIGN (type), prec,
+ vr0_lb, vr0_ub, vr1_lb, vr1_ub,
+ overflow_undefined))
set_and_canonicalize_value_range (vr, VR_RANGE,
wide_int_to_tree (type, res_lb),
wide_int_to_tree (type, res_ub), NULL);
@@ -1549,8 +1548,7 @@ extract_range_from_binary_expr_1 (value_range *vr,
wi::to_wide (vr0.max),
wi::to_wide (vr1.min),
wi::to_wide (vr1.max),
- TYPE_OVERFLOW_UNDEFINED (expr_type),
- TYPE_OVERFLOW_WRAPS (expr_type)))
+ TYPE_OVERFLOW_UNDEFINED (expr_type)))
{
min = wide_int_to_tree (expr_type, res_lb);
max = wide_int_to_tree (expr_type, res_ub);
@@ -1595,7 +1593,6 @@ extract_range_from_binary_expr_1 (value_range *vr,
dividend_min, dividend_max,
divisor_min, divisor_max,
TYPE_OVERFLOW_UNDEFINED (expr_type),
- TYPE_OVERFLOW_WRAPS (expr_type),
extra_range_p, extra_min, extra_max))
{
set_value_range_to_varying (vr);
diff --git a/gcc/wide-int-range.cc b/gcc/wide-int-range.cc
index a85fe9f9ad7..8978b5aecfd 100644
--- a/gcc/wide-int-range.cc
+++ b/gcc/wide-int-range.cc
@@ -268,7 +268,7 @@ wide_int_range_mult_wrapping (wide_int &res_lb,
Return TRUE if we were able to perform the operation.
- NOTE: If code is MULT_EXPR and TYPE_OVERFLOW_WRAPS, the resulting
+ NOTE: If code is MULT_EXPR and !TYPE_OVERFLOW_UNDEFINED, the resulting
range must be canonicalized by the caller because its components
may be swapped. */
@@ -281,8 +281,7 @@ wide_int_range_multiplicative_op (wide_int &res_lb, wide_int &res_ub,
const wide_int &vr0_ub,
const wide_int &vr1_lb,
const wide_int &vr1_ub,
- bool overflow_undefined,
- bool overflow_wraps)
+ bool overflow_undefined)
{
/* Multiplications, divisions and shifts are a bit tricky to handle,
depending on the mix of signs we have in the two ranges, we
@@ -296,7 +295,7 @@ wide_int_range_multiplicative_op (wide_int &res_lb, wide_int &res_ub,
(MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP
MAX1) and then figure the smallest and largest values to form
the new range. */
- if (code == MULT_EXPR && overflow_wraps)
+ if (code == MULT_EXPR && !overflow_undefined)
return wide_int_range_mult_wrapping (res_lb, res_ub,
sign, prec,
vr0_lb, vr0_ub, vr1_lb, vr1_ub);
@@ -320,7 +319,7 @@ wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
signop sign, unsigned prec,
const wide_int &vr0_lb, const wide_int &vr0_ub,
const wide_int &vr1_lb, const wide_int &vr1_ub,
- bool overflow_undefined, bool overflow_wraps)
+ bool overflow_undefined)
{
/* Transform left shifts by constants into multiplies. */
if (wi::eq_p (vr1_lb, vr1_ub))
@@ -330,8 +329,7 @@ wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
return wide_int_range_multiplicative_op (res_lb, res_ub,
MULT_EXPR, sign, prec,
vr0_lb, vr0_ub, tmp, tmp,
- overflow_undefined,
- /*overflow_wraps=*/true);
+ /*overflow_undefined=*/false);
}
int overflow_pos = prec;
@@ -387,8 +385,7 @@ wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
LSHIFT_EXPR, sign, prec,
vr0_lb, vr0_ub,
vr1_lb, vr1_ub,
- overflow_undefined,
- overflow_wraps);
+ overflow_undefined);
return false;
}
@@ -785,7 +782,6 @@ wide_int_range_div (wide_int &wmin, wide_int &wmax,
const wide_int ÷nd_min, const wide_int ÷nd_max,
const wide_int &divisor_min, const wide_int &divisor_max,
bool overflow_undefined,
- bool overflow_wraps,
bool &extra_range_p,
wide_int &extra_min, wide_int &extra_max)
{
@@ -796,8 +792,7 @@ wide_int_range_div (wide_int &wmin, wide_int &wmax,
return wide_int_range_multiplicative_op (wmin, wmax, code, sign, prec,
dividend_min, dividend_max,
divisor_min, divisor_max,
- overflow_undefined,
- overflow_wraps);
+ overflow_undefined);
/* If flag_non_call_exceptions, we must not eliminate a division
by zero. */
@@ -818,8 +813,7 @@ wide_int_range_div (wide_int &wmin, wide_int &wmax,
code, sign, prec,
dividend_min, dividend_max,
divisor_min, wi::minus_one (prec),
- overflow_undefined,
- overflow_wraps))
+ overflow_undefined))
return false;
extra_range_p = true;
}
@@ -831,8 +825,7 @@ wide_int_range_div (wide_int &wmin, wide_int &wmax,
code, sign, prec,
dividend_min, dividend_max,
wi::one (prec), divisor_max,
- overflow_undefined,
- overflow_wraps))
+ overflow_undefined))
return false;
}
else
diff --git a/gcc/wide-int-range.h b/gcc/wide-int-range.h
index 589fdea4df6..f8b7e7f47a2 100644
--- a/gcc/wide-int-range.h
+++ b/gcc/wide-int-range.h
@@ -42,14 +42,12 @@ extern bool wide_int_range_multiplicative_op (wide_int &res_lb,
const wide_int &vr0_ub,
const wide_int &vr1_lb,
const wide_int &vr1_ub,
- bool overflow_undefined,
- bool overflow_wraps);
+ bool overflow_undefined);
extern bool wide_int_range_lshift (wide_int &res_lb, wide_int &res_ub,
signop sign, unsigned prec,
const wide_int &, const wide_int &,
const wide_int &, const wide_int &,
- bool overflow_undefined,
- bool overflow_wraps);
+ bool overflow_undefined);
extern void wide_int_range_set_zero_nonzero_bits (signop,
const wide_int &lb,
const wide_int &ub,
@@ -124,7 +122,6 @@ extern bool wide_int_range_div (wide_int &wmin, wide_int &wmax,
const wide_int &divisor_min,
const wide_int &divisor_max,
bool overflow_undefined,
- bool overflow_wraps,
bool &extra_range_p,
wide_int &extra_min, wide_int &extra_max);
