On Thu, 2 Jun 2022, Jakub Jelinek wrote:
> Hi!
>
> The following patch is an incremental change to the PR30314 enhancement,
> this one handles signed types.
> For signed types (but still, the same for 1st and result element type
> and non-zero constant that fits into that type), we actually need to
> watch for overflow in direction to positive and negative infinity
> and it also depends on whether the cst operand is positive or negative.
> For __builtin_mul_overflow_p (x, cst, (stype) 0):
> For cst > 0, we can simplify it to:
> x > INT_MAX / cst || x < INT_MIN / cst
> aka:
> x + (unsigned) (INT_MIN / cst) > (unsigned) (INT_MAX / cst) - (unsigned)
> (INT_MIN / cst)
> and for cst < 0 to:
> x < INT_MAX / cst || x > INT_MIN / cst
> aka:
> x + (unsigned) (INT_MAX / cst) > (unsigned) (INT_MIN / cst) - (unsigned)
> (INT_MAX / cst)
>
> Additionally, I've added executable testcases, so we don't just check for
> the optimization to be performed, but also that it is correct (done that
> even for the other PR's testcase).
>
> Starting x86_64-linux and i686-linux bootstrap/regtest, ok for trunk if
> it passes them?
OK.
Thanks,
Richard.
> 2022-06-02 Jakub Jelinek <ja...@redhat.com>
>
> PR middle-end/30314
> PR middle-end/105777
> * match.pd (__builtin_mul_overflow_p (x, cst, (stype) 0) ->
> x > stype_max / cst || x < stype_min / cst): New simplification.
>
> * gcc.dg/tree-ssa/pr30314.c: Add noipa attribute to all functions.
> * gcc.dg/tree-ssa/pr105777.c: New test.
> * gcc.c-torture/execute/pr30314.c: New test.
> * gcc.c-torture/execute/pr105777.c: New test.
>
> --- gcc/match.pd.jj 2022-06-01 17:54:30.536372912 +0200
> +++ gcc/match.pd 2022-06-02 13:16:17.171415948 +0200
> @@ -5970,15 +5970,37 @@ (define_operator_list SYNC_FETCH_AND_AND
> (ovf @1 @0))))
>
> /* Optimize __builtin_mul_overflow_p (x, cst, (utype) 0) if all 3 types
> - are unsigned to x > (umax / cst). */
> + are unsigned to x > (umax / cst). Similarly for signed type, but
> + in that case it needs to be outside of a range. */
> (simplify
> (imagpart (IFN_MUL_OVERFLOW:cs@2 @0 integer_nonzerop@1))
> (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
> - && TYPE_UNSIGNED (TREE_TYPE (@0))
> && TYPE_MAX_VALUE (TREE_TYPE (@0))
> && types_match (TREE_TYPE (@0), TREE_TYPE (TREE_TYPE (@2)))
> && int_fits_type_p (@1, TREE_TYPE (@0)))
> - (convert (gt @0 (trunc_div! { TYPE_MAX_VALUE (TREE_TYPE (@0)); } @1)))))
> + (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
> + (convert (gt @0 (trunc_div! { TYPE_MAX_VALUE (TREE_TYPE (@0)); } @1)))
> + (if (TYPE_MIN_VALUE (TREE_TYPE (@0)))
> + (with
> + {
> + tree lo = int_const_binop (TRUNC_DIV_EXPR,
> + TYPE_MIN_VALUE (TREE_TYPE (@0)),
> + fold_convert (TREE_TYPE (@0), @1));
> + tree hi = int_const_binop (TRUNC_DIV_EXPR,
> + TYPE_MAX_VALUE (TREE_TYPE (@0)),
> + fold_convert (TREE_TYPE (@0), @1));
> + tree etype = range_check_type (TREE_TYPE (@0));
> + if (etype)
> + {
> + if (wi::neg_p (wi::to_wide (@1)))
> + std::swap (lo, hi);
> + lo = fold_convert (etype, lo);
> + hi = fold_convert (etype, hi);
> + hi = int_const_binop (MINUS_EXPR, hi, lo);
> + }
> + }
> + (if (etype)
> + (convert (gt (minus (convert:etype @0) { lo; }) { hi; }))))))))
>
> /* Simplification of math builtins. These rules must all be optimizations
> as well as IL simplifications. If there is a possibility that the new
> --- gcc/testsuite/gcc.dg/tree-ssa/pr30314.c.jj 2022-06-02
> 11:17:23.689835550 +0200
> +++ gcc/testsuite/gcc.dg/tree-ssa/pr30314.c 2022-06-02 14:23:19.294093445
> +0200
> @@ -7,25 +7,25 @@
> /* { dg-final { scan-tree-dump " > 102261126" "optimized" { target int32 } }
> } */
> /* { dg-final { scan-tree-dump " > 439208192231179800" "optimized" { target
> lp64 } } } */
>
> -int
> +__attribute__((noipa)) int
> foo (unsigned int x)
> {
> return __builtin_mul_overflow_p (x, 35U, 0U);
> }
>
> -int
> +__attribute__((noipa)) int
> bar (unsigned long int x)
> {
> return __builtin_mul_overflow_p (x, 35UL, 0UL);
> }
>
> -int
> +__attribute__((noipa)) int
> baz (unsigned int x)
> {
> return __builtin_mul_overflow_p (42, x, 0U);
> }
>
> -int
> +__attribute__((noipa)) int
> qux (unsigned long int x)
> {
> return __builtin_mul_overflow_p (42, x, 0UL);
> --- gcc/testsuite/gcc.dg/tree-ssa/pr105777.c.jj 2022-06-02
> 14:22:57.017328731 +0200
> +++ gcc/testsuite/gcc.dg/tree-ssa/pr105777.c 2022-06-02 14:19:29.399521503
> +0200
> @@ -0,0 +1,68 @@
> +/* PR middle-end/105777 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fdump-tree-optimized" } */
> +/* { dg-final { scan-tree-dump-not "\.MUL_OVERFLOW " "optimized" } } */
> +/* { dg-final { scan-tree-dump " \\+ 61356675;" "optimized" { target int32 }
> } } */
> +/* { dg-final { scan-tree-dump " > 122713350" "optimized" { target int32 } }
> } */
> +/* { dg-final { scan-tree-dump " \\+ 263524915338707880" "optimized" {
> target lp64 } } } */
> +/* { dg-final { scan-tree-dump " > 527049830677415760" "optimized" { target
> lp64 } } } */
> +/* { dg-final { scan-tree-dump " \\+ 51130563" "optimized" { target int32 }
> } } */
> +/* { dg-final { scan-tree-dump " > 102261126" "optimized" { target int32 } }
> } */
> +/* { dg-final { scan-tree-dump " \\+ 219604096115589900" "optimized" {
> target lp64 } } } */
> +/* { dg-final { scan-tree-dump " > 439208192231179800" "optimized" { target
> lp64 } } } */
> +/* { dg-final { scan-tree-dump " \\+ 55063683;" "optimized" { target int32 }
> } } */
> +/* { dg-final { scan-tree-dump " > 110127366" "optimized" { target int32 } }
> } */
> +/* { dg-final { scan-tree-dump " \\+ 236496718893712200" "optimized" {
> target lp64 } } } */
> +/* { dg-final { scan-tree-dump " > 472993437787424400" "optimized" { target
> lp64 } } } */
> +/* { dg-final { scan-tree-dump " \\+ 46684427" "optimized" { target int32 }
> } } */
> +/* { dg-final { scan-tree-dump " > 93368854" "optimized" { target int32 } }
> } */
> +/* { dg-final { scan-tree-dump " \\+ 200508087757712517" "optimized" {
> target lp64 } } } */
> +/* { dg-final { scan-tree-dump " > 401016175515425034" "optimized" { target
> lp64 } } } */
> +
> +__attribute__((noipa)) int
> +foo (int x)
> +{
> + return __builtin_mul_overflow_p (x, 35, 0);
> +}
> +
> +__attribute__((noipa)) int
> +bar (long int x)
> +{
> + return __builtin_mul_overflow_p (x, 35L, 0L);
> +}
> +
> +__attribute__((noipa)) int
> +baz (int x)
> +{
> + return __builtin_mul_overflow_p (42, x, 0);
> +}
> +
> +__attribute__((noipa)) int
> +qux (long int x)
> +{
> + return __builtin_mul_overflow_p (42, x, 0L);
> +}
> +
> +__attribute__((noipa)) int
> +corge (int x)
> +{
> + return __builtin_mul_overflow_p (x, -39, 0);
> +}
> +
> +__attribute__((noipa)) int
> +garply (long int x)
> +{
> + return __builtin_mul_overflow_p (x, -39L, 0L);
> +}
> +
> +__attribute__((noipa)) int
> +grault (int x)
> +{
> + return __builtin_mul_overflow_p (-46, x, 0);
> +}
> +
> +__attribute__((noipa)) int
> +waldo (long int x)
> +{
> + return __builtin_mul_overflow_p (-46, x, 0L);
> +}
> --- gcc/testsuite/gcc.c-torture/execute/pr30314.c.jj 2022-06-02
> 14:32:30.070276332 +0200
> +++ gcc/testsuite/gcc.c-torture/execute/pr30314.c 2022-06-02
> 14:32:22.121360286 +0200
> @@ -0,0 +1,29 @@
> +/* PR middle-end/30314 */
> +
> +#include "../../gcc.dg/tree-ssa/pr30314.c"
> +
> +int
> +main ()
> +{
> + if (foo (0) != 0
> + || foo (~0U / 35) != 0
> + || foo (~0U / 35 + 1) != 1
> + || foo (~0U) != 1)
> + __builtin_abort ();
> + if (bar (0) != 0
> + || bar (~0UL / 35) != 0
> + || bar (~0UL / 35 + 1) != 1
> + || bar (~0UL) != 1)
> + __builtin_abort ();
> + if (baz (0) != 0
> + || baz (~0U / 42) != 0
> + || baz (~0U / 42 + 1) != 1
> + || baz (~0U) != 1)
> + __builtin_abort ();
> + if (qux (0) != 0
> + || qux (~0UL / 42) != 0
> + || qux (~0UL / 42 + 1) != 1
> + || qux (~0UL) != 1)
> + __builtin_abort ();
> + return 0;
> +}
> --- gcc/testsuite/gcc.c-torture/execute/pr105777.c.jj 2022-06-02
> 14:32:50.287062810 +0200
> +++ gcc/testsuite/gcc.c-torture/execute/pr105777.c 2022-06-02
> 14:38:36.289409212 +0200
> @@ -0,0 +1,73 @@
> +/* PR middle-end/105777 */
> +
> +#include "../../gcc.dg/tree-ssa/pr105777.c"
> +
> +int
> +main ()
> +{
> + if (foo (0) != 0
> + || foo (__INT_MAX__ / 35) != 0
> + || foo (__INT_MAX__ / 35 + 1) != 1
> + || foo (__INT_MAX__) != 1
> + || foo ((-__INT_MAX__ - 1) / 35) != 0
> + || foo ((-__INT_MAX__ - 1) / 35 - 1) != 1
> + || foo (-__INT_MAX__ - 1) != 1)
> + __builtin_abort ();
> + if (bar (0) != 0
> + || bar (__LONG_MAX__ / 35) != 0
> + || bar (__LONG_MAX__ / 35 + 1) != 1
> + || bar (__LONG_MAX__) != 1
> + || bar ((-__LONG_MAX__ - 1) / 35) != 0
> + || bar ((-__LONG_MAX__ - 1) / 35 - 1) != 1
> + || bar (-__LONG_MAX__ - 1) != 1)
> + __builtin_abort ();
> + if (baz (0) != 0
> + || baz (__INT_MAX__ / 42) != 0
> + || baz (__INT_MAX__ / 42 + 1) != 1
> + || baz (__INT_MAX__) != 1
> + || baz ((-__INT_MAX__ - 1) / 42) != 0
> + || baz ((-__INT_MAX__ - 1) / 42 - 1) != 1
> + || baz (-__INT_MAX__ - 1) != 1)
> + __builtin_abort ();
> + if (qux (0) != 0
> + || qux (__LONG_MAX__ / 42) != 0
> + || qux (__LONG_MAX__ / 42 + 1) != 1
> + || qux (__LONG_MAX__) != 1
> + || qux ((-__LONG_MAX__ - 1) / 42) != 0
> + || qux ((-__LONG_MAX__ - 1) / 42 - 1) != 1
> + || qux (-__LONG_MAX__ - 1) != 1)
> + __builtin_abort ();
> + if (corge (0) != 0
> + || corge (__INT_MAX__ / -39) != 0
> + || corge (__INT_MAX__ / -39 - 1) != 1
> + || corge (__INT_MAX__) != 1
> + || corge ((-__INT_MAX__ - 1) / -39) != 0
> + || corge ((-__INT_MAX__ - 1) / -39 + 1) != 1
> + || corge (-__INT_MAX__ - 1) != 1)
> + __builtin_abort ();
> + if (garply (0) != 0
> + || garply (__LONG_MAX__ / -39) != 0
> + || garply (__LONG_MAX__ / -39 - 1) != 1
> + || garply (__LONG_MAX__) != 1
> + || garply ((-__LONG_MAX__ - 1) / -39) != 0
> + || garply ((-__LONG_MAX__ - 1) / -39 + 1) != 1
> + || garply (-__LONG_MAX__ - 1) != 1)
> + __builtin_abort ();
> + if (grault (0) != 0
> + || grault (__INT_MAX__ / -46) != 0
> + || grault (__INT_MAX__ / -46 - 1) != 1
> + || grault (__INT_MAX__) != 1
> + || grault ((-__INT_MAX__ - 1) / -46) != 0
> + || grault ((-__INT_MAX__ - 1) / -46 + 1) != 1
> + || grault (-__INT_MAX__ - 1) != 1)
> + __builtin_abort ();
> + if (waldo (0) != 0
> + || waldo (__LONG_MAX__ / -46) != 0
> + || waldo (__LONG_MAX__ / -46 - 1) != 1
> + || waldo (__LONG_MAX__) != 1
> + || waldo ((-__LONG_MAX__ - 1) / -46) != 0
> + || waldo ((-__LONG_MAX__ - 1) / -46 + 1) != 1
> + || waldo (-__LONG_MAX__ - 1) != 1)
> + __builtin_abort ();
> + return 0;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Ivo Totev, Andrew Myers, Andrew McDonald, Boudien Moerman;
HRB 36809 (AG Nuernberg)
