On Tue, Jan 19, 2016 at 8:48 PM, Marek Polacek <pola...@redhat.com> wrote:
> Recently on IRC we've concluded that for GCC 5 the simplest solution
> will be to just disable the problematic pattern on GENERIC. So done
> in the following. (The problem was that the match.pd pattern created
> SAVE_EXPRs which then leaked into gimplification.)
>
> Bootstrapped/regtested on x86_64-linux, ok for 5?
Please instead wrap the pattern in
#if GIMPLE
...
#endif
and add a comment refering to the PR.
Ok with that change.
Thanks,
Richard.
> 2016-01-19 Marek Polacek <pola...@redhat.com>
>
> PR c/68513
> * match.pd ((x & ~m) | (y & m)): Only perform on GIMPLE.
>
> * gcc.dg/pr68513.c: New test.
>
> diff --git gcc/match.pd gcc/match.pd
> index e40720e..0b557e6 100644
> --- gcc/match.pd
> +++ gcc/match.pd
> @@ -385,8 +385,9 @@ along with GCC; see the file COPYING3. If not see
> /* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
> (simplify
> (bit_ior:c (bit_and:c@3 @0 (bit_not @2)) (bit_and:c@4 @1 @2))
> - (if ((TREE_CODE (@3) != SSA_NAME || has_single_use (@3))
> - && (TREE_CODE (@4) != SSA_NAME || has_single_use (@4)))
> + (if (GIMPLE
> + && (TREE_CODE (@3) != SSA_NAME || has_single_use (@3))
> + && (TREE_CODE (@4) != SSA_NAME || has_single_use (@4)))
> (bit_xor (bit_and (bit_xor @0 @1) @2) @0)))
>
>
> diff --git gcc/testsuite/gcc.dg/pr68513.c gcc/testsuite/gcc.dg/pr68513.c
> index e69de29..86f878d 100644
> --- gcc/testsuite/gcc.dg/pr68513.c
> +++ gcc/testsuite/gcc.dg/pr68513.c
> @@ -0,0 +1,125 @@
> +/* PR c/68513 */
> +/* { dg-do compile } */
> +/* { dg-options "-funsafe-math-optimizations -fno-math-errno -O
> -Wno-div-by-zero" } */
> +
> +int i;
> +unsigned u;
> +volatile int *e;
> +
> +#define E (i ? *e : 0)
> +
> +/* Can't trigger some of them because operand_equal_p will return false
> + for side-effects. */
> +
> +/* (x & ~m) | (y & m) -> ((x ^ y) & m) ^ x */
> +int
> +fn1 (void)
> +{
> + int r = 0;
> + r += (short) (E & ~u | i & u);
> + r += -(short) (E & ~u | i & u);
> + r += (short) -(E & ~u | i & u);
> + return r;
> +}
> +
> +/* sqrt(x) < y is x >= 0 && x != +Inf, when y is large. */
> +double
> +fn2 (void)
> +{
> + double r;
> + r = __builtin_sqrt (E) < __builtin_inf ();
> + return r;
> +}
> +
> +/* sqrt(x) < c is the same as x >= 0 && x < c*c. */
> +double
> +fn3 (void)
> +{
> + double r;
> + r = __builtin_sqrt (E) < 1.3;
> + return r;
> +}
> +
> +/* copysign(x,y)*copysign(x,y) -> x*x. */
> +double
> +fn4 (double y, double x)
> +{
> + return __builtin_copysign (E, y) * __builtin_copysign (E, y);
> +}
> +
> +/* x <= +Inf is the same as x == x, i.e. !isnan(x). */
> +int
> +fn5 (void)
> +{
> + return E <= __builtin_inf ();
> +}
> +
> +/* Fold (A & ~B) - (A & B) into (A ^ B) - B. */
> +int
> +fn6 (void)
> +{
> + return (i & ~E) - (i & E);
> +}
> +
> +/* Fold (A & B) - (A & ~B) into B - (A ^ B). */
> +int
> +fn7 (void)
> +{
> + return (i & E) - (i & ~E);
> +}
> +
> +/* x + (x & 1) -> (x + 1) & ~1 */
> +int
> +fn8 (void)
> +{
> + return E + (E & 1);
> +}
> +
> +/* Simplify comparison of something with itself. */
> +int
> +fn9 (void)
> +{
> + return E <= E | E >= E;
> +}
> +
> +/* Fold (A & ~B) - (A & B) into (A ^ B) - B. */
> +int
> +fn10 (void)
> +{
> + return (i & ~E) - (i & E);
> +}
> +
> +/* abs(x)*abs(x) -> x*x. Should be valid for all types. */
> +int
> +fn11 (void)
> +{
> + return __builtin_abs (E) * __builtin_abs (E);
> +}
> +
> +/* (x | CST1) & CST2 -> (x & CST2) | (CST1 & CST2) */
> +int
> +fn12 (void)
> +{
> + return (E | 11) & 12;
> +}
> +
> +/* fold_range_test */
> +int
> +fn13 (const char *s)
> +{
> + return s[E] != '\0' && s[E] != '/';
> +}
> +
> +/* fold_comparison */
> +int
> +fn14 (void)
> +{
> + return (!!i ? : (u *= E / 0)) >= (u = E);
> +}
> +
> +/* fold_mult_zconjz */
> +_Complex int
> +fn15 (_Complex volatile int *z)
> +{
> + return *z * ~*z;
> +}
>
> Marek
