diff options
author | Andrew Pinski <apinski@marvell.com> | 2023-08-09 13:49:24 -0700 |
---|---|---|
committer | Andrew Pinski <apinski@marvell.com> | 2023-08-10 23:51:07 -0700 |
commit | f956c232649e4bb7482786cd54e5d5b4085cd00a (patch) | |
tree | ca36a466e6fcf6bba9662c833b2b1e46b5d90ac2 | |
parent | 68783211f660a501dee203aec11dae99bf9808ba (diff) | |
download | gcc-f956c232649e4bb7482786cd54e5d5b4085cd00a.zip gcc-f956c232649e4bb7482786cd54e5d5b4085cd00a.tar.gz gcc-f956c232649e4bb7482786cd54e5d5b4085cd00a.tar.bz2 |
Fix PR 110954: wrong code with cmp | !cmp
This was an oversight on my part forgetting that
cmp will might have a different true value than all ones
but will have a value of 1 in most cases.
This means if we have `(f < 0) | !(f < 0)` we would
optimize this to -1 rather than just 1.
This is version 2 of the patch.
Decided to go down a different route than just checking if
the precission was 1 inside bitwise_inverted_equal_p.
So instead bitwise_inverted_equal_p gets passed an argument
that will be set if there was a comparison that was being compared
and the user of bitwise_inverted_equal_p decides what needs to be done.
In most uses of bitwise_inverted_equal_p, the check will be
`!wascmp || element_precision (type) == 1` .
But in the case of `a & ~a` and `a ^| ~a` we can handle the case
of wascmp by using constant_boolean_node isntead.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/110954
gcc/ChangeLog:
* generic-match-head.cc (bitwise_inverted_equal_p): Add
wascmp argument and set it accordingly.
* gimple-match-head.cc (bitwise_inverted_equal_p): Add
wascmp argument to the macro.
(gimple_bitwise_inverted_equal_p): Add
wascmp argument and set it accordingly.
* match.pd (`a & ~a`, `a ^| ~a`): Update call
to bitwise_inverted_equal_p and handle wascmp case.
(`(~x | y) & x`, `(~x | y) & x`, `a?~t:t`): Update
call to bitwise_inverted_equal_p and check to see
if was !wascmp or if precision was 1.
gcc/testsuite/ChangeLog:
* gcc.c-torture/execute/pr110954-1.c: New test.
-rw-r--r-- | gcc/generic-match-head.cc | 4 | ||||
-rw-r--r-- | gcc/gimple-match-head.cc | 8 | ||||
-rw-r--r-- | gcc/match.pd | 41 | ||||
-rw-r--r-- | gcc/testsuite/gcc.c-torture/execute/pr110954-1.c | 10 |
4 files changed, 43 insertions, 20 deletions
diff --git a/gcc/generic-match-head.cc b/gcc/generic-match-head.cc index ddaf22f..f40a35c 100644 --- a/gcc/generic-match-head.cc +++ b/gcc/generic-match-head.cc @@ -127,10 +127,11 @@ bitwise_equal_p (tree expr1, tree expr2) The types can differ through nop conversions. */ static inline bool -bitwise_inverted_equal_p (tree expr1, tree expr2) +bitwise_inverted_equal_p (tree expr1, tree expr2, bool &wascmp) { STRIP_NOPS (expr1); STRIP_NOPS (expr2); + wascmp = false; if (expr1 == expr2) return false; if (!tree_nop_conversion_p (TREE_TYPE (expr1), TREE_TYPE (expr2))) @@ -150,6 +151,7 @@ bitwise_inverted_equal_p (tree expr1, tree expr2) { tree op10 = TREE_OPERAND (expr1, 0); tree op20 = TREE_OPERAND (expr2, 0); + wascmp = true; if (!operand_equal_p (op10, op20)) return false; tree op11 = TREE_OPERAND (expr1, 1); diff --git a/gcc/gimple-match-head.cc b/gcc/gimple-match-head.cc index a097a49..ea6387a 100644 --- a/gcc/gimple-match-head.cc +++ b/gcc/gimple-match-head.cc @@ -267,8 +267,8 @@ gimple_bitwise_equal_p (tree expr1, tree expr2, tree (*valueize) (tree)) /* Return true if EXPR1 and EXPR2 have the bitwise opposite value, but not necessarily same type. The types can differ through nop conversions. */ -#define bitwise_inverted_equal_p(expr1, expr2) \ - gimple_bitwise_inverted_equal_p (expr1, expr2, valueize) +#define bitwise_inverted_equal_p(expr1, expr2, wascmp) \ + gimple_bitwise_inverted_equal_p (expr1, expr2, wascmp, valueize) bool gimple_bit_not_with_nop (tree, tree *, tree (*) (tree)); @@ -277,8 +277,9 @@ bool gimple_maybe_cmp (tree, tree *, tree (*) (tree)); /* Helper function for bitwise_equal_p macro. */ static inline bool -gimple_bitwise_inverted_equal_p (tree expr1, tree expr2, tree (*valueize) (tree)) +gimple_bitwise_inverted_equal_p (tree expr1, tree expr2, bool &wascmp, tree (*valueize) (tree)) { + wascmp = false; if (expr1 == expr2) return false; if (!tree_nop_conversion_p (TREE_TYPE (expr1), TREE_TYPE (expr2))) @@ -331,6 +332,7 @@ gimple_bitwise_inverted_equal_p (tree expr1, tree expr2, tree (*valueize) (tree) tree op21 = do_valueize (valueize, gimple_assign_rhs2 (a2)); if (!operand_equal_p (op11, op21)) return false; + wascmp = true; if (invert_tree_comparison (gimple_assign_rhs_code (a1), HONOR_NANS (op10)) == gimple_assign_rhs_code (a2)) diff --git a/gcc/match.pd b/gcc/match.pd index fc630b6..6791060 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -1179,9 +1179,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* Simplify ~X & X as zero. */ (simplify (bit_and (convert? @0) (convert? @1)) - (if (types_match (TREE_TYPE (@0), TREE_TYPE (@1)) - && bitwise_inverted_equal_p (@0, @1)) - { build_zero_cst (type); })) + (with { bool wascmp; } + (if (types_match (TREE_TYPE (@0), TREE_TYPE (@1)) + && bitwise_inverted_equal_p (@0, @1, wascmp)) + { wascmp ? constant_boolean_node (false, type) : build_zero_cst (type); }))) /* PR71636: Transform x & ((1U << b) - 1) -> x & ~(~0U << b); */ (simplify @@ -1419,9 +1420,13 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (for op (bit_ior bit_xor) (simplify (op (convert? @0) (convert? @1)) - (if (types_match (TREE_TYPE (@0), TREE_TYPE (@1)) - && bitwise_inverted_equal_p (@0, @1)) - (convert { build_all_ones_cst (TREE_TYPE (@0)); })))) + (with { bool wascmp; } + (if (types_match (TREE_TYPE (@0), TREE_TYPE (@1)) + && bitwise_inverted_equal_p (@0, @1, wascmp)) + (convert + { wascmp + ? constant_boolean_node (true, type) + : build_all_ones_cst (TREE_TYPE (@0)); }))))) /* x ^ x -> 0 */ (simplify @@ -1969,8 +1974,10 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* (~x & y) | x -> x | y */ (simplify (bitop:c (rbitop:c @2 @1) @0) - (if (bitwise_inverted_equal_p (@0, @2)) - (bitop @0 @1)))) + (with { bool wascmp; } + (if (bitwise_inverted_equal_p (@0, @2, wascmp) + && (!wascmp || element_precision (type) == 1)) + (bitop @0 @1))))) /* ((x | y) & z) | x -> (z & y) | x */ (simplify @@ -6464,14 +6471,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) /* a?~t:t -> (-(a))^t */ (simplify (cond @0 @1 @2) - (if (INTEGRAL_TYPE_P (type) - && bitwise_inverted_equal_p (@1, @2)) - (with { - auto prec = TYPE_PRECISION (type); - auto unsign = TYPE_UNSIGNED (type); - tree inttype = build_nonstandard_integer_type (prec, unsign); - } - (convert (bit_xor (negate (convert:inttype @0)) (convert:inttype @2)))))) + (with { bool wascmp; } + (if (INTEGRAL_TYPE_P (type) + && bitwise_inverted_equal_p (@1, @2, wascmp) + && (!wascmp || element_precision (type) == 1)) + (with { + auto prec = TYPE_PRECISION (type); + auto unsign = TYPE_UNSIGNED (type); + tree inttype = build_nonstandard_integer_type (prec, unsign); + } + (convert (bit_xor (negate (convert:inttype @0)) (convert:inttype @2))))))) #endif /* Simplify pointer equality compares using PTA. */ diff --git a/gcc/testsuite/gcc.c-torture/execute/pr110954-1.c b/gcc/testsuite/gcc.c-torture/execute/pr110954-1.c new file mode 100644 index 0000000..8aad758 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/pr110954-1.c @@ -0,0 +1,10 @@ + +#define comparison (f < 0) +int main() { + int f = 0; + int d = comparison | !comparison; + if (d != 1) + __builtin_abort(); + return 0; +} + |