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| author | Andrew Pinski <apinski@marvell.com> | 2023-05-16 14:26:41 -0700 |
|---|---|---|
| committer | Andrew Pinski <apinski@marvell.com> | 2023-05-30 08:43:23 -0700 |
| commit | 45466eecf5ef669164c0922e5be8fd288b144886 (patch) | |
| tree | 7efdbe9befafc1337527c3567ac6a2b2f3e46691 /gcc/fold-const.cc | |
| parent | 17cca3c43e2f496dcef0ba79e04979b49439e0c3 (diff) | |
| download | gcc-45466eecf5ef669164c0922e5be8fd288b144886.zip gcc-45466eecf5ef669164c0922e5be8fd288b144886.tar.gz gcc-45466eecf5ef669164c0922e5be8fd288b144886.tar.bz2 | |
Add a != MIN/MAX_VALUE_CST ? CST-+1 : a to minmax_from_comparison
This patch adds the support for match that was implemented for PR 87913 in phiopt.
It implements it by adding support to minmax_from_comparison for the check.
It uses the range information if available which allows to produce MIN/MAX expression
when comparing against the lower/upper bound of the range instead of lower/upper
of the type.
minmax-20.c is the new testcase which tests the ranges part.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
gcc/ChangeLog:
* fold-const.cc (minmax_from_comparison): Add support for NE_EXPR.
* match.pd ((cond (cmp (convert1? x) c1) (convert2? x) c2) pattern):
Add ne as a possible cmp.
((a CMP b) ? minmax<a, c> : minmax<b, c> pattern): Likewise.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/minmax-22.c: New test.
Diffstat (limited to 'gcc/fold-const.cc')
| -rw-r--r-- | gcc/fold-const.cc | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc index 5752150..84b0d06 100644 --- a/gcc/fold-const.cc +++ b/gcc/fold-const.cc @@ -173,6 +173,19 @@ minmax_from_comparison (tree_code cmp, tree exp0, tree exp1, tree exp2, tree exp /* X > Y - 1 equals to X >= Y. */ if (cmp == GT_EXPR) code = GE_EXPR; + /* a != MIN_RANGE<a> ? a : MIN_RANGE<a>+1 -> MAX_EXPR<MIN_RANGE<a>+1, a> */ + if (cmp == NE_EXPR && TREE_CODE (exp0) == SSA_NAME) + { + value_range r; + get_range_query (cfun)->range_of_expr (r, exp0); + if (r.undefined_p ()) + r.set_varying (TREE_TYPE (exp0)); + + widest_int min = widest_int::from (r.lower_bound (), + TYPE_SIGN (TREE_TYPE (exp0))); + if (min == wi::to_widest (exp1)) + code = MAX_EXPR; + } } if (wi::to_widest (exp1) == (wi::to_widest (exp3) + 1)) { @@ -182,6 +195,19 @@ minmax_from_comparison (tree_code cmp, tree exp0, tree exp1, tree exp2, tree exp /* X >= Y + 1 equals to X > Y. */ if (cmp == GE_EXPR) code = GT_EXPR; + /* a != MAX_RANGE<a> ? a : MAX_RANGE<a>-1 -> MIN_EXPR<MIN_RANGE<a>-1, a> */ + if (cmp == NE_EXPR && TREE_CODE (exp0) == SSA_NAME) + { + value_range r; + get_range_query (cfun)->range_of_expr (r, exp0); + if (r.undefined_p ()) + r.set_varying (TREE_TYPE (exp0)); + + widest_int max = widest_int::from (r.upper_bound (), + TYPE_SIGN (TREE_TYPE (exp0))); + if (max == wi::to_widest (exp1)) + code = MIN_EXPR; + } } } if (code != ERROR_MARK |