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| author | Kyrylo Tkachov <kyrylo.tkachov@arm.com> | 2015-07-20 12:51:45 +0000 |
|---|---|---|
| committer | Kyrylo Tkachov <ktkachov@gcc.gnu.org> | 2015-07-20 12:51:45 +0000 |
| commit | 7040e90366fe1e8d4d78564335f3b3ea8e55234b (patch) | |
| tree | b199851fd64c33575ae6c054bb768b03fabaf4d8 /gcc/simplify-rtx.c | |
| parent | 232c93296dd97e3b300fc61f0f4ea79be4faf963 (diff) | |
| download | gcc-7040e90366fe1e8d4d78564335f3b3ea8e55234b.zip gcc-7040e90366fe1e8d4d78564335f3b3ea8e55234b.tar.gz gcc-7040e90366fe1e8d4d78564335f3b3ea8e55234b.tar.bz2 | |
[simplify-rtx][2/2] Simplify - (y ? -x : x) -> (!y ? -x : x)
* simplify-rtx.c (simplify_unary_operation_1, NEG case):
(neg (x ? (neg y) : y)) -> !x ? (neg y) : y.
* gcc.target/aarch64/neg_abs_1.c: New test.
From-SVN: r225997
Diffstat (limited to 'gcc/simplify-rtx.c')
| -rw-r--r-- | gcc/simplify-rtx.c | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index fde9944..4332a42 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -957,6 +957,32 @@ simplify_unary_operation_1 (enum rtx_code code, machine_mode mode, rtx op) if (GET_CODE (op) == NEG) return XEXP (op, 0); + /* (neg (x ? (neg y) : y)) == !x ? (neg y) : y. + If comparison is not reversible use + x ? y : (neg y). */ + if (GET_CODE (op) == IF_THEN_ELSE) + { + rtx cond = XEXP (op, 0); + rtx true_rtx = XEXP (op, 1); + rtx false_rtx = XEXP (op, 2); + + if ((GET_CODE (true_rtx) == NEG + && rtx_equal_p (XEXP (true_rtx, 0), false_rtx)) + || (GET_CODE (false_rtx) == NEG + && rtx_equal_p (XEXP (false_rtx, 0), true_rtx))) + { + if (reversed_comparison_code (cond, NULL_RTX) != UNKNOWN) + temp = reversed_comparison (cond, mode); + else + { + temp = cond; + std::swap (true_rtx, false_rtx); + } + return simplify_gen_ternary (IF_THEN_ELSE, mode, + mode, temp, true_rtx, false_rtx); + } + } + /* (neg (plus X 1)) can become (not X). */ if (GET_CODE (op) == PLUS && XEXP (op, 1) == const1_rtx) |