From 7040e90366fe1e8d4d78564335f3b3ea8e55234b Mon Sep 17 00:00:00 2001 From: Kyrylo Tkachov Date: Mon, 20 Jul 2015 12:51:45 +0000 Subject: [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 --- gcc/simplify-rtx.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) (limited to 'gcc/simplify-rtx.c') 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) -- cgit v1.1