From 6355b2d5bb6870b770e00f7dc2b9ab275e3d6a9e Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Mon, 14 Jun 2004 19:45:08 +0200 Subject: [PATCH] re PR middle-end/15945 (Incorrect floating point optimization) PR middle-end/15945 * simplify-rtx.c (simplify_binary_operation): Don't optimize out Inf + -Inf, Inf - Inf, Inf / Inf and 0 * Inf if flag_trapping_math. From-SVN: r83121 --- gcc/ChangeLog | 6 ++++++ gcc/simplify-rtx.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6444b0602b2..d7faa5d7818 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2004-06-14 Jakub Jelinek + + PR middle-end/15945 + * simplify-rtx.c (simplify_binary_operation): Don't optimize out + Inf + -Inf, Inf - Inf, Inf / Inf and 0 * Inf if flag_trapping_math. + 2004-06-14 Zdenek Dvorak * opts.sh (var_args): Fix regexp. diff --git a/gcc/simplify-rtx.c b/gcc/simplify-rtx.c index fb80219155c..0d3b2bde45f 100644 --- a/gcc/simplify-rtx.c +++ b/gcc/simplify-rtx.c @@ -1277,6 +1277,41 @@ simplify_binary_operation (enum rtx_code code, enum machine_mode mode, && (flag_trapping_math || ! MODE_HAS_INFINITIES (mode))) return 0; + if (MODE_HAS_INFINITIES (mode) && HONOR_NANS (mode) + && flag_trapping_math + && REAL_VALUE_ISINF (f0) && REAL_VALUE_ISINF (f1)) + { + int s0 = REAL_VALUE_NEGATIVE (f0); + int s1 = REAL_VALUE_NEGATIVE (f1); + + switch (code) + { + case PLUS: + /* Inf + -Inf = NaN plus exception. */ + if (s0 != s1) + return 0; + break; + case MINUS: + /* Inf - Inf = NaN plus exception. */ + if (s0 == s1) + return 0; + break; + case DIV: + /* Inf / Inf = NaN plus exception. */ + return 0; + default: + break; + } + } + + if (code == MULT && MODE_HAS_INFINITIES (mode) && HONOR_NANS (mode) + && flag_trapping_math + && ((REAL_VALUE_ISINF (f0) && REAL_VALUES_EQUAL (f1, dconst0)) + || (REAL_VALUE_ISINF (f1) + && REAL_VALUES_EQUAL (f0, dconst0)))) + /* Inf * 0 = NaN plus exception. */ + return 0; + REAL_ARITHMETIC (value, rtx_to_tree_code (code), f0, f1); value = real_value_truncate (mode, value); -- 2.30.2