From cd47cd4b5eb2dfa7a3190e46a3ae93cc87dbe6b1 Mon Sep 17 00:00:00 2001 From: "Vladimir N. Makarov" Date: Thu, 2 Dec 2021 12:31:28 -0500 Subject: [PATCH] [PR103437] Make backup code for overflow conditional Switch off long long variant overflow code by preprocessor if the build compiler has __builtin_smul_overflow. gcc/ChangeLog: PR rtl-optimization/103437 * ira-color.c (setup_allocno_priorities): Switch off backup code for overflow if compiler has __builtin_smul_overflow. Use < for comparison with -INT_MAX. --- gcc/ira-color.c | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-) diff --git a/gcc/ira-color.c b/gcc/ira-color.c index 3b19a58..a1b0277 100644 --- a/gcc/ira-color.c +++ b/gcc/ira-color.c @@ -2797,7 +2797,6 @@ static void setup_allocno_priorities (ira_allocno_t *consideration_allocnos, int n) { int i, length, nrefs, priority, max_priority, mult, diff; - bool overflow_backup_p = true; ira_allocno_t a; max_priority = 0; @@ -2810,27 +2809,27 @@ setup_allocno_priorities (ira_allocno_t *consideration_allocnos, int n) ira_assert (mult >= 0); mult *= ira_reg_class_max_nregs[ALLOCNO_CLASS (a)][ALLOCNO_MODE (a)]; diff = ALLOCNO_MEMORY_COST (a) - ALLOCNO_CLASS_COST (a); - /* Multiplication can overflow for very large functions. - Check the overflow and constrain the result if necessary: */ #ifdef __has_builtin #if __has_builtin(__builtin_smul_overflow) - overflow_backup_p = false; +#define HAS_SMUL_OVERFLOW +#endif +#endif + /* Multiplication can overflow for very large functions. + Check the overflow and constrain the result if necessary: */ +#ifdef HAS_SMUL_OVERFLOW if (__builtin_smul_overflow (mult, diff, &priority) - || priority <= -INT_MAX) + || priority < -INT_MAX) priority = diff >= 0 ? INT_MAX : -INT_MAX; +#else + static_assert + (sizeof (long long) >= 2 * sizeof (int), + "overflow code does not work for such int and long long sizes"); + long long priorityll = (long long) mult * diff; + if (priorityll < -INT_MAX || priorityll > INT_MAX) + priority = diff >= 0 ? INT_MAX : -INT_MAX; + else + priority = priorityll; #endif -#endif - if (overflow_backup_p) - { - static_assert - (sizeof (long long) >= 2 * sizeof (int), - "overflow code does not work for such int and long long sizes"); - long long priorityll = (long long) mult * diff; - if (priorityll < -INT_MAX || priorityll > INT_MAX) - priority = diff >= 0 ? INT_MAX : -INT_MAX; - else - priority = priorityll; - } allocno_priorities[ALLOCNO_NUM (a)] = priority; if (priority < 0) priority = -priority; -- 2.7.4