From 56e1a4d7127256bb3f476a6d93954b1948b03985 Mon Sep 17 00:00:00 2001 From: Markus Trippelsdorf Date: Thu, 1 Dec 2016 14:59:03 +0000 Subject: [PATCH] Fix PR tree-optimization/78598 - tree-ssa-loop-prefetch.c:835:16: runtime error: signed integer overflow Using bootstrap-ubsan gcc to build mplayer shows: tree-ssa-loop-prefetch.c:835:16: runtime error: signed integer overflow: 288230376151711743 * 64 cannot be represented in type 'long int' Here signed und unsigned integers are mixed in a division resulting in bogus values: (-83 + 64ULL -1) / 64ULL) == 288230376151711743 Fixed by casting the unsigned parameter to signed. PR tree-optimization/78598 * tree-ssa-loop-prefetch.c (ddown): Cast to signed to avoid overflows. From-SVN: r243113 --- gcc/ChangeLog | 6 ++++++ gcc/tree-ssa-loop-prefetch.c | 4 ++-- 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b90cbc6..17e9831 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,11 @@ 2016-12-01 Markus Trippelsdorf + PR tree-optimization/78598 + * tree-ssa-loop-prefetch.c (ddown): Cast to signed to avoid + overflows. + +2016-12-01 Markus Trippelsdorf + PR rtl-optimization/78596 * combine.c (simplify_comparison): Cast to unsigned to avoid left shifting of negative value. diff --git a/gcc/tree-ssa-loop-prefetch.c b/gcc/tree-ssa-loop-prefetch.c index 0a2ee5e..ead2543 100644 --- a/gcc/tree-ssa-loop-prefetch.c +++ b/gcc/tree-ssa-loop-prefetch.c @@ -700,9 +700,9 @@ ddown (HOST_WIDE_INT x, unsigned HOST_WIDE_INT by) gcc_assert (by > 0); if (x >= 0) - return x / by; + return x / (HOST_WIDE_INT) by; else - return (x + by - 1) / by; + return (x + (HOST_WIDE_INT) by - 1) / (HOST_WIDE_INT) by; } /* Given a CACHE_LINE_SIZE and two inductive memory references -- 2.7.4