From 5147bf6a236993578d316dfe7c7e7182da1cdf90 Mon Sep 17 00:00:00 2001 From: Alexandre Oliva Date: Wed, 16 Jan 2013 04:31:30 +0000 Subject: [PATCH] re PR rtl-optimization/55547 (Alias analysis does not handle AND addresses correctly) PR rtl-optimization/55547 PR rtl-optimization/53827 PR debug/53671 PR debug/49888 * alias.c (memrefs_conflict_p): Set sizes to negative after AND adjustments. From-SVN: r195227 --- gcc/ChangeLog | 9 +++++++++ gcc/alias.c | 18 +++++++++++++----- 2 files changed, 22 insertions(+), 5 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index e9220f5f8c6..6f7441e8b23 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,12 @@ +2013-01-16 Alexandre Oliva + + PR rtl-optimization/55547 + PR rtl-optimization/53827 + PR debug/53671 + PR debug/49888 + * alias.c (memrefs_conflict_p): Set sizes to negative after + AND adjustments. + 2013-01-15 Jakub Jelinek PR target/55940 diff --git a/gcc/alias.c b/gcc/alias.c index df328ec9d73..9a386dde382 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -2080,14 +2080,20 @@ memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c) /* Deal with alignment ANDs by adjusting offset and size so as to cover the maximum range, without taking any previously known - alignment into account. */ + alignment into account. Make a size negative after such an + adjustments, so that, if we end up with e.g. two SYMBOL_REFs, we + assume a potential overlap, because they may end up in contiguous + memory locations and the stricter-alignment access may span over + part of both. */ if (GET_CODE (x) == AND && CONST_INT_P (XEXP (x, 1))) { HOST_WIDE_INT sc = INTVAL (XEXP (x, 1)); unsigned HOST_WIDE_INT uc = sc; - if (xsize > 0 && sc < 0 && -uc == (uc & -uc)) + if (sc < 0 && -uc == (uc & -uc)) { - xsize -= sc + 1; + if (xsize > 0) + xsize = -xsize; + xsize += sc + 1; c -= sc + 1; return memrefs_conflict_p (xsize, canon_rtx (XEXP (x, 0)), ysize, y, c); @@ -2097,9 +2103,11 @@ memrefs_conflict_p (int xsize, rtx x, int ysize, rtx y, HOST_WIDE_INT c) { HOST_WIDE_INT sc = INTVAL (XEXP (y, 1)); unsigned HOST_WIDE_INT uc = sc; - if (ysize > 0 && sc < 0 && -uc == (uc & -uc)) + if (sc < 0 && -uc == (uc & -uc)) { - ysize -= sc + 1; + if (ysize > 0) + ysize = -ysize; + ysize += sc + 1; c += sc + 1; return memrefs_conflict_p (xsize, x, ysize, canon_rtx (XEXP (y, 0)), c); -- 2.30.2