From c01d6ad948e9e46fbc3695c7c3f45090c4d82db7 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Fri, 4 Jul 2014 00:11:21 +0200 Subject: re PR tree-optimization/61682 (wrong code at -O3 on x86_64-linux-gnu) PR tree-optimization/61682 * wide-int.cc (wi::mul_internal): Handle high correctly for umul_ppmm using cases and when one of the operands is equal to 1. * gcc.c-torture/execute/pr61682.c: New test. From-SVN: r212273 --- gcc/wide-int.cc | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) (limited to 'gcc/wide-int.cc') diff --git a/gcc/wide-int.cc b/gcc/wide-int.cc index ed7f01b..c33d10e 100644 --- a/gcc/wide-int.cc +++ b/gcc/wide-int.cc @@ -1,5 +1,5 @@ /* Operations with very long integers. - Copyright (C) 2012-2013 Free Software Foundation, Inc. + Copyright (C) 2012-2014 Free Software Foundation, Inc. Contributed by Kenneth Zadeck This file is part of GCC. @@ -1282,6 +1282,12 @@ wi::mul_internal (HOST_WIDE_INT *val, const HOST_WIDE_INT *op1val, && wi::fits_uhwi_p (op1) && wi::fits_uhwi_p (op2)) { + /* This case never overflows. */ + if (high) + { + val[0] = 0; + return 1; + } umul_ppmm (val[1], val[0], op1.ulow (), op2.ulow ()); return 1 + (val[1] != 0 || val[0] < 0); } @@ -1294,6 +1300,8 @@ wi::mul_internal (HOST_WIDE_INT *val, const HOST_WIDE_INT *op1val, umul_ppmm (upper, val[0], op1.ulow (), op2.ulow ()); if (needs_overflow) *overflow = (upper != 0); + if (high) + val[0] = upper; return 1; } } @@ -1302,12 +1310,22 @@ wi::mul_internal (HOST_WIDE_INT *val, const HOST_WIDE_INT *op1val, /* Handle multiplications by 1. */ if (op1 == 1) { + if (high) + { + val[0] = wi::neg_p (op2, sgn) ? -1 : 0; + return 1; + } for (i = 0; i < op2len; i++) val[i] = op2val[i]; return op2len; } if (op2 == 1) { + if (high) + { + val[0] = wi::neg_p (op1, sgn) ? -1 : 0; + return 1; + } for (i = 0; i < op1len; i++) val[i] = op1val[i]; return op1len; -- cgit v1.1