Now that GCC 4.9 branch is opened again and GCC 4.8 branch still open, is the following backported patch ok for both branches?
Best regards, Thomas > -----Original Message----- > From: gcc-patches-ow...@gcc.gnu.org [mailto:gcc-patches- > ow...@gcc.gnu.org] On Behalf Of Thomas Preud'homme > Sent: Thursday, June 26, 2014 9:11 AM > To: 'Jakub Jelinek' > Cc: Richard Biener; GCC Patches > Subject: RE: [PATCH] Fix PR61375: cancel bswap optimization when value > doesn't fit in a HOST_WIDE_INT > > Ok, what about the following patch and associated ChangeLog entries? > > 2014-06-24 Thomas Preud'homme <thomas.preudho...@arm.com> > > PR tree-optimization/61375 > * tree-ssa-math-opts.c (find_bswap_or_nop_1): Cancel optimization > if > symbolic number cannot be represented in an unsigned > HOST_WIDE_INT. > (execute_optimize_bswap): Cancel optimization if CHAR_BIT != 8. > > 2014-06-24 Thomas Preud'homme <thomas.preudho...@arm.com> > > PR tree-optimization/61375 > * gcc.c-torture/execute/pr61375-1.c: New test. > > > diff --git a/gcc/testsuite/gcc.c-torture/execute/pr61375.c > b/gcc/testsuite/gcc.c-torture/execute/pr61375.c > new file mode 100644 > index 0000000..6fb4693 > --- /dev/null > +++ b/gcc/testsuite/gcc.c-torture/execute/pr61375.c > @@ -0,0 +1,35 @@ > +#ifdef __UINT64_TYPE__ > +typedef __UINT64_TYPE__ uint64_t; > +#else > +typedef unsigned long long uint64_t; > +#endif > + > +#ifndef __SIZEOF_INT128__ > +#define __int128 long long > +#endif > + > +/* Some version of bswap optimization would ICE when analyzing a mask > constant > + too big for an HOST_WIDE_INT (PR61375). */ > + > +__attribute__ ((noinline, noclone)) uint64_t > +uint128_central_bitsi_ior (unsigned __int128 in1, uint64_t in2) > +{ > + __int128 mask = (__int128)0xffff << 56; > + return ((in1 & mask) >> 56) | in2; > +} > + > +int > +main (int argc) > +{ > + __int128 in = 1; > +#ifdef __SIZEOF_INT128__ > + in <<= 64; > +#endif > + if (sizeof (uint64_t) * __CHAR_BIT__ != 64) > + return 0; > + if (sizeof (unsigned __int128) * __CHAR_BIT__ != 128) > + return 0; > + if (uint128_central_bitsi_ior (in, 2) != 0x102) > + __builtin_abort (); > + return 0; > +} > diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c > index 9ff857c..045bf48 100644 > --- a/gcc/tree-ssa-math-opts.c > +++ b/gcc/tree-ssa-math-opts.c > @@ -1740,6 +1740,8 @@ find_bswap_1 (gimple stmt, struct > symbolic_number *n, int limit) > n->size = TYPE_PRECISION (TREE_TYPE (rhs1)); > if (n->size % BITS_PER_UNIT != 0) > return NULL_TREE; > + if (n->size > HOST_BITS_PER_WIDEST_INT) > + return NULL_TREE; > n->size /= BITS_PER_UNIT; > n->n = (sizeof (HOST_WIDEST_INT) < 8 ? 0 : > (unsigned HOST_WIDEST_INT)0x08070605 << 32 | > 0x04030201); > @@ -1781,6 +1783,8 @@ find_bswap_1 (gimple stmt, struct > symbolic_number *n, int limit) > type_size = TYPE_PRECISION (gimple_expr_type (stmt)); > if (type_size % BITS_PER_UNIT != 0) > return NULL_TREE; > + if (type_size > (int) HOST_BITS_PER_WIDEST_INT) > + return NULL_TREE; > > if (type_size / BITS_PER_UNIT < (int)(sizeof (HOST_WIDEST_INT))) > { > @@ -1911,7 +1915,7 @@ execute_optimize_bswap (void) > bool changed = false; > tree bswap16_type = NULL_TREE, bswap32_type = NULL_TREE, > bswap64_type = NULL_TREE; > > - if (BITS_PER_UNIT != 8) > + if (BITS_PER_UNIT != 8 || CHAR_BIT != 8) > return 0; > > if (sizeof (HOST_WIDEST_INT) < 8) > > Is this ok for 4.8 and 4.9 branches? > > Best regards, > > Thomas > >
