From 5da49a9d153a00776bba423734630b8d361dc53f Mon Sep 17 00:00:00 2001 From: Kai Tietz Date: Mon, 27 Jun 2011 15:44:52 +0200 Subject: [PATCH] tree-ssa-math-opts.c (do_shift_rotate): Zero bits out of type precision after operation. 2011-06-27 Kai Tietz * tree-ssa-math-opts.c (do_shift_rotate): Zero bits out of type precision after operation. (find_bswap): Take for limit value the integer auto- promotion into account. ChangeLog 2011-06-27 Kai Tietz * gcc.dg/optimize-bswapdi-2.c: New test. From-SVN: r175528 --- gcc/ChangeLog | 7 ++++++ gcc/testsuite/ChangeLog | 4 ++++ gcc/testsuite/gcc.dg/optimize-bswapdi-2.c | 26 +++++++++++++++++++++++ gcc/tree-ssa-math-opts.c | 16 ++++++++------ 4 files changed, 47 insertions(+), 6 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/optimize-bswapdi-2.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index ff7fe68d679..c107dfd225d 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,10 @@ +2011-06-27 Kai Tietz + + * tree-ssa-math-opts.c (do_shift_rotate): Zero bits + out of type precision after operation. + (find_bswap): Take for limit value the integer auto- + promotion into account. + 2011-06-27 Eric Botcazou * reorg.c (fill_simple_delay_slots): Use stop_search_p to stop the diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index c833b41a620..975409ec860 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2011-06-27 Kai Tietz + + * gcc.dg/optimize-bswapdi-2.c: New test. + 2011-06-27 Michael Hope Richard Sandiford diff --git a/gcc/testsuite/gcc.dg/optimize-bswapdi-2.c b/gcc/testsuite/gcc.dg/optimize-bswapdi-2.c new file mode 100644 index 00000000000..6e2821db990 --- /dev/null +++ b/gcc/testsuite/gcc.dg/optimize-bswapdi-2.c @@ -0,0 +1,26 @@ +/* { dg-do compile { target arm*-*-* alpha*-*-* ia64*-*-* x86_64-*-* s390x-*-* powerpc*-*-* rs6000-*-* } } */ +/* { dg-require-effective-target stdint_types } */ +/* { dg-require-effective-target lp64 } */ +/* { dg-options "-O2 -fdump-tree-bswap" } */ + +#include + +/* A variant via unsigned short. */ + +uint64_t +swap64_c (uint64_t x) +{ + uint16_t a0 = x >> 48; + uint16_t a1 = x >> 32; + uint16_t a2 = x >> 16; + uint16_t a3 = x; + + return ((uint64_t) (((a0 >> 8) & 0xff) | ((a0 << 8) & 0xff00))) + | ((uint64_t) (((a1 >> 8) & 0xff) | ((a1 << 8) & 0xff00)) << 16) + | ((uint64_t) (((a2 >> 8) & 0xff) | ((a2 << 8) & 0xff00)) << 32) + | ((uint64_t) (((a3 >> 8) & 0xff) | ((a3 << 8) & 0xff00)) << 48); +} + + +/* { dg-final { scan-tree-dump-times "64 bit bswap implementation found at" 1 "bswap" } } */ +/* { dg-final { cleanup-tree-dump "bswap" } } */ diff --git a/gcc/tree-ssa-math-opts.c b/gcc/tree-ssa-math-opts.c index bc7919a39ad..4da401827f4 100644 --- a/gcc/tree-ssa-math-opts.c +++ b/gcc/tree-ssa-math-opts.c @@ -1543,6 +1543,9 @@ do_shift_rotate (enum tree_code code, default: return false; } + /* Zero unused bits for size. */ + if (n->size < (int)sizeof (HOST_WIDEST_INT)) + n->n &= ((unsigned HOST_WIDEST_INT)1 << (n->size * BITS_PER_UNIT)) - 1; return true; } @@ -1740,15 +1743,16 @@ find_bswap (gimple stmt) struct symbolic_number n; tree source_expr; + int limit; /* The last parameter determines the depth search limit. It usually correlates directly to the number of bytes to be touched. We - increase that number by one here in order to also cover signed -> - unsigned conversions of the src operand as can be seen in - libgcc. */ - source_expr = find_bswap_1 (stmt, &n, - TREE_INT_CST_LOW ( - TYPE_SIZE_UNIT (gimple_expr_type (stmt))) + 1); + increase that number by three here in order to also + cover signed -> unsigned converions of the src operand as can be seen + in libgcc, and for initial shift/and operation of the src operand. */ + limit = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (gimple_expr_type (stmt))); + limit += 1 + (int) ceil_log2 ((unsigned HOST_WIDE_INT) limit); + source_expr = find_bswap_1 (stmt, &n, limit); if (!source_expr) return NULL_TREE; -- 2.30.2