diff options
Diffstat (limited to 'gcc/tree-ssa-operands.c')
| -rw-r--r-- | gcc/tree-ssa-operands.c | 99 |
1 files changed, 67 insertions, 32 deletions
diff --git a/gcc/tree-ssa-operands.c b/gcc/tree-ssa-operands.c index f4eb109..609fa0f 100644 --- a/gcc/tree-ssa-operands.c +++ b/gcc/tree-ssa-operands.c @@ -33,6 +33,7 @@ Boston, MA 02110-1301, USA. */ #include "timevar.h" #include "toplev.h" #include "langhooks.h" +#include "ipa-reference.h" /* This file contains the code required to manage the operands cache of the SSA optimizer. For every stmt, we maintain an operand cache in the stmt @@ -156,7 +157,7 @@ static inline void append_def (tree *); static inline void append_use (tree *); static void append_v_may_def (tree); static void append_v_must_def (tree); -static void add_call_clobber_ops (tree); +static void add_call_clobber_ops (tree, tree); static void add_call_read_ops (tree); static void add_stmt_operand (tree *, stmt_ann_t, int); static void build_ssa_operands (tree stmt); @@ -1727,7 +1728,7 @@ get_call_expr_operands (tree stmt, tree expr) there is no point in recording that. */ if (TREE_SIDE_EFFECTS (expr) && !(call_flags & (ECF_PURE | ECF_CONST | ECF_NORETURN))) - add_call_clobber_ops (stmt); + add_call_clobber_ops (stmt, get_callee_fndecl (expr)); else if (!(call_flags & ECF_CONST)) add_call_read_ops (stmt); } @@ -1944,7 +1945,7 @@ add_to_addressable_set (tree ref, bitmap *addresses_taken) clobbered variables in the function. */ static void -add_call_clobber_ops (tree stmt) +add_call_clobber_ops (tree stmt, tree callee) { int i; unsigned u; @@ -1952,6 +1953,7 @@ add_call_clobber_ops (tree stmt) bitmap_iterator bi; stmt_ann_t s_ann = stmt_ann (stmt); struct stmt_ann_d empty_ann; + bitmap not_read_b, not_written_b; /* Functions that are not const, pure or never return may clobber call-clobbered variables. */ @@ -1966,8 +1968,22 @@ add_call_clobber_ops (tree stmt) return; } + /* FIXME - if we have better information from the static vars + analysis, we need to make the cache call site specific. This way + we can have the performance benefits even if we are doing good + optimization. */ + + /* Get info for local and module level statics. There is a bit + set for each static if the call being processed does not read + or write that variable. */ + + not_read_b = callee ? ipa_reference_get_not_read_global (callee) : NULL; + not_written_b = callee ? ipa_reference_get_not_written_global (callee) : NULL; + /* If cache is valid, copy the elements into the build vectors. */ - if (ssa_call_clobbered_cache_valid) + if (ssa_call_clobbered_cache_valid + && (!not_read_b || bitmap_empty_p (not_read_b)) + && (!not_written_b || bitmap_empty_p (not_written_b))) { /* Process the caches in reverse order so we are always inserting at the head of the list. */ @@ -2002,43 +2018,62 @@ add_call_clobber_ops (tree stmt) if (unmodifiable_var_p (var)) add_stmt_operand (&var, &empty_ann, opf_none); else - add_stmt_operand (&var, &empty_ann, opf_is_def | opf_non_specific); + { + bool not_read + = not_read_b ? bitmap_bit_p (not_read_b, u) : false; + bool not_written + = not_written_b ? bitmap_bit_p (not_written_b, u) : false; + + if ((TREE_READONLY (var) + && (TREE_STATIC (var) || DECL_EXTERNAL (var))) + || not_written) + { + if (!not_read) + add_stmt_operand (&var, &empty_ann, opf_none); + } + else + add_stmt_operand (&var, &empty_ann, opf_is_def); + } } - clobbered_aliased_loads = empty_ann.makes_aliased_loads; - clobbered_aliased_stores = empty_ann.makes_aliased_stores; - - /* Set the flags for a stmt's annotation. */ - if (s_ann) + if ((!not_read_b || bitmap_empty_p (not_read_b)) + && (!not_written_b || bitmap_empty_p (not_written_b))) { - s_ann->makes_aliased_loads = empty_ann.makes_aliased_loads; - s_ann->makes_aliased_stores = empty_ann.makes_aliased_stores; - } + clobbered_aliased_loads = empty_ann.makes_aliased_loads; + clobbered_aliased_stores = empty_ann.makes_aliased_stores; - /* Prepare empty cache vectors. */ - VEC_truncate (tree, clobbered_vuses, 0); - VEC_truncate (tree, clobbered_v_may_defs, 0); + /* Set the flags for a stmt's annotation. */ + if (s_ann) + { + s_ann->makes_aliased_loads = empty_ann.makes_aliased_loads; + s_ann->makes_aliased_stores = empty_ann.makes_aliased_stores; + } - /* Now fill the clobbered cache with the values that have been found. */ - for (i = opbuild_first (&build_vuses); - i != OPBUILD_LAST; - i = opbuild_next (&build_vuses, i)) - VEC_safe_push (tree, heap, clobbered_vuses, - opbuild_elem_virtual (&build_vuses, i)); + /* Prepare empty cache vectors. */ + VEC_truncate (tree, clobbered_vuses, 0); + VEC_truncate (tree, clobbered_v_may_defs, 0); - gcc_assert (opbuild_num_elems (&build_vuses) - == VEC_length (tree, clobbered_vuses)); + /* Now fill the clobbered cache with the values that have been found. */ + for (i = opbuild_first (&build_vuses); + i != OPBUILD_LAST; + i = opbuild_next (&build_vuses, i)) + VEC_safe_push (tree, heap, clobbered_vuses, + opbuild_elem_virtual (&build_vuses, i)); - for (i = opbuild_first (&build_v_may_defs); - i != OPBUILD_LAST; - i = opbuild_next (&build_v_may_defs, i)) - VEC_safe_push (tree, heap, clobbered_v_may_defs, - opbuild_elem_virtual (&build_v_may_defs, i)); + gcc_assert (opbuild_num_elems (&build_vuses) + == VEC_length (tree, clobbered_vuses)); + + for (i = opbuild_first (&build_v_may_defs); + i != OPBUILD_LAST; + i = opbuild_next (&build_v_may_defs, i)) + VEC_safe_push (tree, heap, clobbered_v_may_defs, + opbuild_elem_virtual (&build_v_may_defs, i)); - gcc_assert (opbuild_num_elems (&build_v_may_defs) - == VEC_length (tree, clobbered_v_may_defs)); + gcc_assert (opbuild_num_elems (&build_v_may_defs) + == VEC_length (tree, clobbered_v_may_defs)); - ssa_call_clobbered_cache_valid = true; + ssa_call_clobbered_cache_valid = true; + } } |