diff options
Diffstat (limited to 'gcc/builtins.c')
| -rw-r--r-- | gcc/builtins.c | 119 |
1 files changed, 88 insertions, 31 deletions
diff --git a/gcc/builtins.c b/gcc/builtins.c index fd6d0b8..0e5b834 100644 --- a/gcc/builtins.c +++ b/gcc/builtins.c @@ -51,6 +51,10 @@ along with GCC; see the file COPYING3. If not see #include "value-prof.h" #include "diagnostic.h" +#ifndef SLOW_UNALIGNED_ACCESS +#define SLOW_UNALIGNED_ACCESS(MODE, ALIGN) STRICT_ALIGNMENT +#endif + #ifndef PAD_VARARGS_DOWN #define PAD_VARARGS_DOWN BYTES_BIG_ENDIAN #endif @@ -8824,10 +8828,12 @@ fold_builtin_memory_op (tree dest, tree src, tree len, tree type, bool ignore, i else { tree srctype, desttype; + int src_align, dest_align; + if (endp == 3) { - int src_align = get_pointer_alignment (src, BIGGEST_ALIGNMENT); - int dest_align = get_pointer_alignment (dest, BIGGEST_ALIGNMENT); + src_align = get_pointer_alignment (src, BIGGEST_ALIGNMENT); + dest_align = get_pointer_alignment (dest, BIGGEST_ALIGNMENT); /* Both DEST and SRC must be pointer types. ??? This is what old code did. Is the testing for pointer types @@ -8862,44 +8868,95 @@ fold_builtin_memory_op (tree dest, tree src, tree len, tree type, bool ignore, i || !TYPE_SIZE_UNIT (srctype) || !TYPE_SIZE_UNIT (desttype) || TREE_CODE (TYPE_SIZE_UNIT (srctype)) != INTEGER_CST - || TREE_CODE (TYPE_SIZE_UNIT (desttype)) != INTEGER_CST - || !tree_int_cst_equal (TYPE_SIZE_UNIT (srctype), len) - || !tree_int_cst_equal (TYPE_SIZE_UNIT (desttype), len)) + || TREE_CODE (TYPE_SIZE_UNIT (desttype)) != INTEGER_CST) return NULL_TREE; - if (get_pointer_alignment (dest, BIGGEST_ALIGNMENT) - < (int) TYPE_ALIGN (desttype) - || (get_pointer_alignment (src, BIGGEST_ALIGNMENT) - < (int) TYPE_ALIGN (srctype))) + src_align = get_pointer_alignment (src, BIGGEST_ALIGNMENT); + dest_align = get_pointer_alignment (dest, BIGGEST_ALIGNMENT); + if (dest_align < (int) TYPE_ALIGN (desttype) + || src_align < (int) TYPE_ALIGN (srctype)) return NULL_TREE; if (!ignore) dest = builtin_save_expr (dest); - srcvar = build_fold_indirect_ref (src); - if (TREE_THIS_VOLATILE (srcvar)) - return NULL_TREE; - if (!tree_int_cst_equal (lang_hooks.expr_size (srcvar), len)) - return NULL_TREE; - /* With memcpy, it is possible to bypass aliasing rules, so without - this check i.e. execute/20060930-2.c would be misoptimized, because - it use conflicting alias set to hold argument for the memcpy call. - This check is probably unnecessary with -fno-strict-aliasing. - Similarly for destvar. See also PR29286. */ - if (!var_decl_component_p (srcvar) - /* Accept: memcpy (*char_var, "test", 1); that simplify - to char_var='t'; */ - || is_gimple_min_invariant (srcvar) - || readonly_data_expr (src)) + srcvar = NULL_TREE; + if (tree_int_cst_equal (TYPE_SIZE_UNIT (srctype), len)) + { + srcvar = build_fold_indirect_ref (src); + if (TREE_THIS_VOLATILE (srcvar)) + srcvar = NULL_TREE; + else if (!tree_int_cst_equal (lang_hooks.expr_size (srcvar), len)) + srcvar = NULL_TREE; + /* With memcpy, it is possible to bypass aliasing rules, so without + this check i.e. execute/20060930-2.c would be misoptimized, + because it use conflicting alias set to hold argument for the + memcpy call. This check is probably unnecessary with + -fno-strict-aliasing. Similarly for destvar. See also + PR29286. */ + else if (!var_decl_component_p (srcvar)) + srcvar = NULL_TREE; + } + + destvar = NULL_TREE; + if (tree_int_cst_equal (TYPE_SIZE_UNIT (desttype), len)) + { + destvar = build_fold_indirect_ref (dest); + if (TREE_THIS_VOLATILE (destvar)) + destvar = NULL_TREE; + else if (!tree_int_cst_equal (lang_hooks.expr_size (destvar), len)) + destvar = NULL_TREE; + else if (!var_decl_component_p (destvar)) + destvar = NULL_TREE; + } + + if (srcvar == NULL_TREE && destvar == NULL_TREE) return NULL_TREE; - destvar = build_fold_indirect_ref (dest); - if (TREE_THIS_VOLATILE (destvar)) - return NULL_TREE; - if (!tree_int_cst_equal (lang_hooks.expr_size (destvar), len)) - return NULL_TREE; - if (!var_decl_component_p (destvar)) - return NULL_TREE; + if (srcvar == NULL_TREE) + { + tree srcptype; + if (TREE_ADDRESSABLE (TREE_TYPE (destvar))) + return NULL_TREE; + + srctype = desttype; + if (src_align < (int) TYPE_ALIGN (srctype)) + { + if (AGGREGATE_TYPE_P (srctype) + || SLOW_UNALIGNED_ACCESS (TYPE_MODE (srctype), src_align)) + return NULL_TREE; + + srctype = build_variant_type_copy (srctype); + TYPE_ALIGN (srctype) = src_align; + TYPE_USER_ALIGN (srctype) = 1; + TYPE_PACKED (srctype) = 1; + } + srcptype = build_pointer_type_for_mode (srctype, ptr_mode, true); + src = fold_convert (srcptype, src); + srcvar = build_fold_indirect_ref (src); + } + else if (destvar == NULL_TREE) + { + tree destptype; + if (TREE_ADDRESSABLE (TREE_TYPE (srcvar))) + return NULL_TREE; + + desttype = srctype; + if (dest_align < (int) TYPE_ALIGN (desttype)) + { + if (AGGREGATE_TYPE_P (desttype) + || SLOW_UNALIGNED_ACCESS (TYPE_MODE (desttype), dest_align)) + return NULL_TREE; + + desttype = build_variant_type_copy (desttype); + TYPE_ALIGN (desttype) = dest_align; + TYPE_USER_ALIGN (desttype) = 1; + TYPE_PACKED (desttype) = 1; + } + destptype = build_pointer_type_for_mode (desttype, ptr_mode, true); + dest = fold_convert (destptype, dest); + destvar = build_fold_indirect_ref (dest); + } if (srctype == desttype || (gimple_in_ssa_p (cfun) |