diff options
Diffstat (limited to 'gcc/gimple-fold.c')
| -rw-r--r-- | gcc/gimple-fold.c | 50 |
1 files changed, 35 insertions, 15 deletions
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c index 4e3de95..72c5e43 100644 --- a/gcc/gimple-fold.c +++ b/gcc/gimple-fold.c @@ -700,7 +700,6 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, gimple *stmt = gsi_stmt (*gsi); tree lhs = gimple_call_lhs (stmt); tree len = gimple_call_arg (stmt, 2); - tree destvar, srcvar; location_t loc = gimple_location (stmt); /* If the LEN parameter is a constant zero or in range where @@ -741,7 +740,7 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, } else { - tree srctype, desttype; + tree srctype, desttype, destvar, srcvar, srcoff; unsigned int src_align, dest_align; tree off0; const char *tmp_str; @@ -991,7 +990,9 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, /* Choose between src and destination type for the access based on alignment, whether the access constitutes a register access and whether it may actually expose a declaration for SSA rewrite - or SRA decomposition. */ + or SRA decomposition. Also try to expose a string constant, we + might be able to concatenate several of them later into a single + string store. */ destvar = NULL_TREE; srcvar = NULL_TREE; if (TREE_CODE (dest) == ADDR_EXPR @@ -1008,7 +1009,16 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, && (is_gimple_reg_type (srctype) || dest_align >= TYPE_ALIGN (srctype))) srcvar = fold_build2 (MEM_REF, srctype, src, off0); - if (srcvar == NULL_TREE && destvar == NULL_TREE) + /* FIXME: Don't transform copies from strings with known original length. + As soon as strlenopt tests that rely on it for passing are adjusted, + this hack can be removed. */ + else if (gimple_call_alloca_for_var_p (stmt) + && (srcvar = string_constant (src, &srcoff, NULL, NULL)) + && integer_zerop (srcoff) + && tree_int_cst_equal (TYPE_SIZE_UNIT (TREE_TYPE (srcvar)), len) + && dest_align >= TYPE_ALIGN (TREE_TYPE (srcvar))) + srctype = TREE_TYPE (srcvar); + else return false; /* Now that we chose an access type express the other side in @@ -1071,19 +1081,29 @@ gimple_fold_builtin_memory_op (gimple_stmt_iterator *gsi, goto set_vop_and_replace; } - /* We get an aggregate copy. Use an unsigned char[] type to - perform the copying to preserve padding and to avoid any issues - with TREE_ADDRESSABLE types or float modes behavior on copying. */ - desttype = build_array_type_nelts (unsigned_char_type_node, - tree_to_uhwi (len)); - srctype = desttype; - if (src_align > TYPE_ALIGN (srctype)) - srctype = build_aligned_type (srctype, src_align); + /* We get an aggregate copy. If the source is a STRING_CST, then + directly use its type to perform the copy. */ + if (TREE_CODE (srcvar) == STRING_CST) + desttype = srctype; + + /* Or else, use an unsigned char[] type to perform the copy in order + to preserve padding and to avoid any issues with TREE_ADDRESSABLE + types or float modes behavior on copying. */ + else + { + desttype = build_array_type_nelts (unsigned_char_type_node, + tree_to_uhwi (len)); + srctype = desttype; + if (src_align > TYPE_ALIGN (srctype)) + srctype = build_aligned_type (srctype, src_align); + srcvar = fold_build2 (MEM_REF, srctype, src, off0); + } + if (dest_align > TYPE_ALIGN (desttype)) desttype = build_aligned_type (desttype, dest_align); - new_stmt - = gimple_build_assign (fold_build2 (MEM_REF, desttype, dest, off0), - fold_build2 (MEM_REF, srctype, src, off0)); + destvar = fold_build2 (MEM_REF, desttype, dest, off0); + new_stmt = gimple_build_assign (destvar, srcvar); + set_vop_and_replace: gimple_move_vops (new_stmt, stmt); if (!lhs) |