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author | Bob Wilson <bob.wilson@acm.org> | 2007-11-02 00:45:34 +0000 |
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committer | Bob Wilson <bob.wilson@acm.org> | 2007-11-02 00:45:34 +0000 |
commit | 6a7eedfedcbe83b936a8be8abc489f0202205c7a (patch) | |
tree | 92eff89fd4932cf95b6e2d33b8bd5835947940fa /gas/config/tc-xtensa.c | |
parent | e4342ca3b861207ab18a2e240b0f675d5c6448fd (diff) | |
download | gdb-6a7eedfedcbe83b936a8be8abc489f0202205c7a.zip gdb-6a7eedfedcbe83b936a8be8abc489f0202205c7a.tar.gz gdb-6a7eedfedcbe83b936a8be8abc489f0202205c7a.tar.bz2 |
* config/tc-xtensa.c (xtensa_symbol_new_hook): New.
(xtensa_mark_difference_of_two_symbols): New.
(xtensa_post_relax_hook): Call xtensa_mark_difference_of_two_symbols.
* config/tc-xtensa.h (xtensa_symfield_type): Add next_expr_symbol.
(tc_symbol_new_hook): Define.
Diffstat (limited to 'gas/config/tc-xtensa.c')
-rw-r--r-- | gas/config/tc-xtensa.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/gas/config/tc-xtensa.c b/gas/config/tc-xtensa.c index 1882572..0738f27 100644 --- a/gas/config/tc-xtensa.c +++ b/gas/config/tc-xtensa.c @@ -5599,6 +5599,22 @@ xtensa_fix_adjustable (fixS *fixP) } +/* tc_symbol_new_hook */ + +symbolS *expr_symbols = NULL; + +void +xtensa_symbol_new_hook (symbolS *sym) +{ + if (S_GET_SEGMENT (sym) == expr_section) + { + symbol_get_tc (sym)->next_expr_symbol = expr_symbols; + expr_symbols = sym; + } +} + + + void md_apply_fix (fixS *fixP, valueT *valP, segT seg) { @@ -6943,6 +6959,7 @@ static void xtensa_cleanup_align_frags (void); static void xtensa_fix_target_frags (void); static void xtensa_mark_narrow_branches (void); static void xtensa_mark_zcl_first_insns (void); +static void xtensa_mark_difference_of_two_symbols (void); static void xtensa_fix_a0_b_retw_frags (void); static void xtensa_fix_b_j_loop_end_frags (void); static void xtensa_fix_close_loop_end_frags (void); @@ -7206,6 +7223,55 @@ xtensa_mark_zcl_first_insns (void) } +/* Some difference-of-symbols expressions make it out to the linker. Some + don't. If one does, then the linker can optimize between the two labels. + If it doesn't, then the linker shouldn't. */ + +static void +xtensa_mark_difference_of_two_symbols (void) +{ + symbolS *expr_sym; + + for (expr_sym = expr_symbols; expr_sym; + expr_sym = symbol_get_tc (expr_sym)->next_expr_symbol) + { + expressionS *expr = symbol_get_value_expression (expr_sym); + + if (expr->X_op == O_subtract) + { + symbolS *left = expr->X_add_symbol; + symbolS *right = expr->X_op_symbol; + + /* Difference of two symbols not in the same section + are handled with relocations in the linker. */ + if (S_GET_SEGMENT (left) == S_GET_SEGMENT (right)) + { + fragS *start; + fragS *end; + + if (symbol_get_frag (left)->fr_address + <= symbol_get_frag (right)->fr_address) + { + start = symbol_get_frag (left); + end = symbol_get_frag (right); + } + else + { + start = symbol_get_frag (right); + end = symbol_get_frag (left); + } + do + { + start->tc_frag_data.is_no_transform = 1; + start = start->fr_next; + } + while (start && start->fr_address < end->fr_address); + } + } + } +} + + /* Re-process all of the fragments looking to convert all of the RELAX_ADD_NOP_IF_A0_B_RETW. If the next instruction is a conditional branch or a retw/retw.n, convert this frag to one that @@ -10208,6 +10274,7 @@ xtensa_post_relax_hook (void) xtensa_find_unmarked_state_frags (); xtensa_mark_frags_for_org (); + xtensa_mark_difference_of_two_symbols (); xtensa_create_property_segments (get_frag_is_literal, NULL, |