diff options
Diffstat (limited to 'gcc/function.c')
| -rw-r--r-- | gcc/function.c | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/gcc/function.c b/gcc/function.c index dee303c..a95d2f8 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -4893,20 +4893,33 @@ stack_protect_epilogue (void) rtx_code_label *label = gen_label_rtx (); rtx x, y; rtx_insn *seq; + struct expand_operand ops[3]; x = expand_normal (crtl->stack_protect_guard); - if (guard_decl) - y = expand_normal (guard_decl); - else - y = const0_rtx; - - /* Allow the target to compare Y with X without leaking either into - a register. */ - if (targetm.have_stack_protect_test () - && ((seq = targetm.gen_stack_protect_test (x, y, label)) != NULL_RTX)) - emit_insn (seq); - else - emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label); + create_fixed_operand (&ops[0], x); + create_fixed_operand (&ops[1], DECL_RTL (guard_decl)); + create_fixed_operand (&ops[2], label); + /* Allow the target to compute address of Y and compare it with X without + leaking Y into a register. This combined address + compare pattern allows + the target to prevent spilling of any intermediate results by splitting + it after register allocator. */ + if (!maybe_expand_jump_insn (targetm.code_for_stack_protect_combined_test, + 3, ops)) + { + if (guard_decl) + y = expand_normal (guard_decl); + else + y = const0_rtx; + + /* Allow the target to compare Y with X without leaking either into + a register. */ + if (targetm.have_stack_protect_test () + && ((seq = targetm.gen_stack_protect_test (x, y, label)) + != NULL_RTX)) + emit_insn (seq); + else + emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label); + } /* The noreturn predictor has been moved to the tree level. The rtl-level predictors estimate this branch about 20%, which isn't enough to get |