diff options
Diffstat (limited to 'gcc/function.c')
| -rw-r--r-- | gcc/function.c | 32 |
1 files changed, 24 insertions, 8 deletions
diff --git a/gcc/function.c b/gcc/function.c index 85a5d9f..69523c1 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -4937,18 +4937,34 @@ stack_protect_epilogue (void) tree guard_decl = targetm.stack_protect_guard (); rtx_code_label *label = gen_label_rtx (); rtx x, y; - rtx_insn *seq; + rtx_insn *seq = NULL; x = expand_normal (crtl->stack_protect_guard); - if (guard_decl) - y = expand_normal (guard_decl); + + if (targetm.have_stack_protect_combined_test () && guard_decl) + { + gcc_assert (DECL_P (guard_decl)); + y = DECL_RTL (guard_decl); + /* 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. */ + seq = targetm.gen_stack_protect_combined_test (x, y, label); + } else - y = const0_rtx; + { + 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); + } - /* 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)) + if (seq) emit_insn (seq); else emit_cmp_and_jump_insns (x, y, EQ, NULL_RTX, ptr_mode, 1, label); |