diff options
Diffstat (limited to 'gcc/reg-stack.c')
| -rw-r--r-- | gcc/reg-stack.c | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/gcc/reg-stack.c b/gcc/reg-stack.c index 25210f0c..1d9ea03 100644 --- a/gcc/reg-stack.c +++ b/gcc/reg-stack.c @@ -174,6 +174,7 @@ #include "reload.h" #include "tree-pass.h" #include "rtl-iter.h" +#include "function-abi.h" #ifdef STACK_REGS @@ -2368,6 +2369,18 @@ subst_asm_stack_regs (rtx_insn *insn, stack_ptr regstack) } } } + +/* Return true if a function call is allowed to alter some or all bits + of any stack reg. */ +static bool +callee_clobbers_any_stack_reg (const function_abi & callee_abi) +{ + for (unsigned regno = FIRST_STACK_REG; regno <= LAST_STACK_REG; regno++) + if (callee_abi.clobbers_at_least_part_of_reg_p (regno)) + return true; + return false; +} + /* Substitute stack hard reg numbers for stack virtual registers in INSN. Non-stack register numbers are not changed. REGSTACK is the @@ -2382,7 +2395,10 @@ subst_stack_regs (rtx_insn *insn, stack_ptr regstack) bool control_flow_insn_deleted = false; int i; - if (CALL_P (insn)) + /* If the target of the call doesn't clobber any stack registers, + Don't clear the arguments. */ + if (CALL_P (insn) + && callee_clobbers_any_stack_reg (insn_callee_abi (insn))) { int top = regstack->top; |