diff options
Diffstat (limited to 'gcc/function.c')
| -rw-r--r-- | gcc/function.c | 41 |
1 files changed, 40 insertions, 1 deletions
diff --git a/gcc/function.c b/gcc/function.c index a93f48b..0df0b82 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -6150,6 +6150,36 @@ expand_dummy_function_end () current_function = 0; } +/* Emit CODE for each register of the return value. Useful values for + code are USE and CLOBBER. */ + +void +diddle_return_value (code) + enum rtx_code code; +{ + rtx return_reg = DECL_RTL (DECL_RESULT (current_function_decl)); + + if (return_reg) + { + if (GET_CODE (return_reg) == REG + && REGNO (return_reg) < FIRST_PSEUDO_REGISTER) + emit_insn (gen_rtx_fmt_e (code, VOIDmode, return_reg)); + else if (GET_CODE (return_reg) == PARALLEL) + { + int i; + + for (i = 0; i < XVECLEN (return_reg, 0); i++) + { + rtx x = XEXP (XVECEXP (return_reg, 0, i), 0); + + if (GET_CODE (x) == REG + && REGNO (x) < FIRST_PSEUDO_REGISTER) + emit_insn (gen_rtx_fmt_e (code, VOIDmode, x)); + } + } + } +} + /* Generate RTL for the end of the current function. FILENAME and LINE are the current position in the source file. @@ -6332,7 +6362,16 @@ expand_function_end (filename, line, end_bindings) structure returning. */ if (return_label) - emit_label (return_label); + { + /* Before the return label, clobber the return registers so that + they are not propogated live to the rest of the function. This + can only happen with functions that drop through; if there had + been a return statement, there would have either been a return + rtx, or a jump to the return label. */ + diddle_return_value (CLOBBER); + + emit_label (return_label); + } /* C++ uses this. */ if (end_bindings) |