diff options
Diffstat (limited to 'gcc/alias.c')
| -rw-r--r-- | gcc/alias.c | 44 |
1 files changed, 28 insertions, 16 deletions
diff --git a/gcc/alias.c b/gcc/alias.c index c115892..09c4530 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -103,7 +103,7 @@ static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, rtx, rtx, int (*) (rtx))); static int aliases_everything_p PARAMS ((rtx)); static int write_dependence_p PARAMS ((rtx, rtx, int)); -static int nonlocal_reference_p PARAMS ((rtx)); +static int nonlocal_mentioned_p PARAMS ((rtx)); /* Set up all info needed to perform alias analysis on memory references. */ @@ -1728,11 +1728,11 @@ output_dependence (mem, x) return write_dependence_p (mem, x, /*writep=*/1); } -/* Returns non-zero if X might refer to something which is not +/* Returns non-zero if X mentions something which is not local to the function and is not constant. */ static int -nonlocal_reference_p (x) +nonlocal_mentioned_p (x) rtx x; { rtx base; @@ -1792,13 +1792,7 @@ nonlocal_reference_p (x) return 1; case CALL: - /* Recursion introduces no additional considerations. */ - if (GET_CODE (XEXP (x, 0)) == MEM - && GET_CODE (XEXP (XEXP (x, 0), 0)) == SYMBOL_REF - && strcmp(XSTR (XEXP (XEXP (x, 0), 0), 0), - IDENTIFIER_POINTER ( - DECL_ASSEMBLER_NAME (current_function_decl))) == 0) - return 0; + /* Non-constant calls and recursion are not local. */ return 1; case MEM: @@ -1829,10 +1823,16 @@ nonlocal_reference_p (x) } return 1; + case UNSPEC_VOLATILE: case ASM_INPUT: - case ASM_OPERANDS: return 1; + case ASM_OPERANDS: + if (MEM_VOLATILE_P (x)) + return 1; + + /* FALLTHROUGH */ + default: break; } @@ -1847,14 +1847,14 @@ nonlocal_reference_p (x) { if (fmt[i] == 'e' && XEXP (x, i)) { - if (nonlocal_reference_p (XEXP (x, i))) + if (nonlocal_mentioned_p (XEXP (x, i))) return 1; } else if (fmt[i] == 'E') { register int j; for (j = 0; j < XVECLEN (x, i); j++) - if (nonlocal_reference_p (XVECEXP (x, i, j))) + if (nonlocal_mentioned_p (XVECEXP (x, i, j))) return 1; } } @@ -1869,22 +1869,34 @@ void mark_constant_function () { rtx insn; + int nonlocal_mentioned; if (TREE_PUBLIC (current_function_decl) || TREE_READONLY (current_function_decl) + || DECL_IS_PURE (current_function_decl) || TREE_THIS_VOLATILE (current_function_decl) || TYPE_MODE (TREE_TYPE (current_function_decl)) == VOIDmode) return; + nonlocal_mentioned = 0; + + init_alias_analysis (); + /* Determine if this is a constant function. */ for (insn = get_insns (); insn; insn = NEXT_INSN (insn)) - if (INSN_P (insn) && nonlocal_reference_p (insn)) - return; + if (INSN_P (insn) && nonlocal_mentioned_p (insn)) + { + nonlocal_mentioned = 1; + break; + } + + end_alias_analysis (); /* Mark the function. */ - TREE_READONLY (current_function_decl) = 1; + if (! nonlocal_mentioned) + TREE_READONLY (current_function_decl) = 1; } |