diff options
Diffstat (limited to 'gcc/rtlanal.c')
| -rw-r--r-- | gcc/rtlanal.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c index 7c7731b..d8c9fb8 100644 --- a/gcc/rtlanal.c +++ b/gcc/rtlanal.c @@ -2033,16 +2033,25 @@ side_effects_p (rtx x) return 0; } -/* Return nonzero if evaluating rtx X might cause a trap. UNALIGNED_MEMS - controls whether nonzero is returned for unaligned memory accesses on - strict alignment machines. */ +enum may_trap_p_flags +{ + MTP_UNALIGNED_MEMS = 1, + MTP_AFTER_MOVE = 2 +}; +/* Return nonzero if evaluating rtx X might cause a trap. + (FLAGS & MTP_UNALIGNED_MEMS) controls whether nonzero is returned for + unaligned memory accesses on strict alignment machines. If + (FLAGS & AFTER_MOVE) is true, returns nonzero even in case the expression + cannot trap at its current location, but it might become trapping if moved + elsewhere. */ static int -may_trap_p_1 (rtx x, bool unaligned_mems) +may_trap_p_1 (rtx x, unsigned flags) { int i; enum rtx_code code; const char *fmt; + bool unaligned_mems = (flags & MTP_UNALIGNED_MEMS) != 0; if (x == 0) return 0; @@ -2072,7 +2081,11 @@ may_trap_p_1 (rtx x, bool unaligned_mems) /* Memory ref can trap unless it's a static var or a stack slot. */ case MEM: - if (MEM_NOTRAP_P (x) + if (/* MEM_NOTRAP_P only relates to the actual position of the memory + reference; moving it out of condition might cause its address + become invalid. */ + !(flags & MTP_AFTER_MOVE) + && MEM_NOTRAP_P (x) && (!STRICT_ALIGNMENT || !unaligned_mems)) return 0; return @@ -2152,14 +2165,14 @@ may_trap_p_1 (rtx x, bool unaligned_mems) { if (fmt[i] == 'e') { - if (may_trap_p_1 (XEXP (x, i), unaligned_mems)) + if (may_trap_p_1 (XEXP (x, i), flags)) return 1; } else if (fmt[i] == 'E') { int j; for (j = 0; j < XVECLEN (x, i); j++) - if (may_trap_p_1 (XVECEXP (x, i, j), unaligned_mems)) + if (may_trap_p_1 (XVECEXP (x, i, j), flags)) return 1; } } @@ -2171,7 +2184,16 @@ may_trap_p_1 (rtx x, bool unaligned_mems) int may_trap_p (rtx x) { - return may_trap_p_1 (x, false); + return may_trap_p_1 (x, 0); +} + +/* Return nonzero if evaluating rtx X might cause a trap, when the expression + is moved from its current location by some optimization. */ + +int +may_trap_after_code_motion_p (rtx x) +{ + return may_trap_p_1 (x, MTP_AFTER_MOVE); } /* Same as above, but additionally return non-zero if evaluating rtx X might @@ -2217,7 +2239,7 @@ may_trap_p (rtx x) int may_trap_or_fault_p (rtx x) { - return may_trap_p_1 (x, true); + return may_trap_p_1 (x, MTP_UNALIGNED_MEMS); } /* Return nonzero if X contains a comparison that is not either EQ or NE, |