diff options
Diffstat (limited to 'gcc/optabs.c')
| -rw-r--r-- | gcc/optabs.c | 22 |
1 files changed, 21 insertions, 1 deletions
diff --git a/gcc/optabs.c b/gcc/optabs.c index 319a19f..db0a078 100644 --- a/gcc/optabs.c +++ b/gcc/optabs.c @@ -2263,10 +2263,29 @@ expand_abs (mode, op0, target, safe) if (temp != 0) return temp; + /* If we have a MAX insn, we can do this as MAX (x, -x). */ + if (smax_optab->handlers[(int) mode].insn_code != CODE_FOR_nothing) + { + rtx last = get_last_insn (); + + temp = expand_unop (mode, neg_optab, op0, NULL_RTX, 0); + if (temp != 0) + temp = expand_binop (mode, smax_optab, op0, temp, target, 0, + OPTAB_WIDEN); + + if (temp != 0) + return temp; + + delete_insns_since (last); + } + /* If this machine has expensive jumps, we can do integer absolute value of X as (((signed) x >> (W-1)) ^ x) - ((signed) x >> (W-1)), - where W is the width of MODE. */ + where W is the width of MODE. But don't do this if the machine has + conditional arithmetic since the branches will be converted into + a conditional negation insn. */ +#ifndef HAVE_conditional_arithmetic if (GET_MODE_CLASS (mode) == MODE_INT && BRANCH_COST >= 2) { rtx extended = expand_shift (RSHIFT_EXPR, mode, op0, @@ -2282,6 +2301,7 @@ expand_abs (mode, op0, target, safe) if (temp != 0) return temp; } +#endif /* If that does not win, use conditional jump and negate. */ |