diff options
Diffstat (limited to 'gcc/expmed.c')
| -rw-r--r-- | gcc/expmed.c | 35 |
1 files changed, 25 insertions, 10 deletions
diff --git a/gcc/expmed.c b/gcc/expmed.c index 954a360c7b2..d66c6e667fb 100644 --- a/gcc/expmed.c +++ b/gcc/expmed.c @@ -64,7 +64,8 @@ static rtx expand_smod_pow2 (enum machine_mode, rtx, HOST_WIDE_INT); static rtx expand_sdiv_pow2 (enum machine_mode, rtx, HOST_WIDE_INT); /* Test whether a value is zero of a power of two. */ -#define EXACT_POWER_OF_2_OR_ZERO_P(x) (((x) & ((x) - 1)) == 0) +#define EXACT_POWER_OF_2_OR_ZERO_P(x) \ + (((x) & ((x) - (unsigned HOST_WIDE_INT) 1)) == 0) struct init_expmed_rtl { @@ -3079,7 +3080,10 @@ expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, /* If we are multiplying in DImode, it may still be a win to try to work with shifts and adds. */ if (CONST_DOUBLE_HIGH (scalar_op1) == 0 - && CONST_DOUBLE_LOW (scalar_op1) > 0) + && (CONST_DOUBLE_LOW (scalar_op1) > 0 + || (CONST_DOUBLE_LOW (scalar_op1) < 0 + && EXACT_POWER_OF_2_OR_ZERO_P + (CONST_DOUBLE_LOW (scalar_op1))))) { coeff = CONST_DOUBLE_LOW (scalar_op1); is_neg = false; @@ -3109,7 +3113,8 @@ expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, use synth_mult. */ /* Special case powers of two. */ - if (EXACT_POWER_OF_2_OR_ZERO_P (coeff)) + if (EXACT_POWER_OF_2_OR_ZERO_P (coeff) + && !(is_neg && mode_bitsize > HOST_BITS_PER_WIDE_INT)) return expand_shift (LSHIFT_EXPR, mode, op0, floor_log2 (coeff), target, unsignedp); @@ -3124,13 +3129,24 @@ expand_mult (enum machine_mode mode, rtx op0, rtx op1, rtx target, result is interpreted as an unsigned coefficient. Exclude cost of op0 from max_cost to match the cost calculation of the synth_mult. */ + coeff = -(unsigned HOST_WIDE_INT) coeff; max_cost = (set_src_cost (gen_rtx_MULT (mode, fake_reg, op1), speed) - neg_cost(speed, mode)); - if (max_cost > 0 - && choose_mult_variant (mode, -coeff, &algorithm, - &variant, max_cost)) + if (max_cost <= 0) + goto skip_synth; + + /* Special case powers of two. */ + if (EXACT_POWER_OF_2_OR_ZERO_P (coeff)) + { + rtx temp = expand_shift (LSHIFT_EXPR, mode, op0, + floor_log2 (coeff), target, unsignedp); + return expand_unop (mode, neg_optab, temp, target, 0); + } + + if (choose_mult_variant (mode, coeff, &algorithm, &variant, + max_cost)) { - rtx temp = expand_mult_const (mode, op0, -coeff, NULL_RTX, + rtx temp = expand_mult_const (mode, op0, coeff, NULL_RTX, &algorithm, variant); return expand_unop (mode, neg_optab, temp, target, 0); } @@ -3813,13 +3829,12 @@ expand_divmod (int rem_flag, enum tree_code code, enum machine_mode mode, int op1_is_constant, op1_is_pow2 = 0; int max_cost, extra_cost; static HOST_WIDE_INT last_div_const = 0; - static HOST_WIDE_INT ext_op1; bool speed = optimize_insn_for_speed_p (); op1_is_constant = CONST_INT_P (op1); if (op1_is_constant) { - ext_op1 = INTVAL (op1); + unsigned HOST_WIDE_INT ext_op1 = UINTVAL (op1); if (unsignedp) ext_op1 &= GET_MODE_MASK (mode); op1_is_pow2 = ((EXACT_POWER_OF_2_OR_ZERO_P (ext_op1) @@ -3967,7 +3982,7 @@ expand_divmod (int rem_flag, enum tree_code code, enum machine_mode mode, op1_is_pow2 = (op1_is_constant && ((EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1)) || (! unsignedp - && EXACT_POWER_OF_2_OR_ZERO_P (-INTVAL (op1)))))) ; + && EXACT_POWER_OF_2_OR_ZERO_P (-UINTVAL (op1)))))); } /* If one of the operands is a volatile MEM, copy it into a register. */ |