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Commit 76a7314d by Jakub Jelinek Committed by Jakub Jelinek
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re PR middle-end/78416 (wrong code for division by (u128)~INT64_MAX at -O0) 

	PR middle-end/78416
	* expmed.c (expand_divmod): Use wide_int for computation of
	op1_is_pow2.  Don't set it if op1 is 0.  Formatting fixes.
	Use size <= HOST_BITS_PER_WIDE_INT instead of
	HOST_BITS_PER_WIDE_INT >= size.

	* gcc.dg/torture/pr78416.c: New test.

From-SVN: r242690
parent 9b28cb6f
Showing with 57 additions and 23 deletions
gcc/ChangeLog
2016-11-22 Jakub Jelinek <jakub@redhat.com>
PR middle-end/78416
* expmed.c (expand_divmod): Use wide_int for computation of
op1_is_pow2. Don't set it if op1 is 0. Formatting fixes.
Use size <= HOST_BITS_PER_WIDE_INT instead of
HOST_BITS_PER_WIDE_INT >= size.
PR tree-optimization/78445
* tree-if-conv.c (tree_if_conversion): If any_pred_load_store or
any_complicated_phi, version loop even if flag_tree_loop_if_convert is
gcc/expmed.c
......@@ -3994,11 +3994,10 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
op1_is_constant = CONST_INT_P (op1);
if (op1_is_constant)
{
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)
|| (! unsignedp && EXACT_POWER_OF_2_OR_ZERO_P (-ext_op1))));
wide_int ext_op1 = rtx_mode_t (op1, mode);
op1_is_pow2 = (wi::popcount (ext_op1) == 1
|| (! unsignedp
&& wi::popcount (wi::neg (ext_op1)) == 1));
}
/*
......@@ -4079,11 +4078,10 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
not straightforward to generalize this. Maybe we should make an array
of possible modes in init_expmed? Save this for GCC 2.7. */
optab1 = ((op1_is_pow2 && op1 != const0_rtx)
optab1 = (op1_is_pow2
? (unsignedp ? lshr_optab : ashr_optab)
: (unsignedp ? udiv_optab : sdiv_optab));
optab2 = ((op1_is_pow2 && op1 != const0_rtx)
? optab1
optab2 = (op1_is_pow2 ? optab1
: (unsignedp ? udivmod_optab : sdivmod_optab));
for (compute_mode = mode; compute_mode != VOIDmode;
......@@ -4139,10 +4137,15 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
/* convert_modes may have placed op1 into a register, so we
must recompute the following. */
op1_is_constant = CONST_INT_P (op1);
op1_is_pow2 = (op1_is_constant
&& ((EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1))
|| (! unsignedp
&& EXACT_POWER_OF_2_OR_ZERO_P (-UINTVAL (op1))))));
if (op1_is_constant)
{
wide_int ext_op1 = rtx_mode_t (op1, compute_mode);
op1_is_pow2 = (wi::popcount (ext_op1) == 1
|| (! unsignedp
&& wi::popcount (wi::neg (ext_op1)) == 1));
}
else
op1_is_pow2 = 0;
}
/* If one of the operands is a volatile MEM, copy it into a register. */
......@@ -4182,10 +4185,10 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
unsigned HOST_WIDE_INT mh, ml;
int pre_shift, post_shift;
int dummy;
unsigned HOST_WIDE_INT d = (INTVAL (op1)
& GET_MODE_MASK (compute_mode));
wide_int wd = rtx_mode_t (op1, compute_mode);
unsigned HOST_WIDE_INT d = wd.to_uhwi ();
if (EXACT_POWER_OF_2_OR_ZERO_P (d))
if (wi::popcount (wd) == 1)
{
pre_shift = floor_log2 (d);
if (rem_flag)
......@@ -4325,7 +4328,7 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
else if (d == -1)
quotient = expand_unop (compute_mode, neg_optab, op0,
tquotient, 0);
else if (HOST_BITS_PER_WIDE_INT >= size
else if (size <= HOST_BITS_PER_WIDE_INT
&& abs_d == HOST_WIDE_INT_1U << (size - 1))
{
/* This case is not handled correctly below. */
......@@ -4335,6 +4338,7 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
goto fail1;
}
else if (EXACT_POWER_OF_2_OR_ZERO_P (d)
&& (size <= HOST_BITS_PER_WIDE_INT || d >= 0)
&& (rem_flag
? smod_pow2_cheap (speed, compute_mode)
: sdiv_pow2_cheap (speed, compute_mode))
......@@ -4348,7 +4352,9 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
compute_mode)
!= CODE_FOR_nothing)))
;
else if (EXACT_POWER_OF_2_OR_ZERO_P (abs_d))
else if (EXACT_POWER_OF_2_OR_ZERO_P (abs_d)
&& (size <= HOST_BITS_PER_WIDE_INT
|| abs_d != (unsigned HOST_WIDE_INT) d))
{
if (rem_flag)
{
......@@ -4483,7 +4489,7 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
case FLOOR_DIV_EXPR:
case FLOOR_MOD_EXPR:
/* We will come here only for signed operations. */
if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size)
if (op1_is_constant && size <= HOST_BITS_PER_WIDE_INT)
{
unsigned HOST_WIDE_INT mh, ml;
int pre_shift, lgup, post_shift;
......@@ -4552,9 +4558,8 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
op0, constm1_rtx), NULL_RTX);
t2 = expand_binop (compute_mode, ior_optab, op0, t1, NULL_RTX,
0, OPTAB_WIDEN);
nsign = expand_shift
(RSHIFT_EXPR, compute_mode, t2,
size - 1, NULL_RTX, 0);
nsign = expand_shift (RSHIFT_EXPR, compute_mode, t2,
size - 1, NULL_RTX, 0);
t3 = force_operand (gen_rtx_MINUS (compute_mode, t1, nsign),
NULL_RTX);
t4 = expand_divmod (0, TRUNC_DIV_EXPR, compute_mode, t3, op1,
......@@ -4663,7 +4668,10 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
case CEIL_MOD_EXPR:
if (unsignedp)
{
if (op1_is_constant && EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1)))
if (op1_is_constant
&& EXACT_POWER_OF_2_OR_ZERO_P (INTVAL (op1))
&& (size <= HOST_BITS_PER_WIDE_INT
|| INTVAL (op1) >= 0))
{
rtx t1, t2, t3;
unsigned HOST_WIDE_INT d = INTVAL (op1);
......@@ -4876,7 +4884,7 @@ expand_divmod (int rem_flag, enum tree_code code, machine_mode mode,
break;
case EXACT_DIV_EXPR:
if (op1_is_constant && HOST_BITS_PER_WIDE_INT >= size)
if (op1_is_constant && size <= HOST_BITS_PER_WIDE_INT)
{
HOST_WIDE_INT d = INTVAL (op1);
unsigned HOST_WIDE_INT ml;
......
gcc/testsuite/ChangeLog
2016-11-22 Jakub Jelinek <jakub@redhat.com>
PR middle-end/78416
* gcc.dg/torture/pr78416.c: New test.
PR tree-optimization/78445
* gcc.dg/pr78445.c: New test.
......
gcc/testsuite/gcc.dg/torture/pr78416.c 0 → 100644
/* PR middle-end/78416 */
/* { dg-do run { target int128 } } */
int
main ()
{
unsigned __int128 x;
x = 0xFFFFFFFFFFFFFFFFULL;
x /= ~0x7FFFFFFFFFFFFFFFLL;
if (x != 0)
__builtin_abort ();
x = ~0x7FFFFFFFFFFFFFFELL;
x /= ~0x7FFFFFFFFFFFFFFFLL;
if (x != 1)
__builtin_abort ();
return 0;
}
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