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riscv-gcc-1
Commit 0802d516 by Richard Kenner
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(simplify_rtx): Don't do anything with if_then_else_cond result if both one arm… 

(simplify_rtx): Don't do anything with if_then_else_cond result if both one arm and the input are a comparison.

(simplify_rtx): Don't do anything with if_then_else_cond
result if both one arm and the input are a comparison.
(simplify_{rtx,if_then_else,logical,shift_const}): Don't
test STORE_FLAG_VALUE with #if; properly test for just sign bit.
(num_sign_bit_copies, if_then_else_cond): Likewise.

From-SVN: r13551
parent 91674c37
Showing with 55 additions and 51 deletions
gcc/combine.c
......@@ -3138,7 +3138,12 @@ simplify_rtx (x, op0_mode, last, in_dest)
rtx cond, true, false;
cond = if_then_else_cond (x, &true, &false);
if (cond != 0)
if (cond != 0
/* If everything is a comparison, what we have is highly unlikely
to be simpler, so don't use it. */
&& ! (GET_RTX_CLASS (code) == '<'
&& (GET_RTX_CLASS (GET_CODE (true)) == '<'
|| GET_RTX_CLASS (GET_CODE (false)) == '<')))
{
rtx cop1 = const0_rtx;
enum rtx_code cond_code = simplify_comparison (NE, &cond, &cop1);
......@@ -3437,25 +3442,25 @@ simplify_rtx (x, op0_mode, last, in_dest)
return gen_lowpart_for_combine (mode, x);
}
#if STORE_FLAG_VALUE == -1
/* (not (comparison foo bar)) can be done by reversing the comparison
code if valid. */
if (GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == '<'
/* If STORE_FLAG_VALUE is -1, (not (comparison foo bar)) can be done by
reversing the comparison code if valid. */
if (STORE_FLAG_VALUE == -1
&& GET_RTX_CLASS (GET_CODE (XEXP (x, 0))) == '<'
&& reversible_comparison_p (XEXP (x, 0)))
return gen_rtx_combine (reverse_condition (GET_CODE (XEXP (x, 0))),
mode, XEXP (XEXP (x, 0), 0),
XEXP (XEXP (x, 0), 1));
/* (ashiftrt foo C) where C is the number of bits in FOO minus 1
is (lt foo (const_int 0)), so we can perform the above
simplification. */
is (lt foo (const_int 0)) if STORE_FLAG_VALUE is -1, so we can
perform the above simplification. */
if (XEXP (x, 1) == const1_rtx
if (STORE_FLAG_VALUE == -1
&& XEXP (x, 1) == const1_rtx
&& GET_CODE (XEXP (x, 0)) == ASHIFTRT
&& GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT
&& INTVAL (XEXP (XEXP (x, 0), 1)) == GET_MODE_BITSIZE (mode) - 1)
return gen_rtx_combine (GE, mode, XEXP (XEXP (x, 0), 0), const0_rtx);
#endif
/* Apply De Morgan's laws to reduce number of patterns for machines
with negating logical insns (and-not, nand, etc.). If result has
......@@ -3762,16 +3767,15 @@ simplify_rtx (x, op0_mode, last, in_dest)
break;
case MINUS:
#if STORE_FLAG_VALUE == 1
/* (minus 1 (comparison foo bar)) can be done by reversing the comparison
code if valid. */
if (XEXP (x, 0) == const1_rtx
/* If STORE_FLAG_VALUE is 1, (minus 1 (comparison foo bar)) can be done
by reversing the comparison code if valid. */
if (STORE_FLAG_VALUE == 1
&& XEXP (x, 0) == const1_rtx
&& GET_RTX_CLASS (GET_CODE (XEXP (x, 1))) == '<'
&& reversible_comparison_p (XEXP (x, 1)))
return gen_binary (reverse_condition (GET_CODE (XEXP (x, 1))),
mode, XEXP (XEXP (x, 1), 0),
XEXP (XEXP (x, 1), 1));
#endif
/* (minus <foo> (and <foo> (const_int -pow2))) becomes
(and <foo> (const_int pow2-1)) */
......@@ -3845,7 +3849,6 @@ simplify_rtx (x, op0_mode, last, in_dest)
/* Simplify our comparison, if possible. */
new_code = simplify_comparison (code, &op0, &op1);
#if STORE_FLAG_VALUE == 1
/* If STORE_FLAG_VALUE is 1, we can convert (ne x 0) to simply X
if only the low-order bit is possibly nonzero in X (such as when
X is a ZERO_EXTRACT of one bit). Similarly, we can convert EQ to
......@@ -3858,13 +3861,14 @@ simplify_rtx (x, op0_mode, last, in_dest)
ZERO_EXTRACT is indeed appropriate, it will be placed back by
the call to make_compound_operation in the SET case. */
if (new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& nonzero_bits (op0, mode) == 1)
if (STORE_FLAG_VALUE == 1
&& new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx && nonzero_bits (op0, mode) == 1)
return gen_lowpart_for_combine (mode,
expand_compound_operation (op0));
else if (new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
else if (STORE_FLAG_VALUE == 1
&& new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& (num_sign_bit_copies (op0, mode)
== GET_MODE_BITSIZE (mode)))
......@@ -3874,7 +3878,8 @@ simplify_rtx (x, op0_mode, last, in_dest)
gen_lowpart_for_combine (mode, op0));
}
else if (new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
else if (STORE_FLAG_VALUE == 1
&& new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& nonzero_bits (op0, mode) == 1)
{
......@@ -3884,7 +3889,8 @@ simplify_rtx (x, op0_mode, last, in_dest)
const1_rtx);
}
else if (new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
else if (STORE_FLAG_VALUE == 1
&& new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& (num_sign_bit_copies (op0, mode)
== GET_MODE_BITSIZE (mode)))
......@@ -3892,19 +3898,19 @@ simplify_rtx (x, op0_mode, last, in_dest)
op0 = expand_compound_operation (op0);
return plus_constant (gen_lowpart_for_combine (mode, op0), 1);
}
#endif
#if STORE_FLAG_VALUE == -1
/* If STORE_FLAG_VALUE is -1, we have cases similar to
those above. */
if (new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
if (STORE_FLAG_VALUE == -1
&& new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& (num_sign_bit_copies (op0, mode)
== GET_MODE_BITSIZE (mode)))
return gen_lowpart_for_combine (mode,
expand_compound_operation (op0));
else if (new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
else if (STORE_FLAG_VALUE == -1
&& new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& nonzero_bits (op0, mode) == 1)
{
......@@ -3913,7 +3919,8 @@ simplify_rtx (x, op0_mode, last, in_dest)
gen_lowpart_for_combine (mode, op0));
}
else if (new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
else if (STORE_FLAG_VALUE == -1
&& new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& (num_sign_bit_copies (op0, mode)
== GET_MODE_BITSIZE (mode)))
......@@ -3924,14 +3931,14 @@ simplify_rtx (x, op0_mode, last, in_dest)
}
/* If X is 0/1, (eq X 0) is X-1. */
else if (new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
else if (STORE_FLAG_VALUE == -1
&& new_code == EQ && GET_MODE_CLASS (mode) == MODE_INT
&& op1 == const0_rtx
&& nonzero_bits (op0, mode) == 1)
{
op0 = expand_compound_operation (op0);
return plus_constant (gen_lowpart_for_combine (mode, op0), -1);
}
#endif
/* If STORE_FLAG_VALUE says to just test the sign bit and X has just
one bit that might be nonzero, we can convert (ne x 0) to
......@@ -3940,7 +3947,7 @@ simplify_rtx (x, op0_mode, last, in_dest)
going to test the sign bit. */
if (new_code == NE && GET_MODE_CLASS (mode) == MODE_INT
&& GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& (STORE_FLAG_VALUE
&& ((STORE_FLAG_VALUE & GET_MODE_MASK (mode))
== (HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))
&& op1 == const0_rtx
&& mode == GET_MODE (op0)
......@@ -4215,16 +4222,15 @@ simplify_if_then_else (x)
return gen_binary (UMIN, mode, true, false);
}
#if STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1
/* If we have (if_then_else COND (OP Z C1) Z) and OP is an identity when its
second operand is zero, this can be done as (OP Z (mult COND C2)) where
C2 = C1 * STORE_FLAG_VALUE. Similarly if OP has an outer ZERO_EXTEND or
SIGN_EXTEND as long as Z is already extended (so we don't destroy it).
We can do this kind of thing in some cases when STORE_FLAG_VALUE is
neither of the above, but it isn't worth checking for. */
neither 1 or -1, but it isn't worth checking for. */
if (comparison_p && mode != VOIDmode && ! side_effects_p (x))
if ((STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1)
&& comparison_p && mode != VOIDmode && ! side_effects_p (x))
{
rtx t = make_compound_operation (true, SET);
rtx f = make_compound_operation (false, SET);
......@@ -4333,7 +4339,6 @@ simplify_if_then_else (x)
return temp;
}
}
#endif
/* If we have (if_then_else (ne A 0) C1 0) and either A is known to be 0 or
1 and C1 is a single bit or A is known to be 0 or -1 and C1 is the
......@@ -4874,10 +4879,10 @@ simplify_logical (x, last)
gen_unary (NOT, mode, mode, XEXP (op0, 1)),
op1);
#if STORE_FLAG_VALUE == 1
/* (xor (comparison foo bar) (const_int 1)) can become the reversed
comparison. */
if (op1 == const1_rtx
comparison if STORE_FLAG_VALUE is 1. */
if (STORE_FLAG_VALUE == 1
&& op1 == const1_rtx
&& GET_RTX_CLASS (GET_CODE (op0)) == '<'
&& reversible_comparison_p (op0))
return gen_rtx_combine (reverse_condition (GET_CODE (op0)),
......@@ -4885,19 +4890,19 @@ simplify_logical (x, last)
/* (lshiftrt foo C) where C is the number of bits in FOO minus 1
is (lt foo (const_int 0)), so we can perform the above
simplification. */
simplification if STORE_FLAG_VALUE is 1. */
if (op1 == const1_rtx
if (STORE_FLAG_VALUE == 1
&& op1 == const1_rtx
&& GET_CODE (op0) == LSHIFTRT
&& GET_CODE (XEXP (op0, 1)) == CONST_INT
&& INTVAL (XEXP (op0, 1)) == GET_MODE_BITSIZE (mode) - 1)
return gen_rtx_combine (GE, mode, XEXP (op0, 0), const0_rtx);
#endif
/* (xor (comparison foo bar) (const_int sign-bit))
when STORE_FLAG_VALUE is the sign bit. */
if (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_WIDE_INT
&& (STORE_FLAG_VALUE
&& ((STORE_FLAG_VALUE & GET_MODE_MASK (mode))
== (HOST_WIDE_INT) 1 << (GET_MODE_BITSIZE (mode) - 1))
&& op1 == const_true_rtx
&& GET_RTX_CLASS (GET_CODE (op0)) == '<'
......@@ -6483,12 +6488,12 @@ if_then_else_cond (x, ptrue, pfalse)
return cond0 ? cond0 : cond1;
}
#if STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1
/* See if we have PLUS, IOR, XOR, MINUS or UMAX, where one of the
operands is zero when the other is non-zero, and vice-versa. */
operands is zero when the other is non-zero, and vice-versa,
and STORE_FLAG_VALUE is 1 or -1. */
if ((code == PLUS || code == IOR || code == XOR || code == MINUS
if ((STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1)
&& (code == PLUS || code == IOR || code == XOR || code == MINUS
|| code == UMAX)
&& GET_CODE (XEXP (x, 0)) == MULT && GET_CODE (XEXP (x, 1)) == MULT)
{
......@@ -6521,7 +6526,8 @@ if_then_else_cond (x, ptrue, pfalse)
/* Similarly for MULT, AND and UMIN, execpt that for these the result
is always zero. */
if ((code == MULT || code == AND || code == UMIN)
if ((STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1)
&& (code == MULT || code == AND || code == UMIN)
&& GET_CODE (XEXP (x, 0)) == MULT && GET_CODE (XEXP (x, 1)) == MULT)
{
cond0 = XEXP (XEXP (x, 0), 0);
......@@ -6543,7 +6549,6 @@ if_then_else_cond (x, ptrue, pfalse)
return cond0;
}
}
#endif
}
else if (code == IF_THEN_ELSE)
......@@ -7773,11 +7778,10 @@ num_sign_bit_copies (x, mode)
num1 = num_sign_bit_copies (XEXP (x, 2), mode);
return MIN (num0, num1);
#if STORE_FLAG_VALUE == -1
case EQ: case NE: case GE: case GT: case LE: case LT:
case GEU: case GTU: case LEU: case LTU:
if (STORE_FLAG_VALUE == -1)
return bitwidth;
#endif
}
/* If we haven't been able to figure it out by one of the above rules,
......@@ -8545,9 +8549,9 @@ simplify_shift_const (x, code, result_mode, varop, count)
STORE_FLAG_VALUE of 1 or logical with STORE_FLAG_VALUE == -1,
we have a (neg (gt X 0)) operation. */
if (GET_CODE (XEXP (varop, 0)) == ASHIFTRT
if ((STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1)
&& GET_CODE (XEXP (varop, 0)) == ASHIFTRT
&& count == GET_MODE_BITSIZE (GET_MODE (varop)) - 1
&& (STORE_FLAG_VALUE == 1 || STORE_FLAG_VALUE == -1)
&& (code == LSHIFTRT || code == ASHIFTRT)
&& GET_CODE (XEXP (XEXP (varop, 0), 1)) == CONST_INT
&& INTVAL (XEXP (XEXP (varop, 0), 1)) == count
......
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