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(expand_expr, case COND_EXPR): Add additional cases to "singleton"

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cases.

From-SVN: r13372
This commit is contained in:
Richard Kenner 1997-01-04 22:03:27 -05:00
parent c7554b2898
commit ac01eace31
1 changed files with 46 additions and 11 deletions
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57
gcc/expr.c
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@ -1,5 +1,5 @@
/* Convert tree expression to rtl instructions, for GNU compiler.
Copyright (C) 1988, 92, 93, 94, 95, 1996 Free Software Foundation, Inc.
Copyright (C) 1988, 92, 93, 94, 95, 96, 1997 Free Software Foundation, Inc.
This file is part of GNU CC.
@ -6459,6 +6459,31 @@ expand_expr (exp, target, tmode, modifier)
VOIDmode, 0);
case COND_EXPR:
/* If we would have a "singleton" (see below) were it not for a
conversion in each arm, bring that conversion back out. */
if (TREE_CODE (TREE_OPERAND (exp, 1)) == NOP_EXPR
&& TREE_CODE (TREE_OPERAND (exp, 2)) == NOP_EXPR
&& (TREE_TYPE (TREE_OPERAND (TREE_OPERAND (exp, 1), 0))
== TREE_TYPE (TREE_OPERAND (TREE_OPERAND (exp, 2), 0))))
{
tree true = TREE_OPERAND (TREE_OPERAND (exp, 1), 0);
tree false = TREE_OPERAND (TREE_OPERAND (exp, 2), 0);
if ((TREE_CODE_CLASS (TREE_CODE (true)) == '2'
&& operand_equal_p (false, TREE_OPERAND (true, 0), 0))
|| (TREE_CODE_CLASS (TREE_CODE (false)) == '2'
&& operand_equal_p (true, TREE_OPERAND (false, 0), 0))
|| (TREE_CODE_CLASS (TREE_CODE (true)) == '1'
&& operand_equal_p (false, TREE_OPERAND (true, 0), 0))
|| (TREE_CODE_CLASS (TREE_CODE (false)) == '1'
&& operand_equal_p (true, TREE_OPERAND (false, 0), 0)))
return expand_expr (build1 (NOP_EXPR, type,
build (COND_EXPR, TREE_TYPE (true),
TREE_OPERAND (exp, 0),
true, false)),
target, tmode, modifier);
}
{
rtx flag = NULL_RTX;
tree left_cleanups = NULL_TREE;
@ -6506,11 +6531,11 @@ expand_expr (exp, target, tmode, modifier)
return target;
}
/* Check for X ? A + B : A. If we have this, we can copy
A to the output and conditionally add B. Similarly for unary
operations. Don't do this if X has side-effects because
those side effects might affect A or B and the "?" operation is
a sequence point in ANSI. (We test for side effects later.) */
/* Check for X ? A + B : A. If we have this, we can copy A to the
output and conditionally add B. Similarly for unary operations.
Don't do this if X has side-effects because those side effects
might affect A or B and the "?" operation is a sequence point in
ANSI. (operand_equal_p tests for side effects.) */
if (TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, 1))) == '2'
&& operand_equal_p (TREE_OPERAND (exp, 2),
@ -6550,16 +6575,17 @@ expand_expr (exp, target, tmode, modifier)
else
temp = assign_temp (type, 0, 0, 1);
/* If we had X ? A + 1 : A and we can do the test of X as a store-flag
operation, do this as A + (X != 0). Similarly for other simple
binary operators. */
/* If we had X ? A + C : A, with C a constant power of 2, and we can
do the test of X as a store-flag operation, do this as
A + ((X != 0) << log C). Similarly for other simple binary
operators. Only do for C == 1 if BRANCH_COST is low. */
if (temp && singleton && binary_op
&& ! TREE_SIDE_EFFECTS (TREE_OPERAND (exp, 0))
&& (TREE_CODE (binary_op) == PLUS_EXPR
|| TREE_CODE (binary_op) == MINUS_EXPR
|| TREE_CODE (binary_op) == BIT_IOR_EXPR
|| TREE_CODE (binary_op) == BIT_XOR_EXPR)
&& integer_onep (TREE_OPERAND (binary_op, 1))
&& (BRANCH_COST >= 3 ? integer_pow2p (TREE_OPERAND (binary_op, 1))
: integer_onep (TREE_OPERAND (binary_op, 1)))
&& TREE_CODE_CLASS (TREE_CODE (TREE_OPERAND (exp, 0))) == '<')
{
rtx result;
@ -6584,6 +6610,15 @@ expand_expr (exp, target, tmode, modifier)
? temp : NULL_RTX),
mode, BRANCH_COST <= 1);
if (result != 0 && ! integer_onep (TREE_OPERAND (binary_op, 1)))
result = expand_shift (LSHIFT_EXPR, mode, result,
build_int_2 (tree_log2
(TREE_OPERAND
(binary_op, 1)),
0),
(safe_from_p (temp, singleton)
? temp : NULL_RTX), 0);
if (result)
{
op1 = expand_expr (singleton, NULL_RTX, VOIDmode, 0);