procyberian/gcc
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

tree-ssa-phiopt.c (conditional_replacement): Replace PHIs whose arguments are -1 and 0...

Browse source 
2012-04-27  Paolo Bonzini  <bonzini@gnu.org>

	* tree-ssa-phiopt.c (conditional_replacement): Replace PHIs
	whose arguments are -1 and 0, by negating the result of the
	conditional.

testsuite:
2012-04-27  Paolo Bonzini  <bonzini@gnu.org>

	* gcc.c-torture/execute/20120427-2.c: New testcase.
	* gcc.dg/tree-ssa/phi-opt-10.c: New testcase.
	* gcc.dg/tree-ssa/ssa-pre-28.c: Bypass new optimization.
	* gcc.dg/tree-ssa/ssa-ifcombine-7.c: Look into ifcombine dump.

From-SVN: r186905
This commit is contained in:
Paolo Bonzini 2012-04-27 12:20:01 +00:00 • committed by Paolo Bonzini
parent d554870991
commit 809c929ccf
7 changed files with 86 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

6
gcc/ChangeLog
View file

@ -1,3 +1,9 @@
2012-04-27 Paolo Bonzini <bonzini@gnu.org>
* tree-ssa-phiopt.c (conditional_replacement): Replace PHIs
whose arguments are -1 and 0, by negating the result of the
conditional.
2012-04-27 Paolo Bonzini <bonzini@gnu.org>
PR target/53138

7
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,10 @@
2012-04-27 Paolo Bonzini <bonzini@gnu.org>
* gcc.c-torture/execute/20120427-2.c: New testcase.
* gcc.dg/tree-ssa/phi-opt-10.c: New testcase.
* gcc.dg/tree-ssa/ssa-pre-28.c: Bypass new optimization.
* gcc.dg/tree-ssa/ssa-ifcombine-7.c: Look into ifcombine dump.
2012-04-27 Paolo Bonzini <bonzini@gnu.org>
PR target/53138

38
gcc/testsuite/gcc.c-torture/execute/20120427-2.c Normal file
View file

@ -0,0 +1,38 @@
typedef struct sreal
{
unsigned sig; /* Significant. */
int exp; /* Exponent. */
} sreal;
sreal_compare (sreal *a, sreal *b)
{
if (a->exp > b->exp)
return 1;
if (a->exp < b->exp)
return -1;
if (a->sig > b->sig)
return 1;
if (a->sig < b->sig)
return -1;
return 0;
}
sreal a[] = {
{ 0, 0 },
{ 1, 0 },
{ 0, 1 },
{ 1, 1 }
};
int main()
{
int i, j;
for (i = 0; i <= 3; i++) {
for (j = 0; j < 3; j++) {
if (i < j && sreal_compare(&a[i], &a[j]) != -1) abort();
if (i == j && sreal_compare(&a[i], &a[j]) != 0) abort();
if (i > j && sreal_compare(&a[i], &a[j]) != 1) abort();
}
}
return 0;
}

11
gcc/testsuite/gcc.dg/tree-ssa/phi-opt-10.c Normal file
View file

@ -0,0 +1,11 @@
/* { dg-do compile } */
/* { dg-options "-O1 -fdump-tree-optimized" } */
int nem1_phi (unsigned long a) { return a ? -1 : 0; }
int eqm1_phi (unsigned long a) { return a ? 0 : -1; }
int spaceship1 (long a) { return a > 0 ? 1 : a < 0 ? -1 : 0; }
int spaceship2 (long a) { return a > 0 ? 1 : a == 0 ? 0 : -1; }
/* { dg-final { scan-tree-dump-times " = -D" 4 "optimized"} } */
/* { dg-final { cleanup-tree-dump "optimized" } } */

6
gcc/testsuite/gcc.dg/tree-ssa/ssa-ifcombine-7.c
View file

@ -1,5 +1,5 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-optimized" } */
/* { dg-options "-O -fdump-tree-ifcombine" } */
int test1 (int i, int j)
{
@ -11,5 +11,5 @@ int test1 (int i, int j)
/* The above should be optimized to a i > j test by ifcombine. */
/* { dg-final { scan-tree-dump " > " "optimized" } } */
/* { dg-final { cleanup-tree-dump "optimized" } } */
/* { dg-final { scan-tree-dump " > " "ifcombine" } } */
/* { dg-final { cleanup-tree-dump "ifcombine" } } */

4
gcc/testsuite/gcc.dg/tree-ssa/ssa-pre-28.c
View file

@ -6,7 +6,7 @@ int foo (int i, int b, int result)
{
int mask;
if (b)
mask = -1;
mask = -2;
else
mask = 0;
result = i + 1;
@ -15,7 +15,7 @@ int foo (int i, int b, int result)
}
/* We should insert i + 1 into the if (b) path as well as the simplified
i + 1 & -1 expression. And do replacement with two PHI temps. */
i + 1 & -2 expression. And do replacement with two PHI temps. */
/* { dg-final { scan-tree-dump-times "with prephitmp" 2 "pre" } } */
/* { dg-final { cleanup-tree-dump "pre" } } */

26
gcc/tree-ssa-phiopt.c
View file

@ -536,17 +536,21 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb,
gimple_stmt_iterator gsi;
edge true_edge, false_edge;
tree new_var, new_var2;
bool neg;
/* FIXME: Gimplification of complex type is too hard for now. */
if (TREE_CODE (TREE_TYPE (arg0)) == COMPLEX_TYPE
|| TREE_CODE (TREE_TYPE (arg1)) == COMPLEX_TYPE)
return false;
/* The PHI arguments have the constants 0 and 1, then convert
it to the conditional. */
/* The PHI arguments have the constants 0 and 1, or 0 and -1, then
convert it to the conditional. */
if ((integer_zerop (arg0) && integer_onep (arg1))
|| (integer_zerop (arg1) && integer_onep (arg0)))
;
neg = false;
else if ((integer_zerop (arg0) && integer_all_onesp (arg1))
|| (integer_zerop (arg1) && integer_all_onesp (arg0)))
neg = true;
else
return false;
@ -558,7 +562,7 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb,
falls through into BB.
There is a single PHI node at the join point (BB) and its arguments
are constants (0, 1).
are constants (0, 1) or (0, -1).
So, given the condition COND, and the two PHI arguments, we can
rewrite this PHI into non-branching code:
@ -585,11 +589,19 @@ conditional_replacement (basic_block cond_bb, basic_block middle_bb,
edge so that we know when to invert the condition below. */
extract_true_false_edges_from_block (cond_bb, &true_edge, &false_edge);
if ((e0 == true_edge && integer_zerop (arg0))
|| (e0 == false_edge && integer_onep (arg0))
|| (e0 == false_edge && !integer_zerop (arg0))
|| (e1 == true_edge && integer_zerop (arg1))
|| (e1 == false_edge && integer_onep (arg1)))
|| (e1 == false_edge && !integer_zerop (arg1)))
cond = fold_build1_loc (gimple_location (stmt),
TRUTH_NOT_EXPR, TREE_TYPE (cond), cond);
TRUTH_NOT_EXPR, TREE_TYPE (cond), cond);
if (neg)
{
cond = fold_convert_loc (gimple_location (stmt),
TREE_TYPE (result), cond);
cond = fold_build1_loc (gimple_location (stmt),
NEGATE_EXPR, TREE_TYPE (cond), cond);
}
/* Insert our new statements at the end of conditional block before the
COND_STMT. */