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

Simplify more EXACT_DIV_EXPR comparisons

Browse source 
2019-05-31  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* match.pd (X/[ex]D<Y/[ex]D): Handle negative denominator.
	((size_t)(A /[ex] B) CMP C): New transformation.

gcc/testsuite/
	* gcc.dg/tree-ssa/cmpexactdiv-3.c: New file.
	* gcc.dg/tree-ssa/cmpexactdiv-4.c: New file.
	* gcc.dg/Walloca-13.c: Xfail.

From-SVN: r271816
This commit is contained in:
Marc Glisse 2019-05-31 18:54:30 +02:00 • committed by Marc Glisse
parent f4fde1b378
commit 9cf60d3b0d
6 changed files with 62 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

5
gcc/ChangeLog
View file

@ -1,3 +1,8 @@
2019-05-31 Marc Glisse <marc.glisse@inria.fr>
* match.pd (X/[ex]D<Y/[ex]D): Handle negative denominator.
((size_t)(A /[ex] B) CMP C): New transformation.
2019-05-31 Richard Sandiford <richard.sandiford@arm.com>
* doc/md.texi: Document define_insn_and_rewrite.

31
gcc/match.pd
View file

@ -1497,7 +1497,9 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(simplify
(cmp (exact_div @0 INTEGER_CST@2) (exact_div @1 @2))
(if (wi::gt_p (wi::to_wide (@2), 0, TYPE_SIGN (TREE_TYPE (@2))))
(cmp @0 @1))))
(cmp @0 @1)
(if (wi::lt_p (wi::to_wide (@2), 0, TYPE_SIGN (TREE_TYPE (@2))))
(cmp @1 @0)))))
/* X / C1 op C2 into a simple range test. */
(for cmp (simple_comparison)
@ -3633,6 +3635,33 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
!= (cmp == LT_EXPR || cmp == LE_EXPR), type); }
(cmp @0 { wide_int_to_tree (TREE_TYPE (@0), prod); }))))))
/* Fold (size_t)(A /[ex] B) CMP C to (size_t)A CMP (size_t)B * C or A CMP' 0.
For small C (less than max/B), this is (size_t)A CMP (size_t)B * C.
For large C (more than min/B+2^size), this is also true, with the
multiplication computed modulo 2^size.
For intermediate C, this just tests the sign of A. */
(for cmp (lt le gt ge)
cmp2 (ge ge lt lt)
(simplify
(cmp (convert (exact_div @0 INTEGER_CST@1)) INTEGER_CST@2)
(if (tree_nop_conversion_p (TREE_TYPE (@0), TREE_TYPE (@2))
&& TYPE_UNSIGNED (TREE_TYPE (@2)) && !TYPE_UNSIGNED (TREE_TYPE (@0))
&& wi::gt_p (wi::to_wide (@1), 0, TYPE_SIGN (TREE_TYPE (@1))))
(with
{
tree utype = TREE_TYPE (@2);
wide_int denom = wi::to_wide (@1);
wide_int right = wi::to_wide (@2);
wide_int smax = wi::sdiv_trunc (wi::max_value (TREE_TYPE (@0)), denom);
wide_int smin = wi::sdiv_trunc (wi::min_value (TREE_TYPE (@0)), denom);
bool small = wi::leu_p (right, smax);
bool large = wi::geu_p (right, smin);
}
(if (small || large)
(cmp (convert:utype @0) (mult @2 (convert @1)))
(cmp2 @0 { build_zero_cst (TREE_TYPE (@0)); }))))))
/* Unordered tests if either argument is a NaN. */
(simplify
(bit_ior (unordered @0 @0) (unordered @1 @1))

6
gcc/testsuite/ChangeLog
View file

@ -1,3 +1,9 @@
2019-05-31 Marc Glisse <marc.glisse@inria.fr>
* gcc.dg/tree-ssa/cmpexactdiv-3.c: New file.
* gcc.dg/tree-ssa/cmpexactdiv-4.c: New file.
* gcc.dg/Walloca-13.c: Xfail.
2019-05-31 Bill Schmidt <wschmidt@linux.ibm.com>
Michael Meissner <meissner@linux.ibm.com>

2
gcc/testsuite/gcc.dg/Walloca-13.c
View file

@ -8,5 +8,5 @@ void g (int *p, int *q)
{
__SIZE_TYPE__ n = (__SIZE_TYPE__)(p - q);
if (n < 100)
f (__builtin_alloca (n));
f (__builtin_alloca (n)); // { dg-bogus "may be too large due to conversion" "" { xfail { *-*-* } } }
}

10
gcc/testsuite/gcc.dg/tree-ssa/cmpexactdiv-3.c Normal file
View file

@ -0,0 +1,10 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-optimized-raw" } */
int f(int*a,int*b){
if(sizeof(__SIZE_TYPE__)!=sizeof(__PTRDIFF_TYPE__)) return -1;
__SIZE_TYPE__ d = b - a;
return d >= 5;
}
/* { dg-final { scan-tree-dump-not "exact_div_expr" "optimized" } } */

10
gcc/testsuite/gcc.dg/tree-ssa/cmpexactdiv-4.c Normal file
View file

@ -0,0 +1,10 @@
/* { dg-do compile } */
/* { dg-options "-O -fdump-tree-optimized-raw" } */
int f(int*a,int*b,int*c){
__PTRDIFF_TYPE__ x = -(b - a);
__PTRDIFF_TYPE__ y = -(c - a);
return x < y;
}
/* { dg-final { scan-tree-dump-not "exact_div_expr" "optimized" } } */