From: Andrew Pinski
This copies the optimization that is done in phiopt for
"x < 0 ? ~y : y to (x >> 31) ^ y" into match.pd. The code
for phiopt is kept around until phiopt uses match.pd (which
I am working towards).
Note the original testcase is now optimized early on and I added a
new testcase to optimize during phiopt.
OK? Bootstrapped and tested on x86_64-linux-gnu with no regressions.
Thanks,
Andrew Pinski
gcc:
* match.pd (x < 0 ? ~y : y): New patterns.
gcc/testsuite:
* gcc.dg/tree-ssa/pr96928.c: Update test for slightly different IR.
* gcc.dg/tree-ssa/pr96928-1.c: New testcase.
---
gcc/match.pd | 30 +++
gcc/testsuite/gcc.dg/tree-ssa/pr96928-1.c | 48 +++
gcc/testsuite/gcc.dg/tree-ssa/pr96928.c | 7 +++--
3 files changed, 83 insertions(+), 2 deletions(-)
create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr96928-1.c
diff --git a/gcc/match.pd b/gcc/match.pd
index ad6b057..6710aa9 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -4875,6 +4875,36 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
(cmp (bit_and@2 @0 integer_pow2p@1) @1)
(icmp @2 { build_zero_cst (TREE_TYPE (@0)); })))
+(for cmp (ge lt)
+/* x < 0 ? ~y : y into (x >> (prec-1)) ^ y. */
+/* x >= 0 ? ~y : y into ~((x >> (prec-1)) ^ y). */
+ (simplify
+ (cond (cmp @0 integer_zerop) (bit_not @1) @1)
+ (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+&& !TYPE_UNSIGNED (TREE_TYPE (@0))
+&& TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (type))
+(with
+ {
+ tree shifter = build_int_cst (integer_type_node, TYPE_PRECISION (type)
- 1);
+ }
+(if (cmp == LT_EXPR)
+ (bit_xor (convert (rshift @0 {shifter;})) @1)
+ (bit_not (bit_xor (convert (rshift @0 {shifter;})) @1))
+/* x < 0 ? y : ~y into ~((x >> (prec-1)) ^ y). */
+/* x >= 0 ? y : ~y into (x >> (prec-1)) ^ y. */
+ (simplify
+ (cond (cmp @0 integer_zerop) @1 (bit_not @1))
+ (if (INTEGRAL_TYPE_P (TREE_TYPE (@0))
+&& !TYPE_UNSIGNED (TREE_TYPE (@0))
+&& TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (type))
+(with
+ {
+ tree shifter = build_int_cst (integer_type_node, TYPE_PRECISION (type)
- 1);
+ }
+(if (cmp == GE_EXPR)
+ (bit_xor (convert (rshift @0 {shifter;})) @1)
+ (bit_not (bit_xor (convert (rshift @0 {shifter;})) @1)))
+
/* If we have (A & C) != 0 ? D : 0 where C and D are powers of 2,
convert this into a shift followed by ANDing with D. */
(simplify
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr96928-1.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr96928-1.c
new file mode 100644
index 000..a2770e5
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr96928-1.c
@@ -0,0 +1,48 @@
+/* PR tree-optimization/96928 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-phiopt2" } */
+/* { dg-final { scan-tree-dump-times " = a_\[0-9]*\\\(D\\\) >> " 5 "phiopt2" }
} */
+/* { dg-final { scan-tree-dump-times " = ~c_\[0-9]*\\\(D\\\);" 1 "phiopt2" } }
*/
+/* { dg-final { scan-tree-dump-times " = ~" 1 "phiopt2" } } */
+/* { dg-final { scan-tree-dump-times " = \[abc_0-9\\\(\\\)D]* \\\^ " 5
"phiopt2" } } */
+/* { dg-final { scan-tree-dump-not "a < 0" "phiopt2" } } */
+
+int
+foo (int a)
+{
+ if (a < 0)
+return ~a;
+ return a;
+}
+
+int
+bar (int a, int b)
+{
+ if (a < 0)
+return ~b;
+ return b;
+}
+
+unsigned
+baz (int a, unsigned int b)
+{
+ if (a < 0)
+return ~b;
+ return b;
+}
+
+unsigned
+qux (int a, unsigned int c)
+{
+ if (a >= 0)
+return ~c;
+ return c;
+}
+
+int
+corge (int a, int b)
+{
+ if (a >= 0)
+return b;
+ return ~b;
+}
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr96928.c
b/gcc/testsuite/gcc.dg/tree-ssa/pr96928.c
index 2091357..e8fd82f 100644
--- a/gcc/testsuite/gcc.dg/tree-ssa/pr96928.c
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr96928.c
@@ -1,8 +1,11 @@
/* PR tree-optimization/96928 */
/* { dg-do compile } */
-/* { dg-options "-O2 -fdump-tree-phiopt2" } */
+/* { dg-options "-O2 -fdump-tree-phiopt2 -fdump-tree-optimized" } */
/* { dg-final { scan-tree-dump-times " = a_\[0-9]*\\\(D\\\) >> " 5 "phiopt2" }
} */
-/* { dg-final { scan-tree-dump-times " = ~c_\[0-9]*\\\(D\\\);" 1 "phiopt2" } }
*/
+/* The following check is done at optimized because a ^ (~b) is rewritten as
~(a^b)
+ and in the case of match.pd optimizing these ?:, the ~ is moved out already
+ by the time we get to phiopt2. */
+/* { dg-final { scan-tree-dump-times "\\\^ c_\[0-9]*\\\(D\\\);" 1 "optimized"
} } */
/* { dg-final { scan-tree-dump-times " = ~" 1 "phiopt2" } } */
/* { dg-final { scan-tree-dump-times " = \[abc_0-9\\\(\\\)D]* \\\^ " 5
"phiopt2" } } */
/* { dg-final { scan-tree-dump-not "a < 0" "phiopt2" } } */
--
1.8.3.1
