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author | Sam Feifer <sfeifer@redhat.com> | 2022-07-21 16:31:41 -0400 |
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committer | Sam Feifer <sfeifer@redhat.com> | 2022-07-21 17:24:06 -0400 |
commit | 633e9920589ddfaf2d6da1c24ce99b18a2638db4 (patch) | |
tree | cc5b54b570daae95424bad5f4c2164020cb5052e | |
parent | 28be481cf47d52af8b11972d2394226bbaf87867 (diff) | |
download | gcc-633e9920589ddfaf2d6da1c24ce99b18a2638db4.zip gcc-633e9920589ddfaf2d6da1c24ce99b18a2638db4.tar.gz gcc-633e9920589ddfaf2d6da1c24ce99b18a2638db4.tar.bz2 |
match.pd: Add new abs pattern [PR94920]
This patch is intended to fix a missed optimization in match.pd. It optimizes (x >= 0 ? x : 0) + (x <= 0 ? -x : 0) to just abs(x). Additionally, the pattern (x <= 0 ? -x : 0) now gets optimized to max(-x, 0), which helps with the other simplification rule.
Tests are also included to be added to the testsuite.
Bootstrapped/regtested on x86_64-pc-linux-gnu, ok for trunk?
PR tree-optimization/94920
gcc/ChangeLog:
* match.pd (x >= 0 ? x : 0) + (x <= 0 ? -x : 0): New simplification.
(x <= 0 ? -x : 0): New simplification.
gcc/testsuite/ChangeLog:
* g++.dg/pr94920-1.C: New test.
* g++.dg/pr94920.C: New test.
* gcc.dg/pr94920-2.c: New test.
-rw-r--r-- | gcc/match.pd | 10 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/pr94920-1.C | 17 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/pr94920.C | 63 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/pr94920-2.c | 15 |
4 files changed, 105 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index 88a1a5a..9736393 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -339,6 +339,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@0))) (COPYSIGN_ALL (negate @0) @1))) +/* (x >= 0 ? x : 0) + (x <= 0 ? -x : 0) -> abs x. */ +(simplify + (plus:c (max @0 integer_zerop) (max (negate @0) integer_zerop)) + (abs @0)) + /* X * 1, X / 1 -> X. */ (for op (mult trunc_div ceil_div floor_div round_div exact_div) (simplify @@ -3425,6 +3430,11 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) && (GIMPLE || !TREE_SIDE_EFFECTS (@1))) (cond (convert:boolean_type_node @2) @1 @0))) +/* (x <= 0 ? -x : 0) -> max(-x, 0). */ +(simplify + (cond (le @0 integer_zerop@1) (negate@2 @0) integer_zerop@1) + (max @2 @1)) + /* Simplifications of shift and rotates. */ (for rotate (lrotate rrotate) diff --git a/gcc/testsuite/g++.dg/pr94920-1.C b/gcc/testsuite/g++.dg/pr94920-1.C new file mode 100644 index 0000000..6c6483e --- /dev/null +++ b/gcc/testsuite/g++.dg/pr94920-1.C @@ -0,0 +1,17 @@ +/* PR tree-optimization/94920 */ +/* { dg-do run } */ + +#include "pr94920.C" + +int main() { + + if (foo(0) != 0 + || foo(-42) != 42 + || foo(42) != 42 + || baz(-10) != 10 + || baz(-10) != 10) { + __builtin_abort(); + } + + return 0; +} diff --git a/gcc/testsuite/g++.dg/pr94920.C b/gcc/testsuite/g++.dg/pr94920.C new file mode 100644 index 0000000..925ec4f --- /dev/null +++ b/gcc/testsuite/g++.dg/pr94920.C @@ -0,0 +1,63 @@ +/* PR tree-optimization/94920 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +typedef int __attribute__((vector_size(4*sizeof(int)))) vint; + +/* Same form as PR. */ +__attribute__((noipa)) unsigned int foo(int x) { + return (x >= 0 ? x : 0) + (x <= 0 ? -x : 0); +} + +/* Test for forward propogation. */ +__attribute__((noipa)) unsigned int corge(int x) { + int w = (x >= 0 ? x : 0); + int y = -x; + int z = (y >= 0 ? y : 0); + return w + z; +} + +/* Vector case. */ +__attribute__((noipa)) vint thud(vint x) { + vint t = (x >= 0 ? x : 0) ; + vint xx = -x; + vint t1 = (xx >= 0 ? xx : 0); + return t + t1; +} + +/* Signed function. */ +__attribute__((noipa)) int bar(int x) { + return (x >= 0 ? x : 0) + (x <= 0 ? -x : 0); +} + +/* Commutative property. */ +__attribute__((noipa)) unsigned int baz(int x) { + return (x <= 0 ? -x : 0) + (x >= 0 ? x : 0); +} + +/* Flipped order for max expressions. */ +__attribute__((noipa)) unsigned int quux(int x) { + return (0 <= x ? x : 0) + (0 >= x ? -x : 0); +} + +/* Not zero so should not optimize. */ +__attribute__((noipa)) unsigned int waldo(int x) { + return (x >= 4 ? x : 4) + (x <= 4 ? -x : 4); +} + +/* Not zero so should not optimize. */ +__attribute__((noipa)) unsigned int fred(int x) { + return (x >= -4 ? x : -4) + (x <= -4 ? -x : -4); +} + +/* Incorrect pattern. */ +__attribute__((noipa)) unsigned int goo(int x) { + return (x <= 0 ? x : 0) + (x >= 0 ? -x : 0); +} + +/* Incorrect pattern. */ +__attribute__((noipa)) int qux(int x) { + return (x >= 0 ? x : 0) + (x >= 0 ? x : 0); +} + +/* { dg-final {scan-tree-dump-times " ABS_EXPR " 6 "optimized" } } */ diff --git a/gcc/testsuite/gcc.dg/pr94920-2.c b/gcc/testsuite/gcc.dg/pr94920-2.c new file mode 100644 index 0000000..a2d2332 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr94920-2.c @@ -0,0 +1,15 @@ +/* PR tree-optimization/94920 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -fdump-tree-optimized" } */ + +/* Form from PR. */ +__attribute__((noipa)) unsigned int foo(int x) { + return x <= 0 ? -x : 0; +} + +/* Changed order. */ +__attribute__((noipa)) unsigned int bar(int x) { + return 0 >= x ? -x : 0; +} + +/* { dg-final {scan-tree-dump-times " MAX_EXPR " 2 "optimized" } } */ |