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| author | Andrew Pinski <pinskia@gmail.com> | 2023-10-24 23:13:18 +0000 |
|---|---|---|
| committer | Andrew Pinski <pinskia@gmail.com> | 2023-10-26 18:58:40 +0000 |
| commit | 662655e22dddf5392d9aa67fce45beee980e5454 (patch) | |
| tree | 4e7c52a3141a8644d9ee3bd0525a83e7bbdc5894 | |
| parent | abd78dc61076120649ccc1ca0b1d74d0b0a22f81 (diff) | |
| download | gcc-662655e22dddf5392d9aa67fce45beee980e5454.zip gcc-662655e22dddf5392d9aa67fce45beee980e5454.tar.gz gcc-662655e22dddf5392d9aa67fce45beee980e5454.tar.bz2 | |
match: Simplify `a != C1 ? abs(a) : C2` when C2 == abs(C1) [PR111957]
This adds a match pattern for `a != C1 ? abs(a) : C2` which gets simplified
to `abs(a)`. if C1 was originally *_MIN then change it over to use absu instead
of abs.
Bootstrapped and tested on x86_64-linux-gnu with no regressions.
PR tree-optimization/111957
gcc/ChangeLog:
* match.pd (`a != C1 ? abs(a) : C2`): New pattern.
gcc/testsuite/ChangeLog:
* gcc.dg/tree-ssa/phi-opt-40.c: New test.
| -rw-r--r-- | gcc/match.pd | 10 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/phi-opt-40.c | 25 |
2 files changed, 35 insertions, 0 deletions
diff --git a/gcc/match.pd b/gcc/match.pd index f725a68..5f6aeb0 100644 --- a/gcc/match.pd +++ b/gcc/match.pd @@ -5611,6 +5611,16 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) (if (wi::eq_p (wi::bit_not (wi::to_wide (@1)), wi::to_wide (@2))) @3)) +/* X != C1 ? abs(X) : C2 simplifies to abs(x) when abs(C1) == C2. */ +(for op (abs absu) + (simplify + (cond (ne @0 INTEGER_CST@1) (op@3 @0) INTEGER_CST@2) + (if (wi::abs (wi::to_wide (@1)) == wi::to_wide (@2)) + (if (op != ABSU_EXPR && wi::only_sign_bit_p (wi::to_wide (@1))) + (with { tree utype = unsigned_type_for (TREE_TYPE (@0)); } + (convert (absu:utype @0))) + @3)))) + /* (X + 1) > Y ? -X : 1 simplifies to X >= Y ? -X : 1 when X is unsigned, as when X + 1 overflows, X is -1, so -X == 1. */ (simplify diff --git a/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-40.c b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-40.c new file mode 100644 index 0000000..a9011ce --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/phi-opt-40.c @@ -0,0 +1,25 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fdump-tree-phiopt" } */ +/* PR tree-optimization/111957 */ + +int f(int a) +{ + if (a) + return a > 0 ? a : -a; + return 0; +} + +int f1(int x) +{ + int intmin = (-1u >> 1); + intmin = -intmin - 1; + if (x != intmin) + return x > 0 ? x : -x; + return intmin; +} + +/* { dg-final { scan-tree-dump-times "if " 1 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-not "if " "phiopt2" } } */ +/* { dg-final { scan-tree-dump-times "ABS_EXPR <" 2 "phiopt1" } } */ +/* { dg-final { scan-tree-dump-times "ABS_EXPR <" 1 "phiopt2" } } */ +/* { dg-final { scan-tree-dump-times "ABSU_EXPR <" 1 "phiopt2" } } */ |