[Bug tree-optimization/103514] Missing XOR-EQ-AND Optimization
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 --- Comment #5 from CVS Commits --- The master branch has been updated by Jakub Jelinek : https://gcc.gnu.org/g:263a5944fc806396ecc3eff3d96277602e88ae2b commit r12-6942-g263a5944fc806396ecc3eff3d96277602e88ae2b Author: Jakub Jelinek Date: Mon Jan 31 10:30:58 2022 +0100 testsuite: Fix up tree-ssa/pr103514.c testcase [PR103514] > > PR tree-optimization/103514 > > * match.pd (a & b) ^ (a == b) -> !(a | b): New optimization. > > * match.pd (a & b) == (a ^ b) -> !(a | b): New optimization. > > * gcc.dg/tree-ssa/pr103514.c: Testcase for this optimization. > > > > 1) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 > Note the bug was filed an fixed during stage3, review just didn't happen in > a reasonable timeframe. > > I'm going to ACK this for the trunk and go ahead and commit it for you. The testcase FAILs on short-circuit targets like powerpc64le-linux. While the first 2 functions are identical, the last two look like: : if (a_5(D) != 0) goto ; [INV] else goto ; [INV] : if (b_6(D) != 0) goto ; [INV] else goto ; [INV] : : # iftmp.1_4 = PHI <1(3), 0(4)> _1 = a_5(D) == b_6(D); _2 = (int) _1; _3 = _2 ^ iftmp.1_4; _9 = _2 != iftmp.1_4; return _9; instead of the expected: : _3 = a_8(D) & b_9(D); _4 = (int) _3; _5 = a_8(D) == b_9(D); _6 = (int) _5; _1 = a_8(D) | b_9(D); _2 = ~_1; _7 = (int) _2; _10 = ~_1; return _10; so no wonder it doesn't match. E.g. x86_64-linux will also use jumps if it isn't just a && b but a && b && c && d (will do a & b and c & d tests and jump based on those. As it is too late to implement this optimization even for the short circuiting targets this late (not even sure which pass would be best), this patch just forces non-short-circuiting for the test. 2022-01-31 Jakub Jelinek PR tree-optimization/103514 * gcc.dg/tree-ssa/pr103514.c: Add --param logical-op-non-short-circuit=1 to dg-options.
[Bug tree-optimization/103514] Missing XOR-EQ-AND Optimization
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 Navid Rahimi changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #4 from Navid Rahimi --- Thanks Jeff.
[Bug tree-optimization/103514] Missing XOR-EQ-AND Optimization
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 --- Comment #3 from CVS Commits --- The master branch has been updated by Jeff Law : https://gcc.gnu.org/g:cb3ac1985a5332fa811a62844adb33ca140bd4ba commit r12-6928-gcb3ac1985a5332fa811a62844adb33ca140bd4ba Author: Navid Rahimi Date: Fri Jan 28 17:11:30 2022 -0500 tree-optimization/103514 Missing XOR-EQ-AND Optimization This patch will add the missed pattern described in bug 103514 [1] to the match.pd. [1] includes proof of correctness for the patch too. 1) https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 gcc/ PR tree-optimization/103514 * match.pd (a & b) ^ (a == b) -> !(a | b): New optimization. (a & b) == (a ^ b) -> !(a | b): New optimization. gcc/testsuite * gcc.dg/tree-ssa/pr103514.c: Testcase for this optimization.
[Bug tree-optimization/103514] Missing XOR-EQ-AND Optimization
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 Richard Biener changed: What|Removed |Added Version|unknown |12.0 Ever confirmed|0 |1 Keywords||missed-optimization Last reconfirmed||2021-12-01 Status|UNCONFIRMED |NEW
[Bug tree-optimization/103514] Missing XOR-EQ-AND Optimization
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 --- Comment #2 from Navid Rahimi --- Exactly. Actually in my final version I had it with single loop, but didn't know I can remove the condition too. Thanks Andrew.
[Bug tree-optimization/103514] Missing XOR-EQ-AND Optimization
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103514 --- Comment #1 from Andrew Pinski --- Note the loop should be: (for first_op (bit_xor eq ) second_op (eq bit_xor) (simplify (first_op:c (bit_and:c truth_valued_p@0 truth_valued_p@1) (second_op:c @0 @1)) (bit_not (bit_ior @0 @1) No reason fore the double for loop
