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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-07-31 00:24:17 +0200 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2018-08-06 08:50:52 +0200 |
| commit | 34c4c964d0969a5c594b6bedaa3d749cf1ba6e24 (patch) | |
| tree | 00e978f31a08cecdf418eb85339f1ea2c83c77da | |
| parent | 5fccf5f5a85d01ca21d06675216345a182555cce (diff) | |
| download | sparse-dev-34c4c964d0969a5c594b6bedaa3d749cf1ba6e24.tar.gz | |
simplify SETNE(AND(X,1),0) to AND(X,1)
Since the OP_SETCC instructions can only return a 0 or a 1,
a compare-not-equal-zero or compare-equal-1 is a no-op
if the operand have been masked with 1.
Remove the no-op comparison (if the size matches).
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | simplify.c | 10 | ||||
| -rw-r--r-- | validation/optim/mask1-setne0.c | 1 |
2 files changed, 10 insertions, 1 deletions
@@ -713,6 +713,16 @@ static int simplify_seteq_setne(struct instruction *insn, long long value) } opcode = def->opcode; switch (opcode) { + case OP_AND: + if (inverse) + break; + if (def->size != insn->size) + break; + if (def->src2->type != PSEUDO_VAL) + break; + if (def->src2->value != 1) + break; + return replace_with_pseudo(insn, old); case OP_FPCMP ... OP_BINCMP_END: // Convert: // setcc.n %t <- %a, %b diff --git a/validation/optim/mask1-setne0.c b/validation/optim/mask1-setne0.c index 8810189c..1e599dc8 100644 --- a/validation/optim/mask1-setne0.c +++ b/validation/optim/mask1-setne0.c @@ -16,7 +16,6 @@ int foo(struct s x) /* * check-name: mask1-setne0 * check-command: test-linearize -Wno-decl $file - * check-known-to-fail * * check-output-start foo: |