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| author | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-11-07 01:09:07 +0100 |
|---|---|---|
| committer | Luc Van Oostenryck <luc.vanoostenryck@gmail.com> | 2020-11-07 12:27:49 +0100 |
| commit | 84bf7462ebc80b350b0d2b35156bae04b8d5feb1 (patch) | |
| tree | 03156e3b9efafed7777e0c4a82d4259206de4223 | |
| parent | 93bb38fdbfb16f8382954db1e02a6ff1731bd60f (diff) | |
| download | sparse-84bf7462ebc80b350b0d2b35156bae04b8d5feb1.tar.gz | |
select: simplify SEL(SEL(x, C1, C2), y, z) --> y (with C1, C2 != 0)
If the condition of a select is also a select, with constant
but non-zero operands, then the result of this inner select
is always true and the outer select can be replaced by its
second operand.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
| -rw-r--r-- | simplify.c | 3 | ||||
| -rw-r--r-- | validation/optim/select-select-true-true.c | 1 |
2 files changed, 3 insertions, 1 deletions
@@ -1793,6 +1793,7 @@ static int simplify_select(struct instruction *insn) // SEL(SEL(x, C, 0), y, z) --> SEL(x, y, z) // SEL(SEL(x, C, 0), C, 0) --> SEL(x, C, 0) == cond // SEL(SEL(x, 0, C), y, z) --> SEL(x, z, y) + // SEL(SEL(x, C1, C2), y, z) --> y if (!def->src3->value) { if ((src1 == def->src2) && (src2 == def->src3)) return replace_with_pseudo(insn, cond); @@ -1802,6 +1803,8 @@ static int simplify_select(struct instruction *insn) switch_pseudo(insn, &insn->src2, insn, &insn->src3); return replace_pseudo(insn, &insn->cond, def->cond); } + // both values must be non-zero + return replace_with_pseudo(insn, src1); } break; } diff --git a/validation/optim/select-select-true-true.c b/validation/optim/select-select-true-true.c index e6fa2c89..c0c26fdd 100644 --- a/validation/optim/select-select-true-true.c +++ b/validation/optim/select-select-true-true.c @@ -3,7 +3,6 @@ int foo(int p, int a, int b) { return ((p ? 42 : 43) ? a : b) == a ; } /* * check-name: select-select-true-true * check-command: test-linearize -Wno-decl $file - * check-known-to-fail * * check-output-ignore * check-output-returns: 1 |