Convert the OP_TRUNC into an OP_AND with the appropriate mask.
This a greater chance to simplify with previous instructions
and to correspond to a register-size operand.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 17 +++++++++++++++++
validation/optim/trunc-setne0.c | 1 -
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/simplify.c b/simplify.c
index ae53e7ae7..911bfde7e 100644
--- a/simplify.c
+++ b/simplify.c
@@ -690,6 +690,7 @@ static int simplify_seteq_setne(struct instruction *insn, long long value)
{
pseudo_t old = insn->src1;
struct instruction *def;
+ unsigned osize;
int inverse;
int opcode;
@@ -749,6 +750,22 @@ static int simplify_seteq_setne(struct instruction *insn, long long value)
// setne.1 %s <- %a, $0
// and same for setne/eq ... 0/1
return replace_pseudo(insn, &insn->src1, def->src);
+ case OP_TRUNC:
+ if (nbr_users(old) > 1)
+ break;
+ // convert
+ // trunc.n %s <- (o) %a
+ // setne.m %r <- %s, $0
+ // into:
+ // and.o %s <- %a, $((1 << o) - 1)
+ // setne.m %r <- %a, $0
+ // and same for setne/eq ... 0/1
+ osize = def->size;
+ def->opcode = OP_AND;
+ def->type = def->orig_type;
+ def->size = def->type->bit_size;
+ def->src2 = value_pseudo(bits_mask(osize));
+ return REPEAT_CSE;
}
return 0;
}
diff --git a/validation/optim/trunc-setne0.c b/validation/optim/trunc-setne0.c
index 16f99a88c..878c05fa6 100644
--- a/validation/optim/trunc-setne0.c
+++ b/validation/optim/trunc-setne0.c
@@ -13,7 +13,6 @@ unsigned int foo(struct s x)
/*
* check-name: trunc-setne0
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-contains: and\\.
--
2.18.0
--
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