Compares with SMIN + 1 or SMAX - 1 are equivalent to an equality
testing. For example, (x < SMIN + 1) is the same as (x == SMIN).
Canonicalize these to the equality testing since these are usually
simpler to handle.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 8 ++++++++
validation/optim/canonical-cmpe-minmax.c | 1 -
2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/simplify.c b/simplify.c
index f7c6c68d4ce9..ad3adb11595e 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1175,24 +1175,32 @@ static int simplify_compare_constant(struct instruction *insn, long long value)
return replace_with_pseudo(insn, value_pseudo(0));
if (value == sign_mask(size)) // (x < SMAX) --> (x != SMAX)
return replace_opcode(insn, OP_SET_NE);
+ if (value == sign_bit(size) + 1)// (x < SMIN + 1) --> (x == SMIN)
+ return replace_binop_value(insn, OP_SET_EQ, sign_bit(size));
break;
case OP_SET_LE:
if (value == sign_mask(size)) // (x <= SMAX) --> 1
return replace_with_pseudo(insn, value_pseudo(1));
if (value == sign_bit(size)) // (x <= SMIN) --> (x == SMIN)
return replace_opcode(insn, OP_SET_EQ);
+ if (value == sign_mask(size) - 1) // (x <= SMAX - 1) --> (x != SMAX)
+ return replace_binop_value(insn, OP_SET_NE, sign_mask(size));
break;
case OP_SET_GE:
if (value == sign_bit(size)) // (x >= SMIN) --> 1
return replace_with_pseudo(insn, value_pseudo(1));
if (value == sign_mask(size)) // (x >= SMAX) --> (x == SMAX)
return replace_opcode(insn, OP_SET_EQ);
+ if (value == sign_bit(size) + 1)// (x >= SMIN + 1) --> (x != SMIN)
+ return replace_binop_value(insn, OP_SET_NE, sign_bit(size));
break;
case OP_SET_GT:
if (value == sign_mask(size)) // (x > SMAX) --> 0
return replace_with_pseudo(insn, value_pseudo(0));
if (value == sign_bit(size)) // (x > SMIN) --> (x != SMIN)
return replace_opcode(insn, OP_SET_NE);
+ if (value == sign_mask(size) - 1) // (x > SMAX - 1) --> (x == SMAX)
+ return replace_binop_value(insn, OP_SET_EQ, sign_mask(size));
break;
case OP_SET_B:
diff --git a/validation/optim/canonical-cmpe-minmax.c b/validation/optim/canonical-cmpe-minmax.c
index c72819244b95..32b272435fa2 100644
--- a/validation/optim/canonical-cmpe-minmax.c
+++ b/validation/optim/canonical-cmpe-minmax.c
@@ -10,7 +10,6 @@ int ge_smin(int a) { return (a >= (SMIN + 1)) == (a != SMIN); }
/*
* check-name: canonical-cmpe-minmax
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-returns: 1
--
2.30.0
