Simplify away signed compares with SMIN or SMAX which can be
statically be determined to be always true or always false.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
simplify.c | 17 +++++++++++++++++
validation/optim/cmps-minmax.c | 1 -
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/simplify.c b/simplify.c
index a306828c1c4b..096742d51a16 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1170,6 +1170,23 @@ static int simplify_compare_constant(struct instruction *insn, long long value)
int changed = 0;
switch (insn->opcode) {
+ case OP_SET_LT:
+ if (value == sign_bit(size)) // (x < SMIN) --> 0
+ return replace_with_pseudo(insn, value_pseudo(0));
+ break;
+ case OP_SET_LE:
+ if (value == sign_mask(size)) // (x <= SMAX) --> 1
+ return replace_with_pseudo(insn, value_pseudo(1));
+ break;
+ case OP_SET_GE:
+ if (value == sign_bit(size)) // (x >= SMIN) --> 1
+ return replace_with_pseudo(insn, value_pseudo(1));
+ break;
+ case OP_SET_GT:
+ if (value == sign_mask(size)) // (x > SMAX) --> 0
+ return replace_with_pseudo(insn, value_pseudo(0));
+ break;
+
case OP_SET_B:
if (!value) // (x < 0) --> 0
return replace_with_pseudo(insn, value_pseudo(0));
diff --git a/validation/optim/cmps-minmax.c b/validation/optim/cmps-minmax.c
index ded3286cf752..5802cdbcafd1 100644
--- a/validation/optim/cmps-minmax.c
+++ b/validation/optim/cmps-minmax.c
@@ -10,7 +10,6 @@ int gt_smax(int a) { return (a > SMAX) == 0; }
/*
* check-name: cmps-minmax
* check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
*
* check-output-ignore
* check-output-returns: 1
--
2.30.0
