2 files changed, 14 insertions, 1 deletions
diff --git a/simplify.c b/simplify.c
index 1cb5275b..a5991869 100644
--- a/simplify.c
+++ b/simplify.c
@@ -1148,6 +1148,20 @@ static int simplify_compare_constant(struct instruction *insn, long long value)
 			insn->src2 = value_pseudo(zero_extend(value, osize));
 			return replace_pseudo(insn, &insn->src1, def->src);
 		}
+		switch (insn->opcode) {
+		case OP_SET_LT: case OP_SET_LE:
+			if (value >= sign_bit(osize))
+				return replace_with_value(insn, 1);
+			else
+				return replace_with_value(insn, 0);
+			break;
+		case OP_SET_GE: case OP_SET_GT:
+			if (value >= sign_bit(osize))
+				return replace_with_value(insn, 0);
+			else
+				return replace_with_value(insn, 1);
+			break;
+		}
 		break;
 	case OP_ZEXT:
 		osize = def->orig_type->bit_size;
diff --git a/validation/optim/cmp-sext-simm.c b/validation/optim/cmp-sext-simm.c
index c2099a6b..a8b2a8f9 100644
--- a/validation/optim/cmp-sext-simm.c
+++ b/validation/optim/cmp-sext-simm.c
@@ -23,7 +23,6 @@ static int ge_lt1(int x) { return (sext(x) >= (NEG - 1)) == 0; }
 /*
  * check-name: cmp-sext-simm
  * check-command: test-linearize -Wno-decl $file
- * check-known-to-fail
  *
  * check-output-ignore
  * check-output-returns: 1