@@ -4663,6 +4663,19 @@ simplify_relational_operation_1 (enum rtx_code code, machine_mode mode,
cmp_mode, XEXP (op0, 0), new_cmp);
}
+ /* (GTU (PLUS a C) (C - 1)) where C is a non-zero constant can be
+ transformed into (LTU a -C). */
+ if (code == GTU && GET_CODE (op0) == PLUS && CONST_INT_P (op1)
+ && CONST_INT_P (XEXP (op0, 1))
+ && (UINTVAL (op1) == UINTVAL (XEXP (op0, 1)) - 1)
+ && XEXP (op0, 1) != const0_rtx)
+ {
+ rtx new_cmp
+ = simplify_gen_unary (NEG, cmp_mode, XEXP (op0, 1), cmp_mode);
+ return simplify_gen_relational (LTU, mode, cmp_mode,
+ XEXP (op0, 0), new_cmp);
+ }
+
/* Canonicalize (LTU/GEU (PLUS a b) b) as (LTU/GEU (PLUS a b) a). */
if ((code == LTU || code == GEU)
&& GET_CODE (op0) == PLUS
new file mode 100644
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int
+f1 (int x, int t)
+{
+ if (x == -1 || x == -2)
+ t = 1;
+
+ return t;
+}
+
+/* { dg-final { scan-assembler-times "cmn\\tw\[0-9\]+, #2" 1 } } */
new file mode 100644
@@ -0,0 +1,11 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+unsigned int
+foo (unsigned int a, unsigned int b)
+{
+ return (a + 10) > 9;
+}
+
+/* { dg-final { scan-assembler-times "cmn\\tw\[0-9\]+" 1 } } */
+/* { dg-final { scan-assembler-not "add\\tw\[0-9\]+" } } */