Teach the ARM peephole optimizer that RSB, RSC, ADC, and SBC can be used for folded comparisons, just like ADD and SUB.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129038 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/ARM/sub.ll b/test/CodeGen/ARM/sub.ll
index 7ada14d..555b18e 100644
--- a/test/CodeGen/ARM/sub.ll
+++ b/test/CodeGen/ARM/sub.ll
@@ -27,3 +27,12 @@
ret i64 %tmp
}
+define i32 @f4(i32 %x) {
+entry:
+; CHECK: f4
+; CHECK: rsbs
+ %sub = sub i32 1, %x
+ %cmp = icmp ugt i32 %sub, 0
+ %sel = select i1 %cmp, i32 1, i32 %sub
+ ret i32 %sel
+}