[SystemZ] Try reversing comparisons whose first operand is in memory
This allows us to make more use of the many compare reg,mem instructions.
llvm-svn: 189099
diff --git a/llvm/test/CodeGen/SystemZ/int-cmp-42.ll b/llvm/test/CodeGen/SystemZ/int-cmp-42.ll
index 26a268d..94ef008 100644
--- a/llvm/test/CodeGen/SystemZ/int-cmp-42.ll
+++ b/llvm/test/CodeGen/SystemZ/int-cmp-42.ll
@@ -100,3 +100,22 @@
%res = phi i64 [ %src1, %entry ], [ %mul, %mulb ]
ret i64 %res
}
+
+; Check the comparison can be reversed if that allows CLGFRL to be used.
+define i64 @f6(i64 %src2) {
+; CHECK-LABEL: f6:
+; CHECK: clgfrl %r2, g
+; CHECK-NEXT: jh {{\.L.*}}
+; CHECK: br %r14
+entry:
+ %val = load i32 *@g
+ %src1 = zext i32 %val to i64
+ %cond = icmp ult i64 %src1, %src2
+ br i1 %cond, label %exit, label %mulb
+mulb:
+ %mul = mul i64 %src2, %src2
+ br label %exit
+exit:
+ %res = phi i64 [ %src2, %entry ], [ %mul, %mulb ]
+ ret i64 %res
+}