[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-06.ll b/llvm/test/CodeGen/SystemZ/int-cmp-06.ll
index cdd6114..8ab62e8 100644
--- a/llvm/test/CodeGen/SystemZ/int-cmp-06.ll
+++ b/llvm/test/CodeGen/SystemZ/int-cmp-06.ll
@@ -104,7 +104,7 @@
ret double %res
}
-; Check unsigned comparisonn with memory.
+; Check unsigned comparison with memory.
define double @f9(double %a, double %b, i64 %i1, i32 *%ptr) {
; CHECK-LABEL: f9:
; CHECK: clgf %r2, 0(%r3)
@@ -340,3 +340,17 @@
ret i64 %sel9
}
+
+; Check the comparison can be reversed if that allows CLGF to be used.
+define double @f20(double %a, double %b, i64 %i2, i32 *%ptr) {
+; CHECK-LABEL: f20:
+; CHECK: clgf %r2, 0(%r3)
+; CHECK-NEXT: jh {{\.L.*}}
+; CHECK: ldr %f0, %f2
+; CHECK: br %r14
+ %unext = load i32 *%ptr
+ %i1 = zext i32 %unext to i64
+ %cond = icmp ult i64 %i1, %i2
+ %res = select i1 %cond, double %a, double %b
+ ret double %res
+}