[ARM] CMOV->BFI combining: handle both senses of CMPZ
I completely misunderstood what ARMISD::CMPZ means. It's not "compare equal to zero", it's "compare, only setting the zero/Z flag". It can either be equal-to-zero or not-equal-to-zero, and we weren't checking what sense it was.
If it's equal-to-zero, we can swap the operands around and pretend like it is not-equal-to-zero, which is both a bug fix and lets us handle more cases.
llvm-svn: 252891
diff --git a/llvm/test/CodeGen/ARM/bfi.ll b/llvm/test/CodeGen/ARM/bfi.ll
index 7699527..39bcbf2 100644
--- a/llvm/test/CodeGen/ARM/bfi.ll
+++ b/llvm/test/CodeGen/ARM/bfi.ll
@@ -147,3 +147,14 @@
ret i32 %bsel
}
+
+define i32 @f12(i32 %x, i32 %y) {
+; CHECK-LABEL: f12:
+; CHECK: bfi r1, r0, #4, #1
+ %y2 = and i32 %y, 4294967040 ; 0xFFFFFF00
+ %and = and i32 %x, 4
+ %or = or i32 %y2, 16
+ %cmp = icmp eq i32 %and, 0
+ %sel = select i1 %cmp, i32 %y2, i32 %or
+ ret i32 %sel
+}