[PATCH] D48970: [DAGCombiner] extend(ifpositive(X)) -> shift-right (not X)

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: test/CodeGen/X86/signbit-shift.ll:74
 ; CHECK:       # %bb.0:
-; CHECK-NEXT:    xorl %ecx, %ecx
-; CHECK-NEXT:    testl %edi, %edi
-; CHECK-NEXT:    setns %cl
+; CHECK-NEXT:    notl %edi
+; CHECK-NEXT:    shrl $31, %edi
----------------
Do you have a longer term plan here?

This looks like it could be something like:

```
shrl $31, %edi
add $41, %edi
mov %edi, %eax
```


https://reviews.llvm.org/D48970