[PATCH] prevent folding a scalar FP load into a packed logical FP instruction (PR22371)

[Sanjay Patel]

================
Comment at: test/CodeGen/X86/stack-align-vector-load.ll:11
@@ +10,3 @@
+; stack must be part of the { double, double } struct, so it should be safe to read
+; the extra bytes, but we need to teach the backend to recognize this case. 
+
----------------
qcolombet wrote:
> Following the logic that reading undef is evil, shouldn't we just make sure that indeed this test is failing to fold?
Yes, that would be the safer thing, and there's very little upside in folding an FP logic load, so this optimization would probably remain XFAIL forever.

I'll update the patch with this change.

http://reviews.llvm.org/D7474

EMAIL PREFERENCES
  http://reviews.llvm.org/settings/panel/emailpreferences/