[PATCH] D33957: [GlobalISel][X86] Support vector type G_EXTRACT selection.

[Guy Blank via Phabricator via llvm-commits]

guyblank added inline comments.


================
Comment at: lib/Target/X86/X86InstructionSelector.cpp:706
+    // Replace by extract subreg copy.
+    if (!emitExtractSubreg(DstReg, SrcReg, I, MRI, MF))
+      return false;
----------------
does it make sense not to give up here?

not sure when the emit would fail, but we could try to generate a vextract instead.


================
Comment at: lib/Target/X86/X86InstructionSelector.cpp:717
+
+  if (SrcTy.getSizeInBits() == 256 && DstTy.getSizeInBits() == 128) {
+    if (HasVLX)
----------------
```
if(..)
  return false;
```


https://reviews.llvm.org/D33957