[llvm] r368608 - [X86] Add a paranoia type check to the code that detects AVG patterns from truncating stores.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Mon Aug 12 12:26:37 2019
New Revision: 368608

URL: http://llvm.org/viewvc/llvm-project?rev=368608&view=rev
Log:
[X86] Add a paranoia type check to the code that detects AVG patterns from truncating stores.

If we're after type legalize, we should make sure we won't create
a store with an illegal type when we separate the AVG pattern
from the truncating store.

I don't know of a way to fail for this today. Just noticed while
I was in the vicinity.

Modified:
    llvm/trunk/lib/Target/X86/X86ISelLowering.cpp

Modified: llvm/trunk/lib/Target/X86/X86ISelLowering.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/X86/X86ISelLowering.cpp?rev=368608&r1=368607&r2=368608&view=diff
==============================================================================
--- llvm/trunk/lib/Target/X86/X86ISelLowering.cpp (original)
+++ llvm/trunk/lib/Target/X86/X86ISelLowering.cpp Mon Aug 12 12:26:37 2019
@@ -39617,11 +39617,12 @@ static SDValue combineStore(SDNode *N, S
     // Check if we can detect an AVG pattern from the truncation. If yes,
     // replace the trunc store by a normal store with the result of X86ISD::AVG
     // instruction.
-    if (SDValue Avg = detectAVGPattern(St->getValue(), St->getMemoryVT(), DAG,
-                                       Subtarget, dl))
-      return DAG.getStore(St->getChain(), dl, Avg, St->getBasePtr(),
-                          St->getPointerInfo(), St->getAlignment(),
-                          St->getMemOperand()->getFlags());
+    if (DCI.isBeforeLegalize() || TLI.isTypeLegal(St->getMemoryVT()))
+      if (SDValue Avg = detectAVGPattern(St->getValue(), St->getMemoryVT(), DAG,
+                                         Subtarget, dl))
+        return DAG.getStore(St->getChain(), dl, Avg, St->getBasePtr(),
+                            St->getPointerInfo(), St->getAlignment(),
+                            St->getMemOperand()->getFlags());
 
     if (TLI.isTruncStoreLegal(VT, StVT)) {
       if (SDValue Val = detectSSatPattern(St->getValue(), St->getMemoryVT()))