[PATCH] D131117: [X86] Teach PostprocessISelDAG to fold ANDrm+TESTrr when chain result is used.

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/X86/X86ISelDAGToDAG.cpp:1490
         N->getOperand(0) == N->getOperand(1) &&
-        N->isOnlyUserOf(N->getOperand(0).getNode()) &&
+        N->getOperand(0)->hasNUsesOfValue(2, N->getOperand(0).getResNo()) &&
         N->getOperand(0).isMachineOpcode()) {
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LuoYuanke wrote:
> `AND32rm` has 3 output. This check 1st output, should we also check 2nd output (EFLAGS) and only leave the 3rd (chain) output be used freely?
See line 1496 and 1507. We have to check the opcode before we can tell if output 1 exists.


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https://reviews.llvm.org/D131117