[llvm] [InlineSpiller] Check rematerialization before folding operand (PR #134015)

[via llvm-commits]

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@@ -615,6 +620,23 @@ bool InlineSpiller::canGuaranteeAssignmentAfterRemat(Register VReg,
   return true;
 }
 
+/// hasPhysRegAvailable - Check if there is an available physical register for
+/// rematerialization.
+bool InlineSpiller::hasPhysRegAvailable(const MachineInstr &MI) {
+  if (!Order || !Matrix)
+    return false;
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weiguozhi wrote:

The InlineSpiller is used by multiple register allocators, but not all of them use AllocationOrder, so we may not always get a valid Order. Maybe that allocator(PBQP) should be fixed.

https://github.com/llvm/llvm-project/pull/134015