[llvm] [X86] Resolve FIXME: Add FPCW as a rounding control register (PR #82452)

[via llvm-commits]

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@@ -115,7 +115,9 @@ bool WaitInsert::runOnMachineFunction(MachineFunction &MF) {
       // If the following instruction is an X87 instruction and isn't an X87
       // non-waiting control instruction, we can omit insert wait instruction.
       MachineBasicBlock::iterator AfterMI = std::next(MI);
-      if (AfterMI != MBB.end() && X86::isX87Instruction(*AfterMI) &&
+      if (AfterMI != MBB.end() && !AfterMI->isCall() &&
+          !AfterMI->isTerminator() && !AfterMI->isReturn() &&
+          !AfterMI->isInlineAsm() && X86::isX87Instruction(*AfterMI) &&
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AtariDreams wrote:

That is true, but I do not know if we want to do this in every single case (It appears that the x87 register can do more than be a control register)

https://github.com/llvm/llvm-project/pull/82452