[CodeGen] Remove dead hack for MIPS #148039
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@llvm/pr-subscribers-backend-mips @llvm/pr-subscribers-llvm-regalloc Author: AZero13 (AZero13) ChangesAll tests pass without it now. Full diff: https://github.com/llvm/llvm-project/pull/148039.diff 1 Files Affected:
diff --git a/llvm/lib/CodeGen/LiveVariables.cpp b/llvm/lib/CodeGen/LiveVariables.cpp
index 1f23418642bc6..e857ff665913a 100644
--- a/llvm/lib/CodeGen/LiveVariables.cpp
+++ b/llvm/lib/CodeGen/LiveVariables.cpp
@@ -534,10 +534,6 @@ void LiveVariables::runOnInstr(MachineInstr &MI,
UseRegs.push_back(MOReg);
} else {
assert(MO.isDef());
- // FIXME: We should not remove any dead flags. However the MIPS RDDSP
- // instruction needs it at the moment: http://llvm.org/PR27116.
- if (MOReg.isPhysical() && !MRI->isReserved(MOReg))
- MO.setIsDead(false);
DefRegs.push_back(MOReg);
}
}
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arsenm
reviewed
Jul 10, 2025
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@arsenm Thoughts? |
Are you able to explain why it is no longer needed? The code in MipsSEDAGToDAGISel::processFunctionAfterISel mentioned in http://llvm.org/PR27116 is still present. |
This allows us to remove the hack that requires we remove the dead flag from the physical register.
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✅ With the latest revision this PR passed the C/C++ code formatter. |
topperc
reviewed
Jul 16, 2025
| @@ -1579,6 +1626,10 @@ MipsTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI, | |||
| return emitSTR_W(MI, BB); | |||
| case Mips::STR_D: | |||
| return emitSTR_D(MI, BB); | |||
| case Mips::RDDSP_Pseudo: | |||
There was a problem hiding this comment.
EmitInstrWithCustomerInsert runs later than processFunctionAfterISel. How does this fix the problem?
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All tests pass without it now.