[RISCV] Don't merge pseudo selects with stack adjustment instrs in between (#160105)

When we have sequence of select pseudo instructions with stack adjustment
instructions in between, we shouldn't apply the optimization, proposed by link 
https://reviews.llvm.org/D59355. If optimization is applied, 
function won't be marked `adjustsStack` during Finalize ISel pass.

1 files changed, 6 insertions, 2 deletions

diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 937213bfddfa..1ae5cb5730dc 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -22274,6 +22274,7 @@ static MachineBasicBlock *emitSelectPseudo(MachineInstr &MI,
   // - They are debug instructions. Otherwise,
   // - They do not have side-effects, do not access memory and their inputs do
   //   not depend on the results of the select pseudo-instructions.
+  // - They don't adjust stack.
   // The TrueV/FalseV operands of the selects cannot depend on the result of
   // previous selects in the sequence.
   // These conditions could be further relaxed. See the X86 target for a
@@ -22302,6 +22303,8 @@ static MachineBasicBlock *emitSelectPseudo(MachineInstr &MI,
   SelectDests.insert(MI.getOperand(0).getReg());
 
   MachineInstr *LastSelectPseudo = &MI;
+  const RISCVInstrInfo &TII = *Subtarget.getInstrInfo();
+
   for (auto E = BB->end(), SequenceMBBI = MachineBasicBlock::iterator(MI);
        SequenceMBBI != E; ++SequenceMBBI) {
     if (SequenceMBBI->isDebugInstr())
@@ -22321,7 +22324,9 @@ static MachineBasicBlock *emitSelectPseudo(MachineInstr &MI,
     }
     if (SequenceMBBI->hasUnmodeledSideEffects() ||
         SequenceMBBI->mayLoadOrStore() ||
-        SequenceMBBI->usesCustomInsertionHook())
+        SequenceMBBI->usesCustomInsertionHook() ||
+        TII.isFrameInstr(*SequenceMBBI) ||
+        SequenceMBBI->isStackAligningInlineAsm())
       break;
     if (llvm::any_of(SequenceMBBI->operands(), [&](MachineOperand &MO) {
           return MO.isReg() && MO.isUse() && SelectDests.count(MO.getReg());
@@ -22329,7 +22334,6 @@ static MachineBasicBlock *emitSelectPseudo(MachineInstr &MI,
       break;
   }
 
-  const RISCVInstrInfo &TII = *Subtarget.getInstrInfo();
   const BasicBlock *LLVM_BB = BB->getBasicBlock();
   DebugLoc DL = MI.getDebugLoc();
   MachineFunction::iterator I = ++BB->getIterator();