Making Zalasr lowering match the psABI (aka lb.aqrl and sb.aqrl are no longer used in the lowering)

Author: Brendan Sweeney

llvm/lib/Target/RISCV/RISCVISelLowering.cpp

@@ -20506,12 +20506,12 @@ unsigned RISCVTargetLowering::getCustomCtpopCost(EVT VT,
   return isCtpopFast(VT) ? 0 : 1;
 }
 
-bool RISCVTargetLowering::shouldInsertFencesForAtomic(const Instruction *I) const {
+bool RISCVTargetLowering::shouldInsertFencesForAtomic(
+    const Instruction *I) const {
   if (Subtarget.hasStdExtZalasr()) {
     return false;
-  } else {
-    return isa<LoadInst>(I) || isa<StoreInst>(I);
   }
+  return isa<LoadInst>(I) || isa<StoreInst>(I);
 }
 
 bool RISCVTargetLowering::fallBackToDAGISel(const Instruction &Inst) const {

llvm/lib/Target/RISCV/RISCVInstrInfoZalasr.td

@@ -71,28 +71,28 @@ class PatSRL<SDPatternOperator OpNode, RVInst Inst, ValueType vt = XLenVT>
 
 let Predicates = [HasStdExtZalasr] in {
   def : PatLAQ<acquiring_load<atomic_load_8>, LB_AQ_AQ>;
-  def : PatLAQ<seq_cst_load<atomic_load_8>, LB_AQ_AQ_RL>;
+  def : PatLAQ<seq_cst_load<atomic_load_8>, LB_AQ_AQ>; // these use lb.aq instead of lb.aqrl to match the psABI
 
   def : PatLAQ<acquiring_load<atomic_load_16>, LH_AQ_AQ>;
-  def : PatLAQ<seq_cst_load<atomic_load_16>, LH_AQ_AQ_RL>;
+  def : PatLAQ<seq_cst_load<atomic_load_16>, LH_AQ_AQ>;
 
   def : PatLAQ<acquiring_load<atomic_load_32>, LW_AQ_AQ>;
-  def : PatLAQ<seq_cst_load<atomic_load_32>, LW_AQ_AQ_RL>;
+  def : PatLAQ<seq_cst_load<atomic_load_32>, LW_AQ_AQ>;
 
   def : PatSRL<releasing_store<atomic_store_8>, SB_RL_RL>;
-  def : PatSRL<seq_cst_store<atomic_store_8>, SB_RL_AQ_RL>;
+  def : PatSRL<seq_cst_store<atomic_store_8>, SB_RL_RL>; // these use sb.rl instead of sb.aqrl to match the psABI
 
   def : PatSRL<releasing_store<atomic_store_16>, SH_RL_RL>;
-  def : PatSRL<seq_cst_store<atomic_store_16>, SH_RL_AQ_RL>;
+  def : PatSRL<seq_cst_store<atomic_store_16>, SH_RL_RL>;
 
   def : PatSRL<releasing_store<atomic_store_32>, SW_RL_RL>;
-  def : PatSRL<seq_cst_store<atomic_store_32>, SW_RL_AQ_RL>;
+  def : PatSRL<seq_cst_store<atomic_store_32>, SW_RL_RL>;
 } // Predicates HasStdExtZalasr
 
 let Predicates = [HasStdExtZalasr, IsRV64] in {
   def : PatLAQ<acquiring_load<atomic_load_64>, LD_AQ_AQ>;
-  def : PatLAQ<seq_cst_load<atomic_load_64>, LD_AQ_AQ_RL>;
+  def : PatLAQ<seq_cst_load<atomic_load_64>, LD_AQ_AQ>;
 
   def : PatSRL<releasing_store<atomic_store_64>, SD_RL_RL>;
-  def : PatSRL<seq_cst_store<atomic_store_64>, SD_RL_AQ_RL>;
+  def : PatSRL<seq_cst_store<atomic_store_64>, SD_RL_RL>;
 } // Predicates HasStdExtZalasr, IsRV64