[llvm] 86545bf - [AMDGPU] Simplify loops in SIInsertWaitcnts::generateWaitcntInstBefore

[Jay Foad via llvm-commits]

Author: Jay Foad
Date: 2020-04-30T08:53:12+01:00
New Revision: 86545bf72dceadfd415a3336c6d10388c91d2035

URL: https://github.com/llvm/llvm-project/commit/86545bf72dceadfd415a3336c6d10388c91d2035
DIFF: https://github.com/llvm/llvm-project/commit/86545bf72dceadfd415a3336c6d10388c91d2035.diff

LOG: [AMDGPU] Simplify loops in SIInsertWaitcnts::generateWaitcntInstBefore

The loops over use operands and def operands were mostly identical.
Combine them, and likewise for load memoperands and store memoperands.
NFC.

Added: 
    

Modified: 
    llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp

Removed: 
    


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diff  --git a/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp b/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
index 66e2c4053bb6..5fe0a828382a 100644
--- a/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
+++ b/llvm/lib/Target/AMDGPU/SIInsertWaitcnts.cpp
@@ -948,7 +948,19 @@ bool SIInsertWaitcnts::generateWaitcntInstBefore(
       // emitted.
       // If the source operand was defined by a load, add the s_waitcnt
       // instruction.
+      //
+      // Two cases are handled for destination operands:
+      // 1) If the destination operand was defined by a load, add the s_waitcnt
+      // instruction to guarantee the right WAW order.
+      // 2) If a destination operand that was used by a recent export/store ins,
+      // add s_waitcnt on exp_cnt to guarantee the WAR order.
       for (const MachineMemOperand *Memop : MI.memoperands()) {
+        const Value *Ptr = Memop->getValue();
+        if (Memop->isStore() && SLoadAddresses.count(Ptr)) {
+          addWait(Wait, LGKM_CNT, 0);
+          if (PDT->dominates(MI.getParent(), SLoadAddresses.find(Ptr)->second))
+            SLoadAddresses.erase(Ptr);
+        }
         unsigned AS = Memop->getAddrSpace();
         if (AS != AMDGPUAS::LOCAL_ADDRESS)
           continue;
@@ -956,70 +968,32 @@ bool SIInsertWaitcnts::generateWaitcntInstBefore(
         // VM_CNT is only relevant to vgpr or LDS.
         ScoreBrackets.determineWait(
             VM_CNT, ScoreBrackets.getRegScore(RegNo, VM_CNT), Wait);
-      }
-
-      for (unsigned I = 0, E = MI.getNumOperands(); I != E; ++I) {
-        const MachineOperand &Op = MI.getOperand(I);
-        if (!Op.isReg())
-          continue;
-        RegInterval Interval =
-            ScoreBrackets.getRegInterval(&MI, TII, MRI, TRI, I);
-        for (signed RegNo = Interval.first; RegNo < Interval.second; ++RegNo) {
-          if (TRI->isVGPR(*MRI, Op.getReg())) {
-            // VM_CNT is only relevant to vgpr or LDS.
-            ScoreBrackets.determineWait(
-                VM_CNT, ScoreBrackets.getRegScore(RegNo, VM_CNT), Wait);
-          }
-          ScoreBrackets.determineWait(
-              LGKM_CNT, ScoreBrackets.getRegScore(RegNo, LGKM_CNT), Wait);
-        }
-      }
-      // End of for loop that looks at all source operands to decide vm_wait_cnt
-      // and lgk_wait_cnt.
-
-      // Two cases are handled for destination operands:
-      // 1) If the destination operand was defined by a load, add the s_waitcnt
-      // instruction to guarantee the right WAW order.
-      // 2) If a destination operand that was used by a recent export/store ins,
-      // add s_waitcnt on exp_cnt to guarantee the WAR order.
-      if (MI.mayStore()) {
-        // FIXME: Should not be relying on memoperands.
-        for (const MachineMemOperand *Memop : MI.memoperands()) {
-          const Value *Ptr = Memop->getValue();
-          if (SLoadAddresses.count(Ptr)) {
-            addWait(Wait, LGKM_CNT, 0);
-            if (PDT->dominates(MI.getParent(),
-                               SLoadAddresses.find(Ptr)->second))
-              SLoadAddresses.erase(Ptr);
-          }
-          unsigned AS = Memop->getAddrSpace();
-          if (AS != AMDGPUAS::LOCAL_ADDRESS)
-            continue;
-          unsigned RegNo = SQ_MAX_PGM_VGPRS + EXTRA_VGPR_LDS;
-          ScoreBrackets.determineWait(
-              VM_CNT, ScoreBrackets.getRegScore(RegNo, VM_CNT), Wait);
+        if (Memop->isStore()) {
           ScoreBrackets.determineWait(
               EXP_CNT, ScoreBrackets.getRegScore(RegNo, EXP_CNT), Wait);
         }
       }
 
+      // Loop over use and def operands.
       for (unsigned I = 0, E = MI.getNumOperands(); I != E; ++I) {
-        MachineOperand &Def = MI.getOperand(I);
-        if (!Def.isReg() || !Def.isDef())
+        MachineOperand &Op = MI.getOperand(I);
+        if (!Op.isReg())
           continue;
         RegInterval Interval =
             ScoreBrackets.getRegInterval(&MI, TII, MRI, TRI, I);
         for (signed RegNo = Interval.first; RegNo < Interval.second; ++RegNo) {
-          if (TRI->isVGPR(*MRI, Def.getReg())) {
+          if (TRI->isVGPR(*MRI, Op.getReg())) {
             ScoreBrackets.determineWait(
                 VM_CNT, ScoreBrackets.getRegScore(RegNo, VM_CNT), Wait);
-            ScoreBrackets.determineWait(
-                EXP_CNT, ScoreBrackets.getRegScore(RegNo, EXP_CNT), Wait);
+            if (Op.isDef()) {
+              ScoreBrackets.determineWait(
+                  EXP_CNT, ScoreBrackets.getRegScore(RegNo, EXP_CNT), Wait);
+            }
           }
           ScoreBrackets.determineWait(
               LGKM_CNT, ScoreBrackets.getRegScore(RegNo, LGKM_CNT), Wait);
         }
-      } // End of for loop that looks at all dest operands.
+      }
     }
   }