Merge commit '5eef98ba319a' from llvm.org/main into next

Author: git apple-llvm automerger

llvm/include/llvm/CodeGen/SlotIndexes.h

@@ -467,16 +467,27 @@ class raw_ostream;
       return getMBBRange(mbb).first;
     }
 
-    /// Returns the last index in the given basic block number.
+    /// Returns the index past the last valid index in the given basic block.
     SlotIndex getMBBEndIdx(unsigned Num) const {
       return getMBBRange(Num).second;
     }
 
-    /// Returns the last index in the given basic block.
+    /// Returns the index past the last valid index in the given basic block.
     SlotIndex getMBBEndIdx(const MachineBasicBlock *mbb) const {
       return getMBBRange(mbb).second;
     }
 
+    /// Returns the last valid index in the given basic block.
+    /// This index corresponds to the dead slot of the last non-debug
+    /// instruction and can be used to find live-out ranges of the block. Note
+    /// that getMBBEndIdx returns the start index of the next block, which is
+    /// also used as the start index for segments with phi-def values. If the
+    /// basic block doesn't contain any non-debug instructions, this returns
+    /// the same as getMBBStartIdx.getDeadSlot().
+    SlotIndex getMBBLastIdx(const MachineBasicBlock *MBB) const {
+      return getMBBEndIdx(MBB).getPrevSlot();
+    }
+
     /// Iterator over the idx2MBBMap (sorted pairs of slot index of basic block
     /// begin and basic block)
     using MBBIndexIterator = SmallVectorImpl<IdxMBBPair>::const_iterator;

llvm/lib/Target/AMDGPU/GCNRegPressure.cpp

@@ -905,7 +905,7 @@ bool GCNRegPressurePrinter::runOnMachineFunction(MachineFunction &MF) {
     OS << ":\n";
 
     SlotIndex MBBStartSlot = LIS.getSlotIndexes()->getMBBStartIdx(&MBB);
-    SlotIndex MBBEndSlot = LIS.getSlotIndexes()->getMBBEndIdx(&MBB);
+    SlotIndex MBBLastSlot = LIS.getSlotIndexes()->getMBBLastIdx(&MBB);
 
     GCNRPTracker::LiveRegSet LiveIn, LiveOut;
     GCNRegPressure RPAtMBBEnd;
@@ -931,7 +931,7 @@ bool GCNRegPressurePrinter::runOnMachineFunction(MachineFunction &MF) {
       }
     } else {
       GCNUpwardRPTracker RPT(LIS);
-      RPT.reset(MRI, MBBEndSlot);
+      RPT.reset(MRI, MBBLastSlot);
 
       LiveOut = RPT.getLiveRegs();
       RPAtMBBEnd = RPT.getPressure();
@@ -966,14 +966,14 @@ bool GCNRegPressurePrinter::runOnMachineFunction(MachineFunction &MF) {
 
     OS << PFX "  Live-out:" << llvm::print(LiveOut, MRI);
     if (UseDownwardTracker)
-      ReportLISMismatchIfAny(LiveOut, getLiveRegs(MBBEndSlot, LIS, MRI));
+      ReportLISMismatchIfAny(LiveOut, getLiveRegs(MBBLastSlot, LIS, MRI));
 
     GCNRPTracker::LiveRegSet LiveThrough;
     for (auto [Reg, Mask] : LiveIn) {
       LaneBitmask MaskIntersection = Mask & LiveOut.lookup(Reg);
       if (MaskIntersection.any()) {
         LaneBitmask LTMask = getRegLiveThroughMask(
-            MRI, LIS, Reg, MBBStartSlot, MBBEndSlot, MaskIntersection);
+            MRI, LIS, Reg, MBBStartSlot, MBBLastSlot, MaskIntersection);
         if (LTMask.any())
           LiveThrough[Reg] = LTMask;
       }

llvm/lib/Target/AMDGPU/GCNRegPressure.h

@@ -313,8 +313,8 @@ class GCNUpwardRPTracker : public GCNRPTracker {
 
   /// reset tracker to the end of the \p MBB.
   void reset(const MachineBasicBlock &MBB) {
-    reset(MBB.getParent()->getRegInfo(),
-          LIS.getSlotIndexes()->getMBBEndIdx(&MBB));
+    SlotIndex MBBLastSlot = LIS.getSlotIndexes()->getMBBLastIdx(&MBB);
+    reset(MBB.getParent()->getRegInfo(), MBBLastSlot);
   }
 
   /// reset tracker to the point just after \p MI (in program order).

llvm/test/CodeGen/AMDGPU/regpressure_printer.mir

@@ -510,14 +510,14 @@ body: |
   ; RPU-NEXT:   0     0      $sgpr0 = S_BUFFER_LOAD_DWORD_IMM $sgpr0_sgpr1_sgpr2_sgpr3, 0, 0
   ; RPU-NEXT:   0     0
   ; RPU-NEXT:   0     1      undef %0.sub5:vreg_512 = V_MOV_B32_e32 5, implicit $exec
-  ; RPU-NEXT:   0     0
-  ; RPU-NEXT:   0     0      S_CMP_GT_U32 $sgpr0, 15, implicit-def $scc
-  ; RPU-NEXT:   0     0
-  ; RPU-NEXT:   0     0      S_CBRANCH_SCC1 %bb.2, implicit $scc
-  ; RPU-NEXT:   0     0
-  ; RPU-NEXT:   0     0      S_BRANCH %bb.1
-  ; RPU-NEXT:   0     0
-  ; RPU-NEXT:   Live-out:
+  ; RPU-NEXT:   0     1
+  ; RPU-NEXT:   0     1      S_CMP_GT_U32 $sgpr0, 15, implicit-def $scc
+  ; RPU-NEXT:   0     1
+  ; RPU-NEXT:   0     1      S_CBRANCH_SCC1 %bb.2, implicit $scc
+  ; RPU-NEXT:   0     1
+  ; RPU-NEXT:   0     1      S_BRANCH %bb.1
+  ; RPU-NEXT:   0     1
+  ; RPU-NEXT:   Live-out: %0:0000000000000C00
   ; RPU-NEXT:   Live-thr:
   ; RPU-NEXT:   0     0
   ; RPU-NEXT: bb.1:
@@ -571,8 +571,6 @@ body: |
   ; RPD-NEXT:   0     1      S_BRANCH %bb.1
   ; RPD-NEXT:   0     1
   ; RPD-NEXT:   Live-out: %0:0000000000000C00
-  ; RPD-NEXT:   mis LIS:
-  ; RPD-NEXT:     %0:L0000000000000C00 isn't found in LIS reported set
   ; RPD-NEXT:   Live-thr:
   ; RPD-NEXT:   0     0
   ; RPD-NEXT: bb.1: