Subzero: Fix a couple of debugging tools.

src/IceOperand.h

@@ -520,7 +520,7 @@ protected:
   bool IsImplicitArgument = false;
   /// IgnoreLiveness means that the variable should be ignored when constructing
   /// and validating live ranges. This is usually reserved for the stack
-  /// pointer.
+  /// pointer and other physical registers specifically referenced by name.
   bool IgnoreLiveness = false;
   RegRequirement RegRequirement = RR_MayHaveRegister;
   /// RegNum is the allocated register, or NoRegister if it isn't

src/IceRegAlloc.cpp

@@ -339,12 +339,12 @@ void LinearScan::handleActiveRangeExpiredOrInactive(const Variable *Cur) {
     bool Moved = false;
     if (Item->rangeEndsBefore(Cur)) {
       // Move Item from Active to Handled list.
-      dumpLiveRangeTrace("Expiring     ", Cur);
+      dumpLiveRangeTrace("Expiring     ", Item);
       moveItem(Active, Index, Handled);
       Moved = true;
     } else if (!Item->rangeOverlapsStart(Cur)) {
       // Move Item from Active to Inactive list.
-      dumpLiveRangeTrace("Inactivating ", Cur);
+      dumpLiveRangeTrace("Inactivating ", Item);
       moveItem(Active, Index, Inactive);
       Moved = true;
     }
@@ -368,11 +368,11 @@ void LinearScan::handleInactiveRangeExpiredOrReactivated(const Variable *Cur) {
     Item->trimLiveRange(Cur->getLiveRange().getStart());
     if (Item->rangeEndsBefore(Cur)) {
       // Move Item from Inactive to Handled list.
-      dumpLiveRangeTrace("Expiring     ", Cur);
+      dumpLiveRangeTrace("Expiring     ", Item);
       moveItem(Inactive, Index, Handled);
     } else if (Item->rangeOverlapsStart(Cur)) {
       // Move Item from Inactive to Active list.
-      dumpLiveRangeTrace("Reactivating ", Cur);
+      dumpLiveRangeTrace("Reactivating ", Item);
       moveItem(Inactive, Index, Active);
       // Increment Item in RegUses[].
       assert(Item->hasRegTmp());

src/IceTargetLoweringARM32.cpp

@@ -389,12 +389,12 @@ Variable *TargetARM32::getPhysicalRegister(SizeT RegNum, Type Ty) {
     Reg = Func->makeVariable(Ty);
     Reg->setRegNum(RegNum);
     PhysicalRegisters[Ty][RegNum] = Reg;
-    // Specially mark SP and LR as an "argument" so that it is considered live
-    // upon function entry.
-    if (RegNum == RegARM32::Reg_sp || RegNum == RegARM32::Reg_lr) {
-      Func->addImplicitArg(Reg);
-      Reg->setIgnoreLiveness();
-    }
+    // Specially mark a named physical register as an "argument" so that it is
+    // considered live upon function entry.  Otherwise it's possible to get
+    // liveness validation errors for saving callee-save registers.
+    Func->addImplicitArg(Reg);
+    // Don't bother tracking the live range of a named physical register.
+    Reg->setIgnoreLiveness();
   }
   return Reg;
 }

src/IceTargetLoweringMIPS32.cpp

@@ -243,12 +243,12 @@ Variable *TargetMIPS32::getPhysicalRegister(SizeT RegNum, Type Ty) {
     Reg = Func->makeVariable(Ty);
     Reg->setRegNum(RegNum);
     PhysicalRegisters[Ty][RegNum] = Reg;
-    // Specially mark SP as an "argument" so that it is considered live upon
-    // function entry.
-    if (RegNum == RegMIPS32::Reg_SP || RegNum == RegMIPS32::Reg_RA) {
-      Func->addImplicitArg(Reg);
-      Reg->setIgnoreLiveness();
-    }
+    // Specially mark a named physical register as an "argument" so that it is
+    // considered live upon function entry.  Otherwise it's possible to get
+    // liveness validation errors for saving callee-save registers.
+    Func->addImplicitArg(Reg);
+    // Don't bother tracking the live range of a named physical register.
+    Reg->setIgnoreLiveness();
   }
   return Reg;
 }

src/IceTargetLoweringX86BaseImpl.h

@@ -720,12 +720,12 @@ Variable *TargetX86Base<Machine>::getPhysicalRegister(SizeT RegNum, Type Ty) {
     Reg = Func->makeVariable(Ty);
     Reg->setRegNum(RegNum);
     PhysicalRegisters[Ty][RegNum] = Reg;
-    // Specially mark esp as an "argument" so that it is considered live upon
-    // function entry.
-    if (RegNum == Traits::RegisterSet::Reg_esp) {
-      Func->addImplicitArg(Reg);
-      Reg->setIgnoreLiveness();
-    }
+    // Specially mark a named physical register as an "argument" so that it is
+    // considered live upon function entry.  Otherwise it's possible to get
+    // liveness validation errors for saving callee-save registers.
+    Func->addImplicitArg(Reg);
+    // Don't bother tracking the live range of a named physical register.
+    Reg->setIgnoreLiveness();
   }
   return Reg;
 }

tests_lit/llvm2ice_tests/asm-verbose.ll

+; Tests that -asm-verbose doesn't fail liveness validation because of
+; callee-save pushes/pops in a single-basic-block function.
+
+; REQUIRES: allow_dump
+; RUN: %p2i --target x8632 -i %s --filetype=asm --args -O2 -asm-verbose \
+; RUN:   | FileCheck %s
+; TODO(stichnot,jpp): Enable for x8664 and arm32.
+; RUIN: %p2i --target x8664 -i %s --filetype=asm --args -O2 -asm-verbose \
+; RUIN:   | FileCheck %s
+; RUIN: %p2i --target arm32 -i %s --filetype=asm --args -O2 -asm-verbose \
+; RUIN:   | FileCheck %s
+
+define i32 @single_bb(i32 %arg0, i32 %arg1, i32 %arg2, i32 %arg3, i32 %arg4, i32 %arg5, i32 %arg6, i32 %arg7) {
+b1:
+  %t1 = add i32 %arg0, %arg1
+  %t2 = add i32 %t1, %arg2
+  %t3 = add i32 %t2, %arg3
+  %t4 = add i32 %t3, %arg4
+  %t5 = add i32 %t4, %arg5
+  %t6 = add i32 %t5, %arg6
+  %t7 = add i32 %t6, %arg7
+  ret i32 %t7
+}
+
+; CHECK-LABEL: single_bb