[llvm] r278416 - [Hexagon] Allow non-returning calls in hardware loops

[Krzysztof Parzyszek via llvm-commits]

Author: kparzysz
Date: Thu Aug 11 16:14:25 2016
New Revision: 278416

URL: http://llvm.org/viewvc/llvm-project?rev=278416&view=rev
Log:
[Hexagon] Allow non-returning calls in hardware loops

Added:
    llvm/trunk/test/CodeGen/Hexagon/hwloop-noreturn-call.ll
Modified:
    llvm/trunk/lib/Target/Hexagon/HexagonHardwareLoops.cpp
    llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.cpp
    llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.h

Modified: llvm/trunk/lib/Target/Hexagon/HexagonHardwareLoops.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonHardwareLoops.cpp?rev=278416&r1=278415&r2=278416&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonHardwareLoops.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonHardwareLoops.cpp Thu Aug 11 16:14:25 2016
@@ -962,8 +962,8 @@ bool HexagonHardwareLoops::isInvalidLoop
 
   // Call is not allowed because the callee may use a hardware loop except for
   // the case when the call never returns.
-  if (MI->getDesc().isCall() && MI->getOpcode() != Hexagon::CALLv3nr)
-    return true;
+  if (MI->getDesc().isCall())
+    return !TII->doesNotReturn(*MI);
 
   // Check if the instruction defines a hardware loop register.
   for (unsigned i = 0, e = MI->getNumOperands(); i != e; ++i) {

Modified: llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.cpp?rev=278416&r1=278415&r2=278416&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.cpp (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.cpp Thu Aug 11 16:14:25 2016
@@ -2972,6 +2972,12 @@ bool HexagonInstrInfo::canExecuteInBundl
 }
 
 
+bool HexagonInstrInfo::doesNotReturn(const MachineInstr &CallMI) const {
+  unsigned Opc = CallMI.getOpcode();
+  return Opc == Hexagon::CALLv3nr || Opc == Hexagon::CALLRv3nr;
+}
+
+
 bool HexagonInstrInfo::hasEHLabel(const MachineBasicBlock *B) const {
   for (auto &I : *B)
     if (I.isEHLabel())

Modified: llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.h?rev=278416&r1=278415&r2=278416&view=diff
==============================================================================
--- llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.h (original)
+++ llvm/trunk/lib/Target/Hexagon/HexagonInstrInfo.h Thu Aug 11 16:14:25 2016
@@ -360,6 +360,7 @@ public:
                             const MachineInstr &MI2) const;
   bool canExecuteInBundle(const MachineInstr &First,
                           const MachineInstr &Second) const;
+  bool doesNotReturn(const MachineInstr &CallMI) const;
   bool hasEHLabel(const MachineBasicBlock *B) const;
   bool hasNonExtEquivalent(const MachineInstr &MI) const;
   bool hasPseudoInstrPair(const MachineInstr &MI) const;

Added: llvm/trunk/test/CodeGen/Hexagon/hwloop-noreturn-call.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/Hexagon/hwloop-noreturn-call.ll?rev=278416&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/Hexagon/hwloop-noreturn-call.ll (added)
+++ llvm/trunk/test/CodeGen/Hexagon/hwloop-noreturn-call.ll Thu Aug 11 16:14:25 2016
@@ -0,0 +1,63 @@
+; RUN: llc -march=hexagon < %s | FileCheck %s
+
+target triple = "hexagon"
+
+; CHECK-LABEL: danny:
+; CHECK-DAG: loop0
+; CHECK-DAG: call trap
+define void @danny(i32* %p, i32 %n, i32 %k) #0 {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry
+  %t0 = phi i32 [ 0, %entry ], [ %t1, %for.cont ]
+  %t1 = add i32 %t0, 1
+  %t2 = getelementptr i32, i32* %p, i32 %t0
+  store i32 %t1, i32* %t2, align 4
+  %c = icmp sgt i32 %t1, %k
+  br i1 %c, label %noret, label %for.cont
+
+for.cont:
+  %cmp = icmp slt i32 %t0, %n
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.cond
+  ret void
+
+noret:
+  call void @trap() #1
+  br label %for.cont
+}
+
+; CHECK-LABEL: sammy:
+; CHECK-DAG: loop0
+; CHECK-DAG: callr
+define void @sammy(i32* %p, i32 %n, i32 %k, void (...)* %f) #0 {
+entry:
+  br label %for.body
+
+for.body:                                         ; preds = %entry
+  %t0 = phi i32 [ 0, %entry ], [ %t1, %for.cont ]
+  %t1 = add i32 %t0, 1
+  %t2 = getelementptr i32, i32* %p, i32 %t0
+  store i32 %t1, i32* %t2, align 4
+  %c = icmp sgt i32 %t1, %k
+  br i1 %c, label %noret, label %for.cont
+
+for.cont:
+  %cmp = icmp slt i32 %t0, %n
+  br i1 %cmp, label %for.body, label %for.end
+
+for.end:                                          ; preds = %for.cond
+  ret void
+
+noret:
+  call void (...) %f() #1
+  br label %for.cont
+}
+
+declare void @trap() #1
+
+attributes #0 = { nounwind "target-cpu"="hexagonv60" "target-features"="+hvx,-hvx-double" }
+attributes #1 = { nounwind noreturn }
+