Commit 4a06abc7 authored by Tom Stellard's avatar Tom Stellard
Browse files

Merging r260692: 

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r260692 | changpeng.fang | 2016-02-12 09:11:04 -0800 (Fri, 12 Feb 2016) | 13 lines

AMDGPU/SI: Annotate Loops with Constant Condition in SIAnnotateControlFlow pass.

Summary:
  It is possible that the loop condition can be a boolean constant (infinite loop,
for example). So we sould handle constant condition in annotating a loop. This
patch adds this functionality to support annotating constant condition.

Reviewers: tstellarAMD, arsenm

Subscribers: llvm-commits, arsenm

Differential Revision: http://reviews.llvm.org/D15093

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llvm-svn: 271685
parent 44ec90ba

llvm/lib/Target/AMDGPU/SIAnnotateControlFlow.cpp

+10 −4
Original line number Diff line number Diff line
@@ -81,7 +81,8 @@ class SIAnnotateControlFlow : public FunctionPass { 


  void insertElse(BranchInst *Term);



  Value *handleLoopCondition(Value *Cond, PHINode *Broken, llvm::Loop *L);

  Value *handleLoopCondition(Value *Cond, PHINode *Broken,

                             llvm::Loop *L, BranchInst *Term);



  void handleLoop(BranchInst *Term);
@@ -213,7 +214,7 @@ void SIAnnotateControlFlow::insertElse(BranchInst *Term) { 


/// \brief Recursively handle the condition leading to a loop

Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken,

                                                  llvm::Loop *L) {

                                             llvm::Loop *L, BranchInst *Term) {



  // Only search through PHI nodes which are inside the loop.  If we try this

  // with PHI nodes that are outside of the loop, we end up inserting new PHI
@@ -237,7 +238,7 @@ Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken, 
      }



      Phi->setIncomingValue(i, BoolFalse);

      Value *PhiArg = handleLoopCondition(Incoming, Broken, L);

      Value *PhiArg = handleLoopCondition(Incoming, Broken, L, Term);

      NewPhi->addIncoming(PhiArg, From);

    }
@@ -276,6 +277,11 @@ Value *SIAnnotateControlFlow::handleLoopCondition(Value *Cond, PHINode *Broken, 
    Value *Args[] = { Cond, Broken };

    return CallInst::Create(IfBreak, Args, "", Insert);



  // Insert IfBreak before TERM for constant COND.

  } else if (isa<ConstantInt>(Cond)) {

    Value *Args[] = { Cond, Broken };

    return CallInst::Create(IfBreak, Args, "", Term);



  } else {

    llvm_unreachable("Unhandled loop condition!");

  }
@@ -291,7 +297,7 @@ void SIAnnotateControlFlow::handleLoop(BranchInst *Term) { 


  Value *Cond = Term->getCondition();

  Term->setCondition(BoolTrue);

  Value *Arg = handleLoopCondition(Cond, Broken, L);

  Value *Arg = handleLoopCondition(Cond, Broken, L, Term);



  for (pred_iterator PI = pred_begin(Target), PE = pred_end(Target);

       PI != PE; ++PI) {

llvm/test/CodeGen/AMDGPU/si-annotate-cfg-loop-assert.ll

0 → 100644
+24 −0
Original line number Diff line number Diff line 
; RUN: llc -march=amdgcn -mcpu=kaveri  < %s | FileCheck %s



; CHECK-LABEL: {{^}}test:

; CHECK s_and_saveexec_b64

; CHECK s_xor_b64

; CHECK s_or_b64 exec, exec

; CHECK s_andn2_b64 exec, exec

; CHECK s_cbranch_execnz

define spir_kernel void @test(i32 %arg, i32 %arg1, i32 addrspace(1)* nocapture %arg2, i32 %arg3, i32 %arg4, i32 %arg5, i32 %arg6) {

bb:

  %tmp = icmp ne i32 %arg, 0

  %tmp7 = icmp ne i32 %arg1, 0

  %tmp8 = and i1 %tmp, %tmp7

  br i1 %tmp8, label %bb9, label %bb11



bb9:                                              ; preds = %bb

  br label %bb10



bb10:                                             ; preds = %bb10, %bb9

  br label %bb10



bb11:                                             ; preds = %bb

  ret void

}