R600/SI: Use VALU instructions for copying i1 values

We can't use SALU instructions for this since they ignore the EXEC mask
and are always executed.

This fixes several OpenCV tests.

llvm-svn: 207661

1 files changed, 130 insertions, 0 deletions

diff --git a/llvm/lib/Target/R600/SILowerI1Copies.cpp b/llvm/lib/Target/R600/SILowerI1Copies.cpp
new file mode 100644
index 00000000000..766380ead58
--- /dev/null
+++ b/llvm/lib/Target/R600/SILowerI1Copies.cpp
@@ -0,0 +1,130 @@
+//===-- SILowerI1Copies.cpp - Lower I1 Copies -----------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+/// i1 values are usually inserted by the CFG Structurize pass and they are
+/// unique in that they can be copied from VALU to SALU registers.
+/// This is not possible for any other value type.  Since there are no
+/// MOV instructions for i1, we to use V_CMP_* and V_CNDMASK to move the i1.
+///
+//===----------------------------------------------------------------------===//
+//
+
+#define DEBUG_TYPE "si-i1-copies"
+#include "AMDGPU.h"
+#include "SIInstrInfo.h"
+#include "llvm/CodeGen/LiveIntervalAnalysis.h"
+#include "llvm/CodeGen/MachineDominators.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Function.h"
+#include "llvm/Support/Debug.h"
+#include "llvm/Target/TargetMachine.h"
+
+using namespace llvm;
+
+namespace {
+
+class SILowerI1Copies : public MachineFunctionPass {
+public:
+  static char ID;
+
+public:
+  SILowerI1Copies() : MachineFunctionPass(ID) {
+    initializeSILowerI1CopiesPass(*PassRegistry::getPassRegistry());
+  }
+
+  virtual bool runOnMachineFunction(MachineFunction &MF) override;
+
+  virtual const char *getPassName() const override {
+    return "SI Lower il Copies";
+  }
+
+  virtual void getAnalysisUsage(AnalysisUsage &AU) const override {
+  AU.addRequired<MachineDominatorTree>();
+    AU.setPreservesCFG();
+    MachineFunctionPass::getAnalysisUsage(AU);
+  }
+};
+
+} // End anonymous namespace.
+
+INITIALIZE_PASS_BEGIN(SILowerI1Copies, DEBUG_TYPE,
+                      "SI Lower il Copies", false, false)
+INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
+INITIALIZE_PASS_END(SILowerI1Copies, DEBUG_TYPE,
+                    "SI Lower il Copies", false, false)
+
+char SILowerI1Copies::ID = 0;
+
+char &llvm::SILowerI1CopiesID = SILowerI1Copies::ID;
+
+FunctionPass *llvm::createSILowerI1CopiesPass() {
+  return new SILowerI1Copies();
+}
+
+bool SILowerI1Copies::runOnMachineFunction(MachineFunction &MF) {
+  MachineRegisterInfo &MRI = MF.getRegInfo();
+  const SIInstrInfo *TII = static_cast<const SIInstrInfo *>(
+      MF.getTarget().getInstrInfo());
+  const TargetRegisterInfo *TRI = MF.getTarget().getRegisterInfo();
+
+  for (MachineFunction::iterator BI = MF.begin(), BE = MF.end();
+                                                  BI != BE; ++BI) {
+
+    MachineBasicBlock &MBB = *BI;
+    MachineBasicBlock::iterator I, Next;
+    for (I = MBB.begin(); I != MBB.end(); I = Next) {
+      Next = std::next(I);
+      MachineInstr &MI = *I;
+
+      if (MI.getOpcode() == AMDGPU::V_MOV_I1) {
+        MI.setDesc(TII->get(AMDGPU::V_MOV_B32_e32));
+        continue;
+      }
+
+      if (MI.getOpcode() != AMDGPU::COPY ||
+          !TargetRegisterInfo::isVirtualRegister(MI.getOperand(0).getReg()) ||
+          !TargetRegisterInfo::isVirtualRegister(MI.getOperand(1).getReg()))
+        continue;
+
+
+      const TargetRegisterClass *DstRC =
+          MRI.getRegClass(MI.getOperand(0).getReg());
+      const TargetRegisterClass *SrcRC =
+          MRI.getRegClass(MI.getOperand(1).getReg());
+
+      if (DstRC == &AMDGPU::VReg_1RegClass &&
+          TRI->getCommonSubClass(SrcRC, &AMDGPU::SGPR_64RegClass)) {
+        BuildMI(MBB, &MI, MI.getDebugLoc(), TII->get(AMDGPU::V_CNDMASK_B32_e64))
+                .addOperand(MI.getOperand(0))
+                .addImm(0)
+                .addImm(-1)
+                .addOperand(MI.getOperand(1))
+                .addImm(0)
+                .addImm(0)
+                .addImm(0)
+                .addImm(0);
+        MI.eraseFromParent();
+      } else if (TRI->getCommonSubClass(DstRC, &AMDGPU::SGPR_64RegClass) &&
+                 SrcRC == &AMDGPU::VReg_1RegClass) {
+        BuildMI(MBB, &MI, MI.getDebugLoc(), TII->get(AMDGPU::V_CMP_NE_I32_e64))
+                .addOperand(MI.getOperand(0))
+                .addImm(0)
+                .addOperand(MI.getOperand(1))
+                .addImm(0)
+                .addImm(0)
+                .addImm(0)
+                .addImm(0);
+        MI.eraseFromParent();
+      }
+
+    }
+  }
+  return false;
+}