[Mesa-dev] [PATCH] AMDGPU: s/flow control/control flow/g in SI code.

Michel Dänzer michel at daenzer.net
Fri Nov 9 07:13:51 PST 2012


From: Michel Dänzer <michel.daenzer at amd.com>


Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---

This patch applies on top of Christian's SGPR liveness patch.

 lib/Target/AMDGPU/AMDGPU.h                |    2 +-
 lib/Target/AMDGPU/AMDGPUTargetMachine.cpp |    2 +-
 lib/Target/AMDGPU/CMakeLists.txt          |    2 +-
 lib/Target/AMDGPU/SIFixSGPRLiveness.cpp   |    2 +-
 lib/Target/AMDGPU/SILowerControlFlow.cpp  |  193 +++++++++++++++++++++++++++++
 lib/Target/AMDGPU/SILowerFlowControl.cpp  |  193 -----------------------------
 6 files changed, 197 insertions(+), 197 deletions(-)
 create mode 100644 lib/Target/AMDGPU/SILowerControlFlow.cpp
 delete mode 100644 lib/Target/AMDGPU/SILowerFlowControl.cpp

diff --git a/lib/Target/AMDGPU/AMDGPU.h b/lib/Target/AMDGPU/AMDGPU.h
index 33a74dc..2a06ade 100644
--- a/lib/Target/AMDGPU/AMDGPU.h
+++ b/lib/Target/AMDGPU/AMDGPU.h
@@ -25,7 +25,7 @@ FunctionPass *createR600ExpandSpecialInstrsPass(TargetMachine &tm);
 
 // SI Passes
 FunctionPass *createSIAssignInterpRegsPass(TargetMachine &tm);
-FunctionPass *createSILowerFlowControlPass(TargetMachine &tm);
+FunctionPass *createSILowerControlFlowPass(TargetMachine &tm);
 FunctionPass *createSICodeEmitterPass(formatted_raw_ostream &OS);
 FunctionPass *createSILowerLiteralConstantsPass(TargetMachine &tm);
 FunctionPass *createSIFixSGPRLivenessPass(TargetMachine &tm);
diff --git a/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp b/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
index 024ff3d..5c4af91 100644
--- a/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
+++ b/lib/Target/AMDGPU/AMDGPUTargetMachine.cpp
@@ -137,7 +137,7 @@ bool AMDGPUPassConfig::addPreEmitPass() {
     addPass(&FinalizeMachineBundlesID);
   } else {
     addPass(createSILowerLiteralConstantsPass(*TM));
-    addPass(createSILowerFlowControlPass(*TM));
+    addPass(createSILowerControlFlowPass(*TM));
   }
 
   return false;
diff --git a/lib/Target/AMDGPU/CMakeLists.txt b/lib/Target/AMDGPU/CMakeLists.txt
index 5e013f6..cd3f174 100644
--- a/lib/Target/AMDGPU/CMakeLists.txt
+++ b/lib/Target/AMDGPU/CMakeLists.txt
@@ -41,7 +41,7 @@ add_llvm_target(AMDGPUCodeGen
   SIInstrInfo.cpp
   SIISelLowering.cpp
   SILowerLiteralConstants.cpp
-  SILowerFlowControl.cpp
+  SILowerControlFlow.cpp
   SIMachineFunctionInfo.cpp
   SIRegisterInfo.cpp
   SIPreColorSGPRs.cpp
diff --git a/lib/Target/AMDGPU/SIFixSGPRLiveness.cpp b/lib/Target/AMDGPU/SIFixSGPRLiveness.cpp
index 028753e..f92eff5 100644
--- a/lib/Target/AMDGPU/SIFixSGPRLiveness.cpp
+++ b/lib/Target/AMDGPU/SIFixSGPRLiveness.cpp
@@ -7,7 +7,7 @@
 //
 //===----------------------------------------------------------------------===//
 //
-// SGPRs are not affected by flow control. This pass adjust SGPR liveness in
+// SGPRs are not affected by control flow. This pass adjust SGPR liveness in
 // so that the register allocator can still correctly allocate them.
 //
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/AMDGPU/SILowerControlFlow.cpp b/lib/Target/AMDGPU/SILowerControlFlow.cpp
new file mode 100644
index 0000000..b43fdeb
--- /dev/null
+++ b/lib/Target/AMDGPU/SILowerControlFlow.cpp
@@ -0,0 +1,193 @@
+//===-- SILowerControlFlow.cpp - Use predicates for control flow ----------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This pass lowers the pseudo control flow instructions (SI_IF_NZ, ELSE, ENDIF)
+// to predicated instructions.
+//
+// All control flow (except loops) is handled using predicated instructions and
+// a predicate stack.  Each Scalar ALU controls the operations of 64 Vector
+// ALUs.  The Scalar ALU can update the predicate for any of the Vector ALUs
+// by writting to the 64-bit EXEC register (each bit corresponds to a
+// single vector ALU).  Typically, for predicates, a vector ALU will write
+// to its bit of the VCC register (like EXEC VCC is 64-bits, one for each
+// Vector ALU) and then the ScalarALU will AND the VCC register with the
+// EXEC to update the predicates.
+//
+// For example:
+// %VCC = V_CMP_GT_F32 %VGPR1, %VGPR2
+// SI_IF_NZ %VCC
+//   %VGPR0 = V_ADD_F32 %VGPR0, %VGPR0
+// ELSE
+//   %VGPR0 = V_SUB_F32 %VGPR0, %VGPR0
+// ENDIF
+//
+// becomes:
+//
+// %SGPR0 = S_MOV_B64 %EXEC          // Save the current exec mask
+// %EXEC = S_AND_B64 %VCC, %EXEC     // Update the exec mask
+// %SGPR0 = S_XOR_B64 %SGPR0, %EXEC  // Clear live bits from saved exec mask
+// S_CBRANCH_EXECZ label0            // This instruction is an
+//                                   // optimization which allows us to
+//                                   // branch if all the bits of
+//                                   // EXEC are zero.
+// %VGPR0 = V_ADD_F32 %VGPR0, %VGPR0 // Do the IF block of the branch
+//
+// label0:
+// %SGPR2 = S_MOV_B64 %EXEC           // Save the current exec mask
+// %EXEC = S_MOV_B64 %SGPR0           // Restore the exec mask for the Then block
+// %SGPR0 = S_MOV_B64 %SGPR2          // Save the exec mask from the If block
+// S_BRANCH_EXECZ label1              // Use our branch optimization
+//                                    // instruction again.
+// %VGPR0 = V_SUB_F32 %VGPR0, %VGPR   // Do the THEN block
+// label1:
+// %EXEC = S_OR_B64 %EXEC, %SGPR0     // Re-enable saved exec mask bits
+//===----------------------------------------------------------------------===//
+
+#include "AMDGPU.h"
+#include "SIInstrInfo.h"
+#include "SIMachineFunctionInfo.h"
+#include "llvm/CodeGen/MachineFunction.h"
+#include "llvm/CodeGen/MachineFunctionPass.h"
+#include "llvm/CodeGen/MachineInstrBuilder.h"
+#include "llvm/CodeGen/MachineRegisterInfo.h"
+
+using namespace llvm;
+
+namespace {
+
+class SILowerControlFlowPass : public MachineFunctionPass {
+
+private:
+  static char ID;
+  const TargetInstrInfo *TII;
+  std::vector<unsigned> PredicateStack;
+  std::vector<unsigned> UnusedRegisters;
+
+  void pushExecMask(MachineBasicBlock &MBB, MachineBasicBlock::iterator I);
+  void popExecMask(MachineBasicBlock &MBB, MachineBasicBlock::iterator I);
+
+public:
+  SILowerControlFlowPass(TargetMachine &tm) :
+    MachineFunctionPass(ID), TII(tm.getInstrInfo()) { }
+
+  virtual bool runOnMachineFunction(MachineFunction &MF);
+
+  const char *getPassName() const {
+    return "SI Lower control flow instructions";
+  }
+
+};
+
+} // End anonymous namespace
+
+char SILowerControlFlowPass::ID = 0;
+
+FunctionPass *llvm::createSILowerControlFlowPass(TargetMachine &tm) {
+  return new SILowerControlFlowPass(tm);
+}
+
+bool SILowerControlFlowPass::runOnMachineFunction(MachineFunction &MF) {
+
+  // Find all the unused registers that can be used for the predicate stack.
+  for (TargetRegisterClass::iterator I = AMDGPU::SReg_64RegClass.begin(),
+                                     S = AMDGPU::SReg_64RegClass.end();
+                                     I != S; ++I) {
+    unsigned Reg = *I;
+    if (!MF.getRegInfo().isPhysRegUsed(Reg)) {
+      UnusedRegisters.insert(UnusedRegisters.begin(), Reg);
+    }
+  }
+
+  for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
+                                                  BB != BB_E; ++BB) {
+    MachineBasicBlock &MBB = *BB;
+    for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I);
+                               I != MBB.end(); I = Next) {
+      Next = llvm::next(I);
+      MachineInstr &MI = *I;
+      switch (MI.getOpcode()) {
+        default: break;
+        case AMDGPU::SI_IF_NZ:
+          pushExecMask(MBB, I);
+          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_AND_B64),
+                  AMDGPU::EXEC)
+                  .addOperand(MI.getOperand(0)) // VCC
+                  .addReg(AMDGPU::EXEC);
+          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_XOR_B64),
+                  PredicateStack.back())
+                  .addReg(PredicateStack.back())
+                  .addReg(AMDGPU::EXEC);
+          MI.eraseFromParent();
+          break;
+        case AMDGPU::ELSE:
+          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
+                  UnusedRegisters.back())
+                  .addReg(AMDGPU::EXEC);
+          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
+                  AMDGPU::EXEC)
+                  .addReg(PredicateStack.back());
+          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
+                  PredicateStack.back())
+                  .addReg(UnusedRegisters.back());
+          MI.eraseFromParent();
+          break;
+        case AMDGPU::ENDIF:
+          popExecMask(MBB, I);
+	  if (MF.getInfo<SIMachineFunctionInfo>()->ShaderType == ShaderType::PIXEL &&
+	      PredicateStack.empty()) {
+            // If the exec mask is non-zero, skip the next two instructions
+            BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_CBRANCH_EXECNZ))
+                    .addImm(3)
+                    .addReg(AMDGPU::EXEC);
+
+            // Exec mask is zero: Export to NULL target...
+            BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::EXP))
+                    .addImm(0)
+                    .addImm(0x09) // V_008DFC_SQ_EXP_NULL
+                    .addImm(0)
+                    .addImm(1)
+                    .addImm(1)
+                    .addReg(AMDGPU::SREG_LIT_0)
+                    .addReg(AMDGPU::SREG_LIT_0)
+                    .addReg(AMDGPU::SREG_LIT_0)
+                    .addReg(AMDGPU::SREG_LIT_0);
+
+            // ... and terminate wavefront
+            BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_ENDPGM));
+	  }
+          MI.eraseFromParent();
+          break;
+      }
+    }
+  }
+  return false;
+}
+
+void SILowerControlFlowPass::pushExecMask(MachineBasicBlock &MBB,
+                                          MachineBasicBlock::iterator I) {
+
+  assert(!UnusedRegisters.empty() && "Ran out of registers for predicate stack");
+  unsigned StackReg = UnusedRegisters.back();
+  UnusedRegisters.pop_back();
+  PredicateStack.push_back(StackReg);
+  BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
+          StackReg)
+          .addReg(AMDGPU::EXEC);
+}
+
+void SILowerControlFlowPass::popExecMask(MachineBasicBlock &MBB,
+                                        MachineBasicBlock::iterator I) {
+  unsigned StackReg = PredicateStack.back();
+  PredicateStack.pop_back();
+  UnusedRegisters.push_back(StackReg);
+  BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_OR_B64),
+          AMDGPU::EXEC)
+          .addReg(AMDGPU::EXEC)
+          .addReg(StackReg);
+}
diff --git a/lib/Target/AMDGPU/SILowerFlowControl.cpp b/lib/Target/AMDGPU/SILowerFlowControl.cpp
deleted file mode 100644
index 0d90c13..0000000
--- a/lib/Target/AMDGPU/SILowerFlowControl.cpp
+++ /dev/null
@@ -1,193 +0,0 @@
-//===-- SILowerFlowControl.cpp - Use predicates for flow control ----------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This pass lowers the pseudo flow control instructions (SI_IF_NZ, ELSE, ENDIF)
-// to predicated instructions.
-//
-// All flow control (except loops) is handled using predicated instructions and
-// a predicate stack.  Each Scalar ALU controls the operations of 64 Vector
-// ALUs.  The Scalar ALU can update the predicate for any of the Vector ALUs
-// by writting to the 64-bit EXEC register (each bit corresponds to a
-// single vector ALU).  Typically, for predicates, a vector ALU will write
-// to its bit of the VCC register (like EXEC VCC is 64-bits, one for each
-// Vector ALU) and then the ScalarALU will AND the VCC register with the
-// EXEC to update the predicates.
-//
-// For example:
-// %VCC = V_CMP_GT_F32 %VGPR1, %VGPR2
-// SI_IF_NZ %VCC
-//   %VGPR0 = V_ADD_F32 %VGPR0, %VGPR0
-// ELSE
-//   %VGPR0 = V_SUB_F32 %VGPR0, %VGPR0
-// ENDIF
-//
-// becomes:
-//
-// %SGPR0 = S_MOV_B64 %EXEC          // Save the current exec mask
-// %EXEC = S_AND_B64 %VCC, %EXEC     // Update the exec mask
-// %SGPR0 = S_XOR_B64 %SGPR0, %EXEC  // Clear live bits from saved exec mask
-// S_CBRANCH_EXECZ label0            // This instruction is an
-//                                   // optimization which allows us to
-//                                   // branch if all the bits of
-//                                   // EXEC are zero.
-// %VGPR0 = V_ADD_F32 %VGPR0, %VGPR0 // Do the IF block of the branch
-//
-// label0:
-// %SGPR2 = S_MOV_B64 %EXEC           // Save the current exec mask
-// %EXEC = S_MOV_B64 %SGPR0           // Restore the exec mask for the Then block
-// %SGPR0 = S_MOV_B64 %SGPR2          // Save the exec mask from the If block
-// S_BRANCH_EXECZ label1              // Use our branch optimization
-//                                    // instruction again.
-// %VGPR0 = V_SUB_F32 %VGPR0, %VGPR   // Do the THEN block
-// label1:
-// %EXEC = S_OR_B64 %EXEC, %SGPR0     // Re-enable saved exec mask bits
-//===----------------------------------------------------------------------===//
-
-#include "AMDGPU.h"
-#include "SIInstrInfo.h"
-#include "SIMachineFunctionInfo.h"
-#include "llvm/CodeGen/MachineFunction.h"
-#include "llvm/CodeGen/MachineFunctionPass.h"
-#include "llvm/CodeGen/MachineInstrBuilder.h"
-#include "llvm/CodeGen/MachineRegisterInfo.h"
-
-using namespace llvm;
-
-namespace {
-
-class SILowerFlowControlPass : public MachineFunctionPass {
-
-private:
-  static char ID;
-  const TargetInstrInfo *TII;
-  std::vector<unsigned> PredicateStack;
-  std::vector<unsigned> UnusedRegisters;
-
-  void pushExecMask(MachineBasicBlock &MBB, MachineBasicBlock::iterator I);
-  void popExecMask(MachineBasicBlock &MBB, MachineBasicBlock::iterator I);
-
-public:
-  SILowerFlowControlPass(TargetMachine &tm) :
-    MachineFunctionPass(ID), TII(tm.getInstrInfo()) { }
-
-  virtual bool runOnMachineFunction(MachineFunction &MF);
-
-  const char *getPassName() const {
-    return "SI Lower flow control instructions";
-  }
-
-};
-
-} // End anonymous namespace
-
-char SILowerFlowControlPass::ID = 0;
-
-FunctionPass *llvm::createSILowerFlowControlPass(TargetMachine &tm) {
-  return new SILowerFlowControlPass(tm);
-}
-
-bool SILowerFlowControlPass::runOnMachineFunction(MachineFunction &MF) {
-
-  // Find all the unused registers that can be used for the predicate stack.
-  for (TargetRegisterClass::iterator I = AMDGPU::SReg_64RegClass.begin(),
-                                     S = AMDGPU::SReg_64RegClass.end();
-                                     I != S; ++I) {
-    unsigned Reg = *I;
-    if (!MF.getRegInfo().isPhysRegUsed(Reg)) {
-      UnusedRegisters.insert(UnusedRegisters.begin(), Reg);
-    }
-  }
-
-  for (MachineFunction::iterator BB = MF.begin(), BB_E = MF.end();
-                                                  BB != BB_E; ++BB) {
-    MachineBasicBlock &MBB = *BB;
-    for (MachineBasicBlock::iterator I = MBB.begin(), Next = llvm::next(I);
-                               I != MBB.end(); I = Next) {
-      Next = llvm::next(I);
-      MachineInstr &MI = *I;
-      switch (MI.getOpcode()) {
-        default: break;
-        case AMDGPU::SI_IF_NZ:
-          pushExecMask(MBB, I);
-          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_AND_B64),
-                  AMDGPU::EXEC)
-                  .addOperand(MI.getOperand(0)) // VCC
-                  .addReg(AMDGPU::EXEC);
-          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_XOR_B64),
-                  PredicateStack.back())
-                  .addReg(PredicateStack.back())
-                  .addReg(AMDGPU::EXEC);
-          MI.eraseFromParent();
-          break;
-        case AMDGPU::ELSE:
-          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
-                  UnusedRegisters.back())
-                  .addReg(AMDGPU::EXEC);
-          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
-                  AMDGPU::EXEC)
-                  .addReg(PredicateStack.back());
-          BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
-                  PredicateStack.back())
-                  .addReg(UnusedRegisters.back());
-          MI.eraseFromParent();
-          break;
-        case AMDGPU::ENDIF:
-          popExecMask(MBB, I);
-	  if (MF.getInfo<SIMachineFunctionInfo>()->ShaderType == ShaderType::PIXEL &&
-	      PredicateStack.empty()) {
-            // If the exec mask is non-zero, skip the next two instructions
-            BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_CBRANCH_EXECNZ))
-                    .addImm(3)
-                    .addReg(AMDGPU::EXEC);
-
-            // Exec mask is zero: Export to NULL target...
-            BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::EXP))
-                    .addImm(0)
-                    .addImm(0x09) // V_008DFC_SQ_EXP_NULL
-                    .addImm(0)
-                    .addImm(1)
-                    .addImm(1)
-                    .addReg(AMDGPU::SREG_LIT_0)
-                    .addReg(AMDGPU::SREG_LIT_0)
-                    .addReg(AMDGPU::SREG_LIT_0)
-                    .addReg(AMDGPU::SREG_LIT_0);
-
-            // ... and terminate wavefront
-            BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_ENDPGM));
-	  }
-          MI.eraseFromParent();
-          break;
-      }
-    }
-  }
-  return false;
-}
-
-void SILowerFlowControlPass::pushExecMask(MachineBasicBlock &MBB,
-                                          MachineBasicBlock::iterator I) {
-
-  assert(!UnusedRegisters.empty() && "Ran out of registers for predicate stack");
-  unsigned StackReg = UnusedRegisters.back();
-  UnusedRegisters.pop_back();
-  PredicateStack.push_back(StackReg);
-  BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_MOV_B64),
-          StackReg)
-          .addReg(AMDGPU::EXEC);
-}
-
-void SILowerFlowControlPass::popExecMask(MachineBasicBlock &MBB,
-                                        MachineBasicBlock::iterator I) {
-  unsigned StackReg = PredicateStack.back();
-  PredicateStack.pop_back();
-  UnusedRegisters.push_back(StackReg);
-  BuildMI(MBB, I, MBB.findDebugLoc(I), TII->get(AMDGPU::S_OR_B64),
-          AMDGPU::EXEC)
-          .addReg(AMDGPU::EXEC)
-          .addReg(StackReg);
-}
-- 
1.7.10.4



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