AMDGPU/GlobalISel: Define InstrMappings for G_ICMP

Patch by Tom Stellard

llvm-svn: 326472

5 files changed, 168 insertions, 15 deletions

diff --git a/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def b/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def
index bf7deb500d1..336c5e726ab 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def
+++ b/llvm/lib/Target/AMDGPU/AMDGPUGenRegisterBankInfo.def
@@ -19,7 +19,9 @@ enum PartialMappingIdx {
   PM_SGPR32 = 0,
   PM_SGPR64 = 1,
   PM_VGPR32 = 2,
-  PM_VGPR64 = 3
+  PM_VGPR64 = 3,
+  PM_SGPR1  = 4,
+  PM_VGPR1  = 5,
 };
 
 const RegisterBankInfo::PartialMapping PartMappings[] {
@@ -27,7 +29,9 @@ const RegisterBankInfo::PartialMapping PartMappings[] {
   {0, 32, SGPRRegBank},
   {0, 64, SGPRRegBank},
   {0, 32, VGPRRegBank},
-  {0, 64, VGPRRegBank}
+  {0, 64, VGPRRegBank},
+  {0, 1,  SCCRegBank},
+  {0, 1,  SGPRRegBank}
 };
 
 const RegisterBankInfo::ValueMapping ValMappings[] {
@@ -38,7 +42,9 @@ const RegisterBankInfo::ValueMapping ValMappings[] {
   // VGPR 32-bit
   {&PartMappings[2], 1},
   // VGPR 64-bit
-  {&PartMappings[3], 1}
+  {&PartMappings[3], 1},
+  {&PartMappings[4], 1},
+  {&PartMappings[5], 1}
 };
 
 enum ValueMappingIdx {
@@ -48,9 +54,14 @@ enum ValueMappingIdx {
 
 const RegisterBankInfo::ValueMapping *getValueMapping(unsigned BankID,
                                                       unsigned Size) {
-  assert(Size % 32 == 0);
-  unsigned Idx = BankID == AMDGPU::SGPRRegBankID ? SGPRStartIdx : VGPRStartIdx;
-  Idx += (Size / 32) - 1;
+  unsigned Idx;
+  if (Size == 1) {
+    Idx = BankID == AMDGPU::SCCRegBankID ? PM_SGPR1 : PM_VGPR1;
+  } else {
+    assert(Size % 32 == 0);
+    Idx = BankID == AMDGPU::SGPRRegBankID ? SGPRStartIdx : VGPRStartIdx;
+    Idx += (Size / 32) - 1;
+  }
   return &ValMappings[Idx];
 }
 
diff --git a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
index 8d94898415b..a2647addc4e 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
+++ b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.cpp
@@ -56,6 +56,13 @@ unsigned AMDGPURegisterBankInfo::copyCost(const RegisterBank &Dst,
   if (Dst.getID() == AMDGPU::SGPRRegBankID &&
       Src.getID() == AMDGPU::VGPRRegBankID)
     return std::numeric_limits<unsigned>::max();
+
+  // SGPRRegBank with size 1 is actually vcc or another 64-bit sgpr written by
+  // the valu.
+  if (Size == 1 && Dst.getID() == AMDGPU::SCCRegBankID &&
+      Src.getID() == AMDGPU::SGPRRegBankID)
+    return std::numeric_limits<unsigned>::max();
+
   return RegisterBankInfo::copyCost(Dst, Src, Size);
 }
 
@@ -75,11 +82,11 @@ AMDGPURegisterBankInfo::getInstrAlternativeMappings(
   const MachineFunction &MF = *MI.getParent()->getParent();
   const MachineRegisterInfo &MRI = MF.getRegInfo();
 
-  unsigned Size = getSizeInBits(MI.getOperand(0).getReg(), MRI, *TRI);
 
   InstructionMappings AltMappings;
   switch (MI.getOpcode()) {
   case TargetOpcode::G_LOAD: {
+    unsigned Size = getSizeInBits(MI.getOperand(0).getReg(), MRI, *TRI);
     // FIXME: Should we be hard coding the size for these mappings?
     const InstructionMapping &SSMapping = getInstructionMapping(
         1, 1, getOperandsMapping(
@@ -107,6 +114,42 @@ AMDGPURegisterBankInfo::getInstrAlternativeMappings(
     return AltMappings;
 
   }
+  case TargetOpcode::G_ICMP: {
+    unsigned Size = getSizeInBits(MI.getOperand(2).getReg(), MRI, *TRI);
+    const InstructionMapping &SSMapping = getInstructionMapping(1, 1,
+      getOperandsMapping({AMDGPU::getValueMapping(AMDGPU::SCCRegBankID, 1),
+                          nullptr, // Predicate operand.
+                          AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, Size),
+                          AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, Size)}),
+      4); // Num Operands
+    AltMappings.push_back(&SSMapping);
+
+    const InstructionMapping &SVMapping = getInstructionMapping(2, 1,
+      getOperandsMapping({AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, 1),
+                          nullptr, // Predicate operand.
+                          AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, Size),
+                          AMDGPU::getValueMapping(AMDGPU::VGPRRegBankID, Size)}),
+      4); // Num Operands
+    AltMappings.push_back(&SVMapping);
+
+    const InstructionMapping &VSMapping = getInstructionMapping(3, 1,
+      getOperandsMapping({AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, 1),
+                          nullptr, // Predicate operand.
+                          AMDGPU::getValueMapping(AMDGPU::VGPRRegBankID, Size),
+                          AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, Size)}),
+      4); // Num Operands
+    AltMappings.push_back(&VSMapping);
+
+    const InstructionMapping &VVMapping = getInstructionMapping(4, 1,
+      getOperandsMapping({AMDGPU::getValueMapping(AMDGPU::SGPRRegBankID, 1),
+                          nullptr, // Predicate operand.
+                          AMDGPU::getValueMapping(AMDGPU::VGPRRegBankID, Size),
+                          AMDGPU::getValueMapping(AMDGPU::VGPRRegBankID, Size)}),
+      4); // Num Operands
+    AltMappings.push_back(&VVMapping);
+
+    return AltMappings;
+  }
   default:
     break;
   }
@@ -158,6 +201,22 @@ AMDGPURegisterBankInfo::getInstrMappingForLoad(const MachineInstr &MI) const {
   // handle that during instruction selection?
 }
 
+unsigned
+AMDGPURegisterBankInfo::getRegBankID(unsigned Reg,
+                                     const MachineRegisterInfo &MRI,
+                                     const TargetRegisterInfo &TRI,
+                                     unsigned Default) const {
+
+  const RegisterBank *Bank = getRegBank(Reg, MRI, TRI);
+  return Bank ? Bank->getID() : Default;
+}
+
+///
+/// This function must return a legal mapping, because
+/// AMDGPURegisterBankInfo::getInstrAlternativeMappings() is not called
+/// in RegBankSelect::Mode::Fast.  Any mapping that would cause a
+/// VGPR to SGPR generated is illegal.
+///
 const RegisterBankInfo::InstructionMapping &
 AMDGPURegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
   const RegisterBankInfo::InstructionMapping &Mapping = getInstrMappingImpl(MI);
@@ -213,6 +272,20 @@ AMDGPURegisterBankInfo::getInstrMapping(const MachineInstr &MI) const {
     break;
   }
 
+  case AMDGPU::G_ICMP: {
+    unsigned Size = MRI.getType(MI.getOperand(2).getReg()).getSizeInBits();
+    unsigned Op2Bank = getRegBankID(MI.getOperand(2).getReg(), MRI, *TRI);
+    unsigned Op3Bank = getRegBankID(MI.getOperand(3).getReg(), MRI, *TRI);
+    unsigned Op0Bank = Op2Bank == AMDGPU::SGPRRegBankID &&
+                       Op3Bank == AMDGPU::SGPRRegBankID ?
+                       AMDGPU::SCCRegBankID : AMDGPU::VGPRRegBankID;
+    OpdsMapping[0] = AMDGPU::getValueMapping(Op0Bank, 1);
+    OpdsMapping[1] = nullptr; // Predicate Operand.
+    OpdsMapping[2] = AMDGPU::getValueMapping(Op2Bank, Size);
+    OpdsMapping[3] = AMDGPU::getValueMapping(Op3Bank, Size);
+    break;
+  }
+
   case AMDGPU::G_LOAD:
     return getInstrMappingForLoad(MI);
   }
diff --git a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.h b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.h
index 201fdc1974c..31589236b94 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.h
+++ b/llvm/lib/Target/AMDGPU/AMDGPURegisterBankInfo.h
@@ -16,19 +16,15 @@
 
 #include "llvm/CodeGen/GlobalISel/RegisterBankInfo.h"
 
+#define GET_REGBANK_DECLARATIONS
+#include "AMDGPUGenRegisterBank.inc"
+#undef GET_REGBANK_DECLARATIONS
+
 namespace llvm {
 
 class SIRegisterInfo;
 class TargetRegisterInfo;
 
-namespace AMDGPU {
-enum {
-  SGPRRegBankID = 0,
-  VGPRRegBankID = 1,
-  NumRegisterBanks
-};
-} // End AMDGPU namespace.
-
 /// This class provides the information for the target register banks.
 class AMDGPUGenRegisterBankInfo : public RegisterBankInfo {
 
@@ -46,6 +42,10 @@ class AMDGPURegisterBankInfo : public AMDGPUGenRegisterBankInfo {
   const RegisterBankInfo::InstructionMapping &
   getInstrMappingForLoad(const MachineInstr &MI) const;
 
+  unsigned getRegBankID(unsigned Reg, const MachineRegisterInfo &MRI,
+                        const TargetRegisterInfo &TRI,
+                        unsigned Default = AMDGPU::VGPRRegBankID) const;
+
 public:
   AMDGPURegisterBankInfo(const TargetRegisterInfo &TRI);
 
diff --git a/llvm/lib/Target/AMDGPU/AMDGPURegisterBanks.td b/llvm/lib/Target/AMDGPU/AMDGPURegisterBanks.td
index f4428e56035..7f7f75f6564 100644
--- a/llvm/lib/Target/AMDGPU/AMDGPURegisterBanks.td
+++ b/llvm/lib/Target/AMDGPU/AMDGPURegisterBanks.td
@@ -14,3 +14,5 @@ def SGPRRegBank : RegisterBank<"SGPR",
 def VGPRRegBank : RegisterBank<"VGPR",
   [VGPR_32, VReg_64, VReg_96, VReg_128, VReg_256, VReg_512]
 >;
+
+def SCCRegBank : RegisterBank <"SCC", [SCC_CLASS ]>;
diff --git a/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-icmp.mir b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-icmp.mir
new file mode 100644
index 00000000000..114a6d0b251
--- /dev/null
+++ b/llvm/test/CodeGen/AMDGPU/GlobalISel/regbankselect-icmp.mir
@@ -0,0 +1,67 @@
+# NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
+# RUN: llc -march=amdgcn -mcpu=fiji -run-pass=regbankselect -global-isel %s -verify-machineinstrs -o - -regbankselect-fast | FileCheck %s
+# RUN: llc -march=amdgcn -mcpu=fiji -run-pass=regbankselect -global-isel %s -verify-machineinstrs -o - -regbankselect-greedy | FileCheck %s
+
+---
+name: icmp_ss
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $sgpr0, $sgpr1
+    ; CHECK-LABEL: name: icmp_ss
+    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s32) = COPY $sgpr0
+    ; CHECK: [[COPY1:%[0-9]+]]:sgpr(s32) = COPY $sgpr1
+    ; CHECK: [[ICMP:%[0-9]+]]:scc(s1) = G_ICMP intpred(ne), [[COPY]](s32), [[COPY1]]
+    %0:_(s32) = COPY $sgpr0
+    %1:_(s32) = COPY $sgpr1
+    %2:_(s1) = G_ICMP intpred(ne), %0, %1
+...
+
+---
+name: icmp_sv
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $sgpr0, $vgpr0
+    ; CHECK-LABEL: name: icmp_sv
+    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s32) = COPY $sgpr0
+    ; CHECK: [[COPY1:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
+    ; CHECK: [[ICMP:%[0-9]+]]:sgpr(s1) = G_ICMP intpred(ne), [[COPY]](s32), [[COPY1]]
+    %0:_(s32) = COPY $sgpr0
+    %1:_(s32) = COPY $vgpr0
+    %2:_(s1) = G_ICMP intpred(ne), %0, %1
+...
+
+---
+name: icmp_vs
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $sgpr0, $vgpr0
+    ; CHECK-LABEL: name: icmp_vs
+    ; CHECK: [[COPY:%[0-9]+]]:sgpr(s32) = COPY $sgpr0
+    ; CHECK: [[COPY1:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
+    ; CHECK: [[ICMP:%[0-9]+]]:sgpr(s1) = G_ICMP intpred(ne), [[COPY1]](s32), [[COPY]]
+    %0:_(s32) = COPY $sgpr0
+    %1:_(s32) = COPY $vgpr0
+    %2:_(s1) = G_ICMP intpred(ne), %1, %0
+...
+
+---
+name: icmp_vv
+legalized: true
+
+body: |
+  bb.0:
+    liveins: $vgpr0, $vgpr1
+    ; CHECK-LABEL: name: icmp_vv
+    ; CHECK: [[COPY:%[0-9]+]]:vgpr(s32) = COPY $vgpr0
+    ; CHECK: [[COPY1:%[0-9]+]]:vgpr(s32) = COPY $vgpr1
+    ; CHECK: [[ICMP:%[0-9]+]]:sgpr(s1) = G_ICMP intpred(ne), [[COPY]](s32), [[COPY1]]
+    %0:_(s32) = COPY $vgpr0
+    %1:_(s32) = COPY $vgpr1
+    %2:_(s1) = G_ICMP intpred(ne), %0, %1
+...