implement integer compare in mips fast-isel

Summary: implement SelectCmp (integer compare ) in mips fast-isel

Test Plan:
icmpa.ll
also ran 4 test-suite flavors mips32 r1/r2 O0/O2

Reviewers: dsanders

Reviewed By: dsanders

Subscribers: llvm-commits, rfuhler, mcrosier

Differential Revision: http://reviews.llvm.org/D5566

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219518 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/Mips/MipsFastISel.cpp b/lib/Target/Mips/MipsFastISel.cpp
index 63299f9b9888d852175544edd607059f79fddbf6..a2817f7d6cbf1c21dfc4e9fa37cef6797aaf22e5 100644 (file)
--- a/lib/Target/Mips/MipsFastISel.cpp
+++ b/lib/Target/Mips/MipsFastISel.cpp
@@ -85,10 +85,13 @@ private:
   bool SelectFPExt(const Instruction *I);
   bool SelectFPTrunc(const Instruction *I);
   bool SelectFPToI(const Instruction *I, bool IsSigned);
+  bool SelectCmp(const Instruction *I);
 
   bool isTypeLegal(Type *Ty, MVT &VT);
   bool isLoadTypeLegal(Type *Ty, MVT &VT);
 
+  unsigned getRegEnsuringSimpleIntegerWidening(const Value *, bool IsUnsigned);
+
   unsigned MaterializeFP(const ConstantFP *CFP, MVT VT);
   unsigned MaterializeGV(const GlobalValue *GV, MVT VT);
   unsigned MaterializeInt(const Constant *C, MVT VT);
@@ -171,6 +174,21 @@ bool MipsFastISel::ComputeAddress(const Value *Obj, Address &Addr) {
   return Addr.Base.Reg != 0;
 }
 
+unsigned MipsFastISel::getRegEnsuringSimpleIntegerWidening(const Value *V,
+                                                           bool IsUnsigned) {
+  unsigned VReg = getRegForValue(V);
+  if (VReg == 0)
+    return 0;
+  MVT VMVT = TLI.getValueType(V->getType(), true).getSimpleVT();
+  if ((VMVT == MVT::i8) || (VMVT == MVT::i16)) {
+    unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
+    if (!EmitIntExt(VMVT, VReg, MVT::i32, TempReg, IsUnsigned))
+      return 0;
+    VReg = TempReg;
+  }
+  return VReg;
+}
+
 bool MipsFastISel::EmitLoad(MVT VT, unsigned &ResultReg, Address &Addr,
                             unsigned Alignment) {
   //
@@ -543,6 +561,84 @@ bool MipsFastISel::SelectFPToI(const Instruction *I, bool IsSigned) {
   return true;
 }
 
+//
+// Because of how SelectCmp is called with fast-isel, you can
+// end up with redundant "andi" instructions after the sequences emitted below.
+// We should try and solve this issue in the future.
+//
+bool MipsFastISel::SelectCmp(const Instruction *I) {
+  const CmpInst *CI = cast<CmpInst>(I);
+  bool IsUnsigned = CI->isUnsigned();
+  const Value *Left = I->getOperand(0), *Right = I->getOperand(1);
+
+  unsigned LeftReg = getRegEnsuringSimpleIntegerWidening(Left, IsUnsigned);
+  if (LeftReg == 0)
+    return false;
+  unsigned RightReg = getRegEnsuringSimpleIntegerWidening(Right, IsUnsigned);
+  if (RightReg == 0)
+    return false;
+  unsigned ResultReg = createResultReg(&Mips::GPR32RegClass);
+
+  switch (CI->getPredicate()) {
+  default:
+    return false;
+  case CmpInst::ICMP_EQ: {
+    unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
+    EmitInst(Mips::XOR, TempReg).addReg(LeftReg).addReg(RightReg);
+    EmitInst(Mips::SLTiu, ResultReg).addReg(TempReg).addImm(1);
+    break;
+  }
+  case CmpInst::ICMP_NE: {
+    unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
+    EmitInst(Mips::XOR, TempReg).addReg(LeftReg).addReg(RightReg);
+    EmitInst(Mips::SLTu, ResultReg).addReg(Mips::ZERO).addReg(TempReg);
+    break;
+  }
+  case CmpInst::ICMP_UGT: {
+    EmitInst(Mips::SLTu, ResultReg).addReg(RightReg).addReg(LeftReg);
+    break;
+  }
+  case CmpInst::ICMP_ULT: {
+    EmitInst(Mips::SLTu, ResultReg).addReg(LeftReg).addReg(RightReg);
+    break;
+  }
+  case CmpInst::ICMP_UGE: {
+    unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
+    EmitInst(Mips::SLTu, TempReg).addReg(LeftReg).addReg(RightReg);
+    EmitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
+    break;
+  }
+  case CmpInst::ICMP_ULE: {
+    unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
+    EmitInst(Mips::SLTu, TempReg).addReg(RightReg).addReg(LeftReg);
+    EmitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
+    break;
+  }
+  case CmpInst::ICMP_SGT: {
+    EmitInst(Mips::SLT, ResultReg).addReg(RightReg).addReg(LeftReg);
+    break;
+  }
+  case CmpInst::ICMP_SLT: {
+    EmitInst(Mips::SLT, ResultReg).addReg(LeftReg).addReg(RightReg);
+    break;
+  }
+  case CmpInst::ICMP_SGE: {
+    unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
+    EmitInst(Mips::SLT, TempReg).addReg(LeftReg).addReg(RightReg);
+    EmitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
+    break;
+  }
+  case CmpInst::ICMP_SLE: {
+    unsigned TempReg = createResultReg(&Mips::GPR32RegClass);
+    EmitInst(Mips::SLT, TempReg).addReg(RightReg).addReg(LeftReg);
+    EmitInst(Mips::XORi, ResultReg).addReg(TempReg).addImm(1);
+    break;
+  }
+  }
+  updateValueMap(I, ResultReg);
+  return true;
+}
+
 bool MipsFastISel::fastSelectInstruction(const Instruction *I) {
   if (!TargetSupported)
     return false;
@@ -568,6 +664,9 @@ bool MipsFastISel::fastSelectInstruction(const Instruction *I) {
     return SelectFPToI(I, /*isSigned*/ true);
   case Instruction::FPToUI:
     return SelectFPToI(I, /*isSigned*/ false);
+  case Instruction::ICmp:
+  case Instruction::FCmp:
+    return SelectCmp(I);
   }
   return false;
 }

diff --git a/test/CodeGen/Mips/Fast-ISel/icmpa.ll b/test/CodeGen/Mips/Fast-ISel/icmpa.ll
new file mode 100644 (file)
index 0000000..c4db6ec
--- /dev/null
+++ b/test/CodeGen/Mips/Fast-ISel/icmpa.ll
@@ -0,0 +1,203 @@
+; RUN: llc -march=mipsel -relocation-model=pic -O0 -mips-fast-isel -fast-isel-abort -mcpu=mips32r2 \
+; RUN:     < %s | FileCheck %s
+; RUN: llc -march=mipsel -relocation-model=pic -O0 -mips-fast-isel -fast-isel-abort -mcpu=mips32 \
+; RUN:     < %s | FileCheck %s
+
+@c = global i32 4, align 4
+@d = global i32 9, align 4
+@uc = global i32 4, align 4
+@ud = global i32 9, align 4
+@b1 = common global i32 0, align 4
+
+; Function Attrs: nounwind
+define void @eq()  {
+entry:
+; CHECK-LABEL:  .ent  eq
+
+  %0 = load i32* @c, align 4
+  %1 = load i32* @d, align 4
+  %cmp = icmp eq i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_D_GOT:[0-9+]]], %got(d)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_C_GOT:[0-9+]]], %got(c)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_D:[0-9]+]], 0($[[REG_D_GOT]])
+; CHECK-DAG:  lw       $[[REG_C:[0-9]+]], 0($[[REG_C_GOT]])
+; CHECK:  xor  $[[REG1:[0-9]+]], $[[REG_C]], $[[REG_D]]
+; CHECK:  sltiu  $[[REG2:[0-9]+]], $[[REG1]], 1
+; FIXME: This instruction is redundant. The sltiu can only produce 0 and 1.
+; CHECK:  andi  ${{[0-9]+}}, $[[REG2]], 1
+
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @ne()  {
+entry:
+; CHECK-LABEL:  .ent  ne
+  %0 = load i32* @c, align 4
+  %1 = load i32* @d, align 4
+  %cmp = icmp ne i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_D_GOT:[0-9+]]], %got(d)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_C_GOT:[0-9+]]], %got(c)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_D:[0-9]+]], 0($[[REG_D_GOT]])
+; CHECK-DAG:  lw       $[[REG_C:[0-9]+]], 0($[[REG_C_GOT]])
+; CHECK:  xor  $[[REG1:[0-9]+]], $[[REG_C]], $[[REG_D]]
+; CHECK:  sltu  $[[REG2:[0-9]+]], $zero, $[[REG1]]
+; CHECK:  andi  ${{[0-9]+}}, $[[REG2]], 1
+
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @ugt()  {
+entry:
+; CHECK-LABEL:  .ent  ugt
+  %0 = load i32* @uc, align 4
+  %1 = load i32* @ud, align 4
+  %cmp = icmp ugt i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_UD_GOT:[0-9+]]], %got(ud)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UC_GOT:[0-9+]]], %got(uc)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UD:[0-9]+]], 0($[[REG_UD_GOT]])
+; CHECK-DAG:  lw       $[[REG_UC:[0-9]+]], 0($[[REG_UC_GOT]])
+; CHECK:  sltu  $[[REG1:[0-9]+]], $[[REG_UD]], $[[REG_UC]]
+; CHECK:  andi  ${{[0-9]+}}, $[[REG1]], 1
+
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @ult()  {
+entry:
+; CHECK-LABEL:  .ent  ult
+  %0 = load i32* @uc, align 4
+  %1 = load i32* @ud, align 4
+  %cmp = icmp ult i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_UD_GOT:[0-9+]]], %got(ud)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UC_GOT:[0-9+]]], %got(uc)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UD:[0-9]+]], 0($[[REG_UD_GOT]])
+; CHECK-DAG:  lw       $[[REG_UC:[0-9]+]], 0($[[REG_UC_GOT]])
+; CHECK:  sltu  $[[REG1:[0-9]+]], $[[REG_UC]], $[[REG_UD]]
+; CHECK:  andi  ${{[0-9]+}}, $[[REG1]], 1
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @uge()  {
+entry:
+; CHECK-LABEL:  .ent  uge
+  %0 = load i32* @uc, align 4
+  %1 = load i32* @ud, align 4
+  %cmp = icmp uge i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_UD_GOT:[0-9+]]], %got(ud)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UC_GOT:[0-9+]]], %got(uc)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UD:[0-9]+]], 0($[[REG_UD_GOT]])
+; CHECK-DAG:  lw       $[[REG_UC:[0-9]+]], 0($[[REG_UC_GOT]])
+; CHECK:  sltu  $[[REG1:[0-9]+]], $[[REG_UC]], $[[REG_UD]]
+; CHECK:  xori  $[[REG2:[0-9]+]], $[[REG1]], 1
+; CHECK:  andi  ${{[0-9]+}}, $[[REG2]], 1
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @ule()  {
+entry:
+; CHECK-LABEL:  .ent  ule
+  %0 = load i32* @uc, align 4
+  %1 = load i32* @ud, align 4
+  %cmp = icmp ule i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_UD_GOT:[0-9+]]], %got(ud)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UC_GOT:[0-9+]]], %got(uc)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_UD:[0-9]+]], 0($[[REG_UD_GOT]])
+; CHECK-DAG:  lw       $[[REG_UC:[0-9]+]], 0($[[REG_UC_GOT]])
+; CHECK:  sltu  $[[REG1:[0-9]+]], $[[REG_UD]], $[[REG_UC]]
+; CHECK:  xori  $[[REG2:[0-9]+]], $[[REG1]], 1
+; CHECK:  andi  ${{[0-9]+}}, $[[REG2]], 1
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @sgt()  {
+entry:
+; CHECK-LABEL:  .ent sgt
+  %0 = load i32* @c, align 4
+  %1 = load i32* @d, align 4
+  %cmp = icmp sgt i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_D_GOT:[0-9+]]], %got(d)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_C_GOT:[0-9+]]], %got(c)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_D:[0-9]+]], 0($[[REG_D_GOT]])
+; CHECK-DAG:  lw       $[[REG_C:[0-9]+]], 0($[[REG_C_GOT]])
+; CHECK:  slt  $[[REG1:[0-9]+]], $[[REG_D]], $[[REG_C]]
+; CHECK:  andi  ${{[0-9]+}}, $[[REG1]], 1
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @slt()  {
+entry:
+; CHECK-LABEL:  .ent slt
+  %0 = load i32* @c, align 4
+  %1 = load i32* @d, align 4
+  %cmp = icmp slt i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_D_GOT:[0-9+]]], %got(d)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_C_GOT:[0-9+]]], %got(c)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_D:[0-9]+]], 0($[[REG_D_GOT]])
+; CHECK-DAG:  lw       $[[REG_C:[0-9]+]], 0($[[REG_C_GOT]])
+; CHECK:  slt  $[[REG1:[0-9]+]], $[[REG_C]], $[[REG_D]]
+; CHECK:  andi  ${{[0-9]+}}, $[[REG1]], 1
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @sge()  {
+entry:
+; CHECK-LABEL:  .ent sge
+  %0 = load i32* @c, align 4
+  %1 = load i32* @d, align 4
+  %cmp = icmp sge i32 %0, %1
+  %conv = zext i1 %cmp to i32
+  store i32 %conv, i32* @b1, align 4
+; CHECK-DAG:  lw       $[[REG_D_GOT:[0-9+]]], %got(d)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_C_GOT:[0-9+]]], %got(c)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_D:[0-9]+]], 0($[[REG_D_GOT]])
+; CHECK-DAG:  lw       $[[REG_C:[0-9]+]], 0($[[REG_C_GOT]])
+; CHECK:  slt  $[[REG1:[0-9]+]], $[[REG_C]], $[[REG_D]]
+; CHECK:  xori  $[[REG2:[0-9]+]], $[[REG1]], 1
+; CHECK:  andi  ${{[0-9]+}}, $[[REG2]], 1
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @sle()  {
+entry:
+; CHECK-LABEL:  .ent sle
+  %0 = load i32* @c, align 4
+  %1 = load i32* @d, align 4
+  %cmp = icmp sle i32 %0, %1
+  %conv = zext i1 %cmp to i32
+; CHECK-DAG:  lw       $[[REG_D_GOT:[0-9+]]], %got(d)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_C_GOT:[0-9+]]], %got(c)(${{[0-9]+}})
+; CHECK-DAG:  lw       $[[REG_D:[0-9]+]], 0($[[REG_D_GOT]])
+; CHECK-DAG:  lw       $[[REG_C:[0-9]+]], 0($[[REG_C_GOT]])
+; CHECK:        slt     $[[REG1:[0-9]+]], $[[REG_D]], $[[REG_C]]
+; CHECK:        xori    $[[REG2:[0-9]+]], $[[REG1]], 1
+; CHECK:        andi    ${{[0-9]+}}, $[[REG2]], 1
+  store i32 %conv, i32* @b1, align 4
+  ret void
+}
+
+