Finish materialize for ints

[rkotler]

Summary

We add code to materialize all integer literals.

[dsanders]

lib/Target/Mips/MipsFastISel.cpp

246–274

You could share more code between the paths using something like:

unsigned Hi = (Imm >> 16) & 0xffff;
unsigned Lo = Imm & 0xffff;

if (Hi && !isImm<16>(Imm)) {
  BuildMI(..., TII.get(Mips::LUi), ...)...
  Imm &= 0xffff;
}
if (Lo) {
  unsigned Opcode = isImm<16>(Imm) ? Mips::ADDiu : Mips::ORi)
  BuildMI(..., TII.get(Opcode), ...)...
}

test/CodeGen/Mips/Fast-ISel/simplestorei.ll

11–13

Inconsistent indentation. It happens in the other functions too.

[rkotler]

lib/Target/Mips/MipsFastISel.cpp

246–274

I see your point now. We can change it as you suggest. I just need to add some comments.

[rkotler]

lib/Target/Mips/MipsFastISel.cpp

246–274

Upon further reflection, I think that what I have now is very clear.

I don't think we are adding anything from reducing a few lines of code.
It will, IMO, just make it more difficult to understand.

Right now there are four case:
16 bit (signed and unsigned), 32 bit with lower have 0, 32 bit unrestricted

I would like to go back though and make some better BuildMI functions because we are repeating too many of the same parameters.

[rkotler]

• untabify test case

[dsanders]

LGTM with the indentation nits.

lib/Target/Mips/MipsFastISel.cpp

246–274

I disagree but it's very subjective and I don't have a strong argument in favour of either style. I suspect that you'll find the number of cases grows significantly when support for 64-bit immediates is added (particularly with MIPS64r6). We can refactor if/when that happens.

[dsanders]

The indentation nits are already fixed. LGTM.

lib/Target/Mips/MipsFastISel.cpp

private:
   bool SelectStore(const Instruction *I);
 
   bool isTypeLegal(Type *Ty, MVT &VT);
   bool isLoadTypeLegal(Type *Ty, MVT &VT);
 
   unsigned MaterializeFP(const ConstantFP *CFP, MVT VT);
   unsigned MaterializeGV(const GlobalValue *GV, MVT VT);
   unsigned MaterializeInt(const Constant *C, MVT VT);
+  unsigned Materialize32BitInt(int64_t Imm, const TargetRegisterClass *RC);
 };
 
 bool MipsFastISel::isTypeLegal(Type *Ty, MVT &VT) {
   EVT evt = TLI.getValueType(Ty, true);
   // Only handle simple types.
   if (evt == MVT::Other || !evt.isSimple())
     return false;
   VT = evt.getSimpleVT();
unsigned MipsFastISel::MaterializeGV(const GlobalValue *GV, MVT VT) {
   if (IsThreadLocal)
     return 0;
   BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::LW), DestReg)
       .addReg(MFI->getGlobalBaseReg())
       .addGlobalAddress(GV, 0, MipsII::MO_GOT);
   return DestReg;
 }
 unsigned MipsFastISel::MaterializeInt(const Constant *C, MVT VT) {
-  if (VT != MVT::i32)
+  if (VT != MVT::i32 && VT != MVT::i16 && VT != MVT::i8 && VT != MVT::i1)
     return 0;
   const TargetRegisterClass *RC = &Mips::GPR32RegClass;
-  // If the constant is in range, use a load-immediate.
   const ConstantInt *CI = cast<ConstantInt>(C);
-  if (isInt<16>(CI->getSExtValue())) {
+  int64_t Imm;
+  if (CI->isNegative())
+    Imm = CI->getSExtValue();
+  else
+    Imm = CI->getZExtValue();
+  return Materialize32BitInt(Imm, RC);
+}
+
+unsigned MipsFastISel::Materialize32BitInt(int64_t Imm,
+                                           const TargetRegisterClass *RC) {
+  unsigned ResultReg = createResultReg(RC);
+
+  if (isInt<16>(Imm)) {
     unsigned Opc = Mips::ADDiu;
-    unsigned ImmReg = createResultReg(RC);
-    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ImmReg)
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Opc), ResultReg)
         .addReg(Mips::ZERO)
-        .addImm(CI->getSExtValue());
-    return ImmReg;
+        .addImm(Imm);
+    return ResultReg;
+  } else if (isUInt<16>(Imm)) {
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::ORi),
+            ResultReg)
+        .addReg(Mips::ZERO)
+        .addImm(Imm);
+    return ResultReg;
   }
-  return 0;
+  unsigned Lo = Imm & 0xFFFF;
+  unsigned Hi = (Imm >> 16) & 0xFFFF;
+  if (Lo) {
+    // Both Lo and Hi have nonzero bits.
+    unsigned TmpReg = createResultReg(RC);
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::LUi),
+            TmpReg).addImm(Hi);
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::ORi),
+            ResultReg)
+        .addReg(TmpReg)
+        .addImm(Lo);
+
+  } else {
+    BuildMI(*FuncInfo.MBB, FuncInfo.InsertPt, DbgLoc, TII.get(Mips::LUi),
+            ResultReg).addImm(Hi);
+  }
+  return ResultReg;
 }
 
 namespace llvm {
 FastISel *Mips::createFastISel(FunctionLoweringInfo &funcInfo,
                                const TargetLibraryInfo *libInfo) {
   return new MipsFastISel(funcInfo, libInfo);
 }
 }

test/CodeGen/Mips/Fast-ISel/simplestorei.ll

+; RUN: llc -march=mipsel -relocation-model=pic -O0 -mips-fast-isel -fast-isel-abort -mcpu=mips32r2 \
+; RUN:     < %s | FileCheck %s
+
+@ijk = external global i32
+
+; Function Attrs: nounwind
+define void @si2_1() #0 {
+entry:
+  store i32 32767, i32* @ijk, align 4
+; CHECK:  .ent  si2_1
+; CHECK:        addiu $[[REG1:[0-9]+]], $zero, 32767
+; CHECK:  lw  $[[REG2:[0-9]+]], %got(ijk)(${{[0-9]+}})
+; CHECK:  sw  $[[REG1]], 0($[[REG2]])
+
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @si2_2() #0 {
+entry:
+  store i32 -32768, i32* @ijk, align 4
+; CHECK:  .ent  si2_2
+; CHECK:        addiu $[[REG1:[0-9]+]], $zero, -32768
+; CHECK:  lw  $[[REG2:[0-9]+]], %got(ijk)(${{[0-9]+}})
+; CHECK:  sw  $[[REG1]], 0($[[REG2]])
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @ui2_1() #0 {
+entry:
+  store i32 65535, i32* @ijk, align 4
+; CHECK:  .ent  ui2_1
+; CHECK:        ori $[[REG1:[0-9]+]], $zero, 65535
+; CHECK:  lw  $[[REG2:[0-9]+]], %got(ijk)(${{[0-9]+}})
+; CHECK:  sw  $[[REG1]], 0($[[REG2]])
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @ui4_1() #0 {
+entry:
+  store i32 983040, i32* @ijk, align 4
+; CHECK:  .ent  ui4_1
+; CHECK:        lui $[[REG1:[0-9]+]], 15
+; CHECK:  lw  $[[REG2:[0-9]+]], %got(ijk)(${{[0-9]+}})
+; CHECK:  sw  $[[REG1]], 0($[[REG2]])
+  ret void
+}
+
+; Function Attrs: nounwind
+define void @ui4_2() #0 {
+entry:
+  store i32 719566, i32* @ijk, align 4
+; CHECK:  .ent  ui4_2
+; CHECK:        lui $[[REG1:[0-9]+]], 10
+; CHECK:  ori $[[REG1]], $[[REG1]], 64206
+; CHECK:  lw  $[[REG2:[0-9]+]], %got(ijk)(${{[0-9]+}})
+; CHECK:  sw  $[[REG1]], 0($[[REG2]])
+  ret void
+}
+
+attributes #0 = { nounwind "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+